Matrix metalloproteinase inhibitors: A structure-activity study

J . Med. Chem. 1998, 41, 199-223

199

Ma tr ix Meta llop r otein a se In h ibitor s: A Str u ctu r e-Activity Stu d y

Daniel E. Levy,*^,†France Lapierre,^‡Weisheng Liang, Wenqing Ye, Christopher W. Lange, Xiaoyuan Li,

Damian Grobelny, Marie Casabonne, David Tyrrell, Kevin Holme,^‡Alex Nadzan, and Richard E. Galardy

Departments of Chemistry and Biochemistry, Glycomed, Inc., 860 Atlantic Avenue, Alameda, California 94501

Received J uly 29, 1997^X

Modifications around the dipeptide-mimetic core of a hydroxamic acid based matrix metallo-

proteinase inhibitor were studied. These variations incorporated a variety of natural, unnatural,

and synthetic amino acids in addition to modifications of the P1′ and P3′ substituents. The

results of this study indicate the following structural requirements: (1) Two key hydrogen

bonds must be present between the enzyme and potent substrates. (2) Potent inhibitors must

possess strong zinc-binding functionalities. (3) The potential importance of the hydrophobic

group at position R3 as illustrated by its ability to impart greater relative potency against

stromelysin when larger hydrophobic groups are used. (4) Requirements surrounding the

nature of the amino acid appear to be more restrictive for stromelysin than for neutrophil

collagenase, 72 kDa gelatinase, and 92 kDa gelatinase. These requirements may involve planar

fused-ring aryl systems and possibly hydrogen-bonding capabilities.

In tr od u ction

laminin, fibronectin, and elastin. Recent X-ray crystal-

lographic analyses of MMPs, with and without bound

inhibitors, have helped to elucidate the nature of the

interactions existing between small molecule MMPIs

and the corresponding enzymes.^21-24

An essential component of the inflammatory process

is the recruitment of leukocytes by the immune system

to a site of injury.¹These cells carry a variety of

enzymes essential for normal tissue defense and

repair,^2-4which include the matrix metalloproteinases

(MMPs). This family of enzymes includes the collage-

nases, gelatinases, and stromelysins. MMPs are neces-

sary for tissue remodeling and the healing cascade.^2,5

However, the overexpression of MMP activity or the

presence of MMP activity in healthy and uninjured

areas can contribute to the pathophysiology of a variety

of disease states and conditions. For example, a wound

possessing an excess of MMP activity will not heal

normally and may become ulcerated.^6,7MMP activity

directed at healthy skin may be implicated in the

development of psoriasis.^8,9MMP-mediated degrada-

tion of myelin is postulated to be involved in the

pathogenesis of multiple sclerosis.^10-12Other MMP-

mediated indications of current interest are rheumatoid

arthritis,^13,14resulting from loss of collagen from carti-

lage, and osteoporosis,^15,16resulting from loss of collagen

from bone.

In addition to tissue destruction and remodeling,

MMPs are known to be essential for the growth of new

blood vessels. This process of angiogenesis is essential

for the vascularization and growth of tumors beyond the

size of approximately 2 mm in diameter.¹⁷Conse-

quently, MMP inhibitors (MMPIs) are currently under

investigation for their utility in slowing or halting the

progression of tumor growth and metastasis.¹⁸With all

the indications potentially treatable by MMPIs, these

compounds are actively being studied by numerous

groups as potentially useful new medicines.¹⁹

Shown in Figure 1 is a representation of the fibroblast

collagenase binding site with a bound inhibitor. The

interactions shown are predicted from published X-ray

data involving fibroblast collagenase and a related

inhibitor.²⁰Comparisons of available crystallographic

information indicate significant sequence and structure

homology from one MMP to the next. Thus, one may

predict the illustrated hydrophobic and hydrogen-bond-

ing interactions to qualitatively reflect analogous in-

teractions throughout this family of enzymes.

Intense interest in this class of compounds has

sparked a variety of studies designed to elucidate the

structural requirements for enhanced potency and

enzyme specificity.^25-27Generally, these studies have

focused on the effects surrounding modification of a

single inhibitor residue or of a specific inhibitor class.

We now report a systematic in vitro SAR study against

four MMPs (neutrophil collagenase, 72 kDa gelatinase,

92 kDa gelatinase, stromelysin) involving the modifica-

tion of six sites around a prototypical broad spectrum

hydroxamate-based dipeptide mimetic MMPI, 6a . Fig-

ure 2 illustrates the generic structure, based on the lead

molecule, Galardin (compound 6a ),²⁸which was utilized

as the template for the present study.

Ch em istr y

The inhibitors of the present study²⁹were prepared

utilizing three general approaches. The first, presented

in Schemes 1 and 2, represents the approach utilized

for the majority of the compounds presented herein

containing both natural³⁰and unnatural^31,32amino

acids. As shown, a BOC-protected amino acid 1 was

coupled to an amine utilizing CDI as an activating

agent. The yields for this reaction ranged from 50% to

99%. Following the coupling reaction, the BOC group

The MMPs are a family of zinc-binding metalloen-

dopeptidases capable of degrading extracellular matrix

(ECM) components²⁰including collagen, gelatin, myelin,

^†Current address: 3918 Christian Drive, Belmont, CA 94002.

^‡Current address: 30 Invincible Court, Alameda, CA 94501.

^XAbstract published in Advance ACS Abstracts, December 15, 1997.

Published on Web 01/15/1998

200 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Levy et al.

Sch em e 3. Preparation of Carboxylic Acids and

Substituted Hydroxamates

F igu r e 1. Compound 6a /fibroblast collagenase predicted

interactions.

essential in order to ensure progression of the coupling

reaction. Once the methyl ester 5 was isolated, conver-

sion to the corresponding hydroxamic acid 6 was ac-

complished by treatment with hydroxylamine under

basic conditions with yields ranging from 30% to 60%.

The specific intermediates and target compounds pre-

pared according to Schemes 1 and 2 are shown in Tables

1-3.

When carboxylic acids or modified hydroxamic acids

were desired, the methods shown in Scheme 3 were

applied. As illustrated, the methyl esters 5 were

hydrolyzed under acidic conditions to carboxylic acids

7 in 40-70% yields. Alternately, the hydroxamic acids

6 were selectively alkylated on the hydroxamate oxygen,

giving O-substituted hydroxamic acids 8. The yields for

this reaction ranged from 20% to 80%. The final

products associated with Scheme 3 are shown in Table

4.

F igu r e 2. Generic MMPI SAR templates.

Sch em e 1. Preparation of Amino Acid Amide

Hydrochloride Salts

Sch em e 2. Preparation of Hydroxamic Acids

To prepare the compounds shown in Scheme 2, the

common intermediate 4a was required in large quanti-

ties. The synthesis of this compound was achieved as

shown in Scheme 4. Maleic anhydride 9 was condensed

with isobutylene, and the resulting ene adduct was

reduced to 10, utilizing catalytic hydrogenation. Sub-

sequent methanolysis of the anhydride produced the

mixture of regioisomers 11 and 12. Separation and

resolution of the desired regioisomer 12 with (S)-

methylbenzylamine yielded the final product 4a . The

undesired regioisomer 11 was converted back to the

anhydride 10 via hydrolysis to the diacid followed by

dehydration with acetic anhydride. The isolated un-

desired stereoisomer 4b was similarly utilized, as al-

luded to in Scheme 2, in subsequent structure activity

studies.

Proof of the stereochemistry of intermediate 4a was

accomplished utilizing the asymmetric synthetic ap-

proach shown in Scheme 5. As illustrated, the acid

chloride 13a was coupled with a chiral auxiliary^33,34to

provide 14a in near quantitative yields. 14a was then

treated with LDA and tert-butyl bromoacetate to give

15a with high diastereomeric purity. The auxiliary was

then removed on treatment with hydrogen peroxide and

lithium hydroxide, giving the final product 4c. As

shown in Scheme 6, when 4c was utilized in the

synthesis of 5a , the isolated product was chemically and

physically identical with that obtained utilizing 4a .

As indicated in Scheme 5 and Table 5, the isobutyl

component of the core structure was replaced with alkyl

groups of increasing chain length. However, if we

consider that the stereochemical configuration of 4 is

Ta ble 1. BOC-Protected Amino Acids Utilized

compound

AA (abbreviation)

L-tryptophan (L-Trp)

R6

1a

1b

1c

1d

1e

1f

1g

1h

1j

1k

1l

1m

1n

1o

OH

D-tryptophan (D-Trp)

L-N-methyltryptophan (L-Trp(Me))

L-3-benzothienylalanine (L-3-Bal)

L-1-naphthylalanine (L-1-Nal)

L-2-naphthylalanine (L-2-Nal)

L-3-quinolylalanine (L-3-Qal)

L-8-quinolylalanine (L-8-Qal)

L-4,4′-biphenylalanine (L-4,4′-Bip)

L-phenylalanine (L-Phe)

L-3-pyridylalanine (L-3-Pal)

L-4-pyridylalanine (L-4-Pal)

L-tert-leucine (L-tert-Leu)

L-abrine (L-Abr)

was removed under acidic conditions, giving a quantita-

tive yield of an amine hydrochloride 3 which was then

coupled to the substituted succinic acid monoester 4 in

yields comparable to the first coupling step. It is

important to note that when basic groups at R5 and/or

R6 were present, the addition of triethylamine was

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 201

Ta ble 2. Intermediates and Products Associated with Schemes 1 and 2

identical with that of D-malic acid 16, then we can

propose the synthesis of analogues bearing alkoxy

groups as isobutyl replacements. As outlined in Scheme

7, D-malic acid was treated with 2,2-dimethoxypropane

to yield the acetonide 17. Conversion of 17 to the

methyl ester 18 was accomplished on treatment with

diazomethane. Following removal of the acetonide

under acidic aqueous conditions, the acid 19 was

converted to the benzyl ester 20 on treatment with

benzyl bromide. The free hydroxyl group of 20 was then

alkylated with a variety of groups utilizing silver oxide

methodology, affording the ethers 21. In the final step,

catalytic hydrogenation of the ether analogues 21

yielded compounds 4g and 4h (Table 6). Use of these

compounds according to Scheme 1 afforded the desired

analogues bearing alkoxy surrogates for the parent

isobutyl group (Table 3).

Where D-malic acid provides avenues into R3 alkoxy

analogues, L-malic acid allows the formation of R2

hydroxy analogues.^35-37As shown in Scheme 8, L-

dimethyl malate 22 was treated with LDA followed by

methallyl bromide yielding the alkylated compound 23.

Catalytic hydrogenation effected reduction of the olefin

and subsequent hydrolysis of the diester provided the

diacid 25. Treatment of the diacid with 2,2-dimethoxy-

propane and PTSA yielded the acetonide 26. This

acetonide was then coupled with an amino acid amide

to give compounds 27. Following cleavage of the ac-

etonides under acidic conditions, the resulting carboxylic

acids 7 were converted to the methyl esters 5 utilizing

202 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Levy et al.

Ta ble 3. Additional Intermediates and Products Associated with Scheme 2

substitutions

R3

compound

R1 (5)

R1 (6)

R2

AA

l-Trp

R6

5d d d

5eee

5fff

5ggg

5h h h

5iii

5jjj

5k k k

5lll

6d d d

MeO

tBuO

MeO

tBuO

MeO

tBuO

MeO

NHOH

H

(S)iBu

(R)iBu

(R)Bu

NHCH₃

l-Trp

l-tert-Leu

6eee

6fff

NHOH

(R)Bu

(R)Hex

(R)Oct

(R)O-iPr

(R)O-Pen

(R)iBu

6ggg

6h h h

6iii

6jjj

6k k k

NHOH

5m m m

5n n n

5ooo

(S)-OH

Ta ble 4. Products Associated with Scheme 3

compound

R1/R7ONH

R2

R3

AA

L-Trp

L-tert-Leu

L-Trp

R6

7a

7b

7c

7d

7e

7f

8a

8b

8c

OH

H

(R)-iBu

(R)-Bu

NHCH₃

(R)-Hex

(R)-Oct

(R)-iBu

(S)-OH

CH₃ONH

BnONH

CH₃OCOCH₂ONH

H

L-Trp

Sch em e 4. Preparation of Substituted Succinic Acid Monoesters

Ta ble 5. Intermediates and Products Associated with

Scheme 5

Sch em e 5. Asymmetric Preparation of Succinic Acid

Monoesters

compound

13, 14, 15

substitution

4

R1

R3

a

b

c

d

c

d

e

f

tBuO

(R)-iBu

(R)-nBu

(R)-nHex

(R)-nOct

SAR An a lysis. The compounds of the present study

were assayed against MMPs, utilizing a fluorogenic

substrate in a 96-well plate format. This assay was

based on a published MMP assay utilizing a coumarin-

labeled peptidic substrate.³⁸All data are presented as

K_ivalues (nM).

When comparing the activities of the compounds

prepared for this study, several structure-activity

relationships become apparent. Beginning with com-

pound 6a , we find that the stereochemistry of the amino

diazomethane. Completion of the synthesis was

achieved, as previously described, on treatment with

hydroxylamine under basic conditions. The intermedi-

ates and products associated with Scheme 8 are shown

in Table 7.

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 203

Sch em e 6. Preparation of R₃Alkyl Analogues

92 kDa gelatinase, and 72 kDa gelatinase. However,

the substitution of L-tryptophan with L-tert-leucine

produced a 5-fold loss in potency against stromelysin.

This will be discussed below in the context of amino acid

modifications.

Structural modifications of the R3 substituent (isobu-

tyl for compound 6a ) provided insight into the structural

requirements of the P1′ binding site. The specific

modifications were chosen based upon two criteria.

First, the optimal size and shape of the R3 substituent

was in question. Second, compound 4a , and related

starting materials, are expensive and tedious to prepare.

If readily available chiral pool materials could be

utilized in the synthesis of analogues or bioisosteres of

4a , the preparation of inhibitors similar to those of the

present study may become simpler and more economi-

cal.

Ta ble 6. Products Associated with Scheme 7

compound

R1

R3

4g

4h

CH₃O

(R)-OiPr

(R)-OPen

As shown in Table 11, replacing an isobutyl group

with other hydrophobic groups caused little change in

the activities against neutrophil collagenase, 72 kDa

gelatinase, and 92 kDa gelatinase. However, com-

pounds 6fff and 6ggg, possessing hexyl and octyl

groups, respectively, as the R3 substituents, appeared

to have improved potency against stromelysin as com-

pared to compound 6a . This observation supports

stromelysin possessing a substantially deeper P1′ bind-

ing pocket compared to the other three enzymes studied

and is consistent with published SAR studies alluding

to the nature of the P1′ substituent and the potencies

of related inhibitors as tested against this enzyme.^26,44

Additionally, numerous reports focusing on the three-

dimensional structure of stromelysin have elaborated

upon the size and depth of this pocket as it appears to

be unique to this enzyme.^45-47With respect to the

gelatinases, the IC₅₀s of matlystatin analogues were

shown to gain 1-2 orders of magnitude when the P1′

group was extended to a nonyl group,²⁷and in similar

studies, substituted phenylpropyl substituents were

reported to give low picomolar K_i’s.⁴⁸Although the

compounds of the present study do not include aryl

groups at the P1′ site, the trend differences noted

between the matlystatins and compounds 6fff and 6ggg

may be attributed to structural variations associated

with the inhibitor backbones.

acid residue as well as the stereochemistry of the R3

substituent are essential for low nanomolar potency.

This is illustrated when noting that compound 6bb

utilizes D-Trp and compound 6d d d possesses the S

configuration for the R3 substituent. As shown in Table

8, these compounds display substantially lower poten-

cies compared to the parent compound. The stereo-

chemical requirements established herein are further

supported by the stereochemical configuration of the

natural substrates of the MMPs.³⁷

Having established the stereochemical requirements

for optimal potency for this structural series, modifica-

tions of the parent compound, 6a , were studied at six

key sites. The first family of analogues was derived

from the modification of the hydroxamic acid functional-

ity. The results, shown in Table 9, illustrate the

importance of the 1,4-bidentate nature of the zinc

binding moiety as supported by the loss of potency noted

for O-substituted hydroxamic acids (compounds 8a , 8b,

and 8c). The need for a potent zinc chelator is further

demonstrated by the loss of 2 orders of magnitude in

the potency when the hydroxamic acid was replaced by

the carboxylic acid of compound 7a .

The observations surrounding compound 7a are con-

sistent with reports for other carboxylate-containing

inhibitors,²⁶as well as those possessing phosphorus, and

sulfur-based zinc-binding functionalities.^39,40MMPIs

with groups which bind more weakly to zinc usually

require a substituent capable of interacting at the P1

pocket.^41,42Though known to bind more weakly than

hydroxamate-based inhibitors, some compounds pos-

sessing carboxylate functionalities as the zinc-binding

component are reported to be orally bioavailable.⁴³

However, as hydroxamate-based analogues tend to bind

zinc more strongly than analogues with other types of

functionalities, inhibitors of this nature do not require

additional appendages to achieve high levels of potency.

Recent reports describing the potency and pharma-

cokinetic properties of BB2516³⁷(6k k k ) prompted us

to examine the importance of a hydroxyl group as the

R2 substituent in this series. As 6k k k was derived from

L-tert-leucine, comparisons were made against the par-

ent compound 6a , the tert-leucine analogue 6a a a , and

the R2-hydroxylated analogue of 6a , compound 6jjj. The

results, summarized in Table 10, show no significant

change in the potencies against neutrophil collagenase,

When an ether linkage was explored as a novel

approach to join hydrophobic R3 groups to the inhibitor

backbone (compounds 6h h h and 6iii), a significant loss

in potency was observed. An explanation for this

observation could involve a shift in the conformation of

the inhibitor causing the need for a greater change in

free energy in order for binding to occur. Alternately,

the entrance to the P1′ binding pocket may possess

residues not compatible with the presence of heteroat-

oms. Potencies of similar magnitudes against human

fibroblast collagenase and human fibroblast stromelysin

have been reported for MMPIs with heteroatoms located

elsewhere on the P1′ substituent.⁴⁹

Considering functionalization of the N-terminus of the

amino acid component (R4 substituent), replacement of

the hydrogen with a methyl group (6bbb) induced a 2

orders of magnitude reduction in potency compared to

compound 6a . Comparable results were noted with

204 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Sch em e 7. Preparation of R₃Alkoxy Analogues

Levy et al.

Sch em e 8. Preparation of R₂Hydroxy Analogues

Ta ble 7. Intermediates and Products Associated with

Scheme 8

planar fused-ring aryl systems and possibly hydrogen-

bonding capabilities.

27

7

5

6

AA

L-Trp

L-tert-Leu

The subtle importance of the P2′ substituent relative

to potency and selectivity is further supported by a

recent combinatorial approach to the synthesis of MM-

PIs which incorporated an analysis of the effect of

varying the amino acid substituent.⁵⁰Analogues pos-

sessing aromatic, heteroaromatic, and aliphatic side

chains were tested against human collagenase. The

results indicated weaker potencies associated with

phenylalanine compared to leucine, tryptophan, 2-thie-

nylalanine, and 3-pyridylalanine.

Considering the terminal amide (R6 substituent),

some variability in the potencies was noted relative to

compound 6a . Hydrophobic amide residues (present on

compounds 6b, 6d , 6e, and 6f) caused little effect on

the relative potencies. The two exceptions involve the

weaker inhibition noted for longer chain hydrophobic

groups (compound 6b) and the significantly improved

stromelysin activity noted when a N-cyclopropylamide

(compound 6e) was incorporated in the inhibitor. As

noted with compound 6c, incorporation of a hydrophilic

residue on the amide did not diminish potency. Of

particular interest is the importance of the stereochem-

istry of the center bearing the amide nitrogen. As

illustrated by compounds 6g-j, a significant dependence

linking potency to the stereochemical configuration

exists. Of the remaining analogues prepared, the pres-

ence of aryl and heteroaryl amide residues was broadly

tolerated. One outlier is the (aminomethyl)benzimida-

zolyl group present in compound 6u . Finally, the

incorporation of doubly substituted amides at the in-

a

b

e

f

n n n

ooo

jjj

k k k

compound 6ccc, the methylated version of compound

6w . These data, shown in Table 12, support the

importance of the hydrogen bonding interaction present

between the internal amide proton and the enzyme

backbone.^20,37

Among the most extensive modifications studied were

substitutions involving the amino acid residue (R5

substituent) and the terminal amide residue (R6 sub-

stituent). The results of these studies are summarized

in Tables 13 and 14.

As shown in Table 13, the nature of the amino acid

residues studied in the present report caused little or

no effect on the potency of the inhibitors against

neutrophil collagenase, 72 kDa gelatinase, and 92 kDa

gelatinase compared to compound 6a . The most dra-

matic result in the neutrophil collagenase assay was

observed when biphenylalanine was incorporated at R5

(compound 6oo). This observation may imply a limit

to the size of the residue acceptable to these enzymes.

Finally, considering the stromelysin data, compounds

6oo, 6tt, and 6a a a appear to have weaker potencies.

This is interesting in view of the fact that the amino

acids utilized in these analogues possess hydrophobic

residues with no fused ring systems and no heteroatoms.

This may indicate that optimal spatial occupation of the

P2′ component of the stromelysin active site may require

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 205

Ta ble 8. Effect of Stereochemistry on Potency^a

entry

3

6

neutrophil collagenase

92 kDa gelatinase

72 kDa gelatinase

stromelysin

6a

6bb

6d d d

R

S

R

S

0.18 ( 0.09 (8)

390

54

0.57 ( 0.22 (7)

4500

270

0.39 ( 0.20 (10)

1800

300

26.0 ( 5.1 (8)

>1000

a

K_i(nM) values are reported against four MMPs.

Ta ble 9. Effect of Varying the R₁Substituent^a

entry

R₁

neutrophil collagenase

92 kDa gelatinase

72 kDa gelatinase

stromelysin

26.0 ( 5.1 (8)

39000

6a

7a

8a

8b

8c

HONH

HO

0.18 ( 0.09 (8)

17.0

7.70 ( 0.72 (2)

16.0 ( 5.8 (4)

460

0.57 ( 0.22 (7)

0.39 ( 0.20 (10)

170.0

6.30

11.0

71000

100

7.90

13.0

580

CH₃ONH

100

BnONH

480 ( 55 (2)

46000

CH₃OCOCH₂ONH

a

K_i(nM) values are reported against four MMPs.

Ta ble 10. Effect of Varying the R₂Substituent^a

entry

R₂

AA

L-Trp

L-tert-Leu

neutrophil collagenase

92 kDa gelatinase

72 kDa gelatinase

stromelysin

6a

6jjj

6a a a

6k k k

H

OH

H

0.18 ( 0.09 (8)

0.41

0.65 ( 0.14 (2)

0.53

0.57 ( 0.22 (7)

1.70 ( 0.83 (5)

2.50 ( 0.75 (5)

2.30 ( 0.70 (27)

0.39 ( 0.20 (10)

26.0 ( 5.1 (8)

20.0

130

13.0 ( 2.1 (3)

0.89

1.10

0.47

OH

a

K_i(nM) values are reported against four MMPs.

Ta ble 11. Effect of Varying the R₃Substituent^a

entry

R₃

iBu

Bu

Hex

Oct

neutrophil collagenase

92 kDa gelatinase

72 kDa gelatinase

stromelysin

6a

6eee

6fff

6ggg

6h h h

6iii

0.18 ( 0.09 (8)

0.30

0.24 ( 0.14 (3)

1.6

12.0

7.8

0.57 ( 0.22 (7)

0.54 ( 0.25 (3)

0.41 ( 0.16 (6)

0.63 ( 0.24 (4)

18.0 ( 7.3 (2)

26.0

0.39 ( 0.20 (10)

0.57

0.21 ( 0.03 (2)

0.66

42.0

43.0

26.0 ( 5.1 (8)

41.0 ( 6.5 (2)

8.3 ( 2.6 (2)

12.3 ( 0.2 (2)

830

700

O-iPr

O-Pen

a

K_i(nM) values are reported against four MMPs.

hibitor terminus (compounds 6x-z,a a ) caused a drop

in potency. This result is consistent with the impor-

tance of an additional hydrogen bond between the

Presently, few reports are available addressing as-

pects of the R6 SAR.^26,27,51However, the published

analyses indicate that the P3′ residue provides little

influence on the relative inhibitory activities. Of par-

ticular interest is the role the R6 substituent plays in

affecting the degree of biliary excretion of hydroxamate-

terminal amide proton and the enzyme active sites.²⁰

A

similar reduction in potency was reported with respect

to matlystatin analogues.²⁷

206 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Ta ble 12. Effect of Varying the R₄Substituent^a

Levy et al.

a

K_i(nM) values are reported against four MMPs.

Ta ble 13. Effect of Varying the AA (R₅) Substituent^a

entry

AA

L-Trp

L-Trp(Me)

L-3-Bal

L-1-Nal

L-2-Nal

L-3-Qal

L-8-Qal

L-4,4¢-Bip

L-Phe

neutrophil collagenase

92 kDa gelatinase

72 kDa gelatinase

stromelysin

6a

0.18 ( 0.09 (8)

0.57 ( 0.22 (7)

1.60 ( 0.59 (2)

0.83 ( 0.11 (5)

1.30 ( 0.71 (5)

0.99 ( 0.43 (3)

0.70 ( 0.16 (4)

1.50 ( 0.91 (5)

4.1 ( 1.5 (3)

0.39 ( 0.20 (10)

26.0 ( 5.1 (8)

31.0

6cc

6d d

6ee

6gg

6ll

0.66

0.45

0.44

14.0

0.64

0.42

46.0

1.3

1.0

0.7

51.0

1.0

66.0

6m m

6oo

6tt

6vv

6a a a

0.54

1.3

58.0

2.4

4.0

140

120

85.0 ( 7.0 (2)

130

0.82

0.96 ( 0.21 (3)

2.8 ( 1.5 (21)

2.50 ( 0.75 (5)

0.70

L-4-Pal

L-tert-Leu

1.7 ( 1.4 (2)

0.96 ( 0.17 (2)

0.65 ( 0.14 (2)

1.1

a

K_i(nM) values are reported against four MMPs.

based MMPIs following iv administration to rats.⁵¹The

present study demonstrates a dependence of stereo-

chemistry of R6 substituents on the in vitro potency of

hydroxamate-based inhibitors.

Con clu sion s

The MMPI series of the present study illustrates

many key points relevant to, and consistent with, the

structural requirements for inhibitors of MMPs. First,

the requirement for two key hydrogen bonds between

the enzyme and potent test agents was supported by

the drop in activity noted when tertiary amides were

present as part of either the amino acid portion or the

terminal amide. Second, the hydroxamic acid analogues

were consistently more potent than the carboxylic acid

analogues studied. This likely reflects the superior zinc

binding interaction of the 1,4-bidentate hydroxamic acid

ligand versus the 1,3-bidentate or monodentate interac-

tion with carboxylic acids. Third, the potential impor-

tance of a hydrophobic group at position R3 is illustrated

by the greater relative potency against stromelysin for

analogues with larger hydrophobic groups. Other groups

have seen increased potencies against gelatinases with

compounds possessing large hydrophobic aryl substit-

uents at R3 but, this was not observed for the alkyl

substituents of the present study. The reduced potency

of the R3 ether units could be related to the hydropho-

bicity requirements although it more likely reflects

steric interactions resulting from torsional differences.

In the final phase of our study, we explored the

modification of both the R5 and R6 sites. Interestingly,

the relative potencies of this series compared to com-

pound 6a showed either no improvement or a loss of

activity. These results, summarized in Table 15, failed

to show any synergistic or additive effects between the

most potent of the R5 and R6 analogues.

Although most reported SAR studies involve the

systematic modification of individual sites on a given

inhibitor backbone, few reports actually address the

potential for synergy between the sites studied. One

notable example, however, links the nucleophilic nitro-

gen present on the tryptophan residue to the terminal

amide, thus providing a series of analogues modified

simultaneously at the R5 and R6 positions.⁵²The

analogues of this study tended to show improved

potency in their hydroxamic acid or carboxylic acid

forms when compared to analogous materials bearing

no tether between the R5 and R6 substituents.

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 207

Ta ble 14. Effect of Varying the R₆Substituent^a

a

K_i(nM) values are reported against four MMPs.

208 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Ta ble 15. Effects of Combined R₅/R₆Modifications^a

Levy et al.

a

K_i(nM) values are reported against four MMPs.

purification. ¹H NMR spectra were recorded utilizing a Varian

Gemini 300 MHz spectrometer or a Varian VXR 500S 500 MHz

spectrometer. Optical rotations were determined utilizing a

Perkin-Elmer 241 polarimeter. Chromatography generally

refers to flash silica gel chromatography (J . T. Baker, 40 µM,

flash chromatography silica gel) and TLC (Analtech precoated

TLC plates, silica gel GHLF).

Finally, requirements surrounding the nature of the

amino acid appear to be more restrictive for stromelysin

that for the other three enzymes studied. These re-

quirements may involve planar fused-ring aryl systems

and possibly hydrogen bonding capabilities as illus-

trated by the weaker stromelysin activities noted for

analogues possessing aliphatic hydrophobic residues

and nonfused aryl residues.

None of the analogues incorporating two or more

features from this study that independently improved

potency provided any synergistic, or even additive,

inhibition. However, the SAR results from this work,

and SAR and structural work at other groups within

various analogue series, all suggest that more potent

and more selective MMPIs can be produced. Continued

work on broad spectrum MMPIs such as those of the

present study as well as those discussed elsewhere

coupled with work on novel emerging inhibitors should

provide new insights into the role of MMPs in disease

and the therapeutic potential of MMPIs.

HPLC analyses were carried out on a VYDAC C18 analytical

column (4.6 × 250 mm) utilizing the following methods.

Solvent A ) 10 mM H₃PO₄in 5% CH₃CN/H₂O. Solvent B )

10 mM H₃PO₄in 70% CH₃CN/H₂O. Solvent C ) 10 mM H₃-

PO₄in CH₃CN. HPLC method A ) 90% solvent A/10% solvent

B to 100% solvent B over 15 min with an additional 2 min at

100% solvent B. HPLC method B ) 70% solvent A/30%

solvent B to 100% solvent B over 16 min. HPLC method C )

80% solvent A/20% solvent B to 20% solvent A/80% solvent B

over 28 min. HPLC method D ) 80% solvent A/20% solvent

B to 20% solvent A/80% solvent B over 30 min with an

additional 3 min at 100% solvent B. HPLC method E ) 80%

solvent A/20% solvent B to 100% solvent B over 30 min. HPLC

method F ) 100% solvent A to 100% solvent B over 30 min.

HPLC method G ) 100% solvent A to 75% solvent A/25%

solvent B over 2 min with an additional 30 min at 75% solvent

A/25% solvent B. HPLC method H ) 80% solvent A/20%

solvent B for 30 min. HPLC method I ) 60% solvent A/40%

solvent B for 30 min. HPLC method J ) 75% solvent A/25%

solvent B for 30 min. HPLC method K ) 50% solvent A/50%

solvent B for 30 min. HPLC method L ) 65% solvent A/35%

Exp er im en ta l Section

Gen er a l P r oced u r e. Commercially available reagents and

starting materials were obtained from Aldrich, Sigma, Fluka,

Indofine, and Synthetech and were used with no additional

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 209

solvent B for 30 min. HPLC method M ) 1% solvent A/99%

H₂O to 50% solvent A/50% H₂O over 35 min. All flow rates

were set at 1 mL/minute.

vacuum to give the diacid (162.8 g, 93.6% yield). The diacid

was heated with acetic anhydride (150 mL) under a 10 in.-

vacuum jacketed Vigreux column. Acetic acid was removed

over several hours at 118-120 °C. When the temperature

began to fall, the pressure was gradually reduced to remove

the excess acetic anhydride. Isobutylsuccinic anhydride (138

g, 88.5% yield) was collected by distillation (P ) 10 mmHg, T

) 144 °C). ¹H NMR (300 MHz, CDCl₃): δ 0.95 (dd, 6H), 1.5

(m, 1H), 1.65-1.8 (m, 1H), 1.8-1.9 (m, 1H), 2.65 (m, 1H),

3.05-3.2 (m, 2H).

(R)-2-Isobu tyl-3-(m eth oxycar bon yl)pr opion ic Acid (4a).

D,L-2-Isobutyl-3-(methoxycarbonyl)propionic acid (12, 17.55 g,

93.35 mmol) was dissolved in diethyl ether (85 mL), and (S)-

methylbenzylamine (13.24 mL, 102.69 mmol) was added. The

reaction mixture was stirred at room temperature for 24 h,

and the solids were removed by filtration. Recrystallization

of the solids from ethanol/diethyl ether provided white crystal-

line needles (9.24 g, 32% mass recovery, 64% yield) as a single

diastereomer: ¹H NMR (300 MHz, CDCl₃): δ 0.9 (dd, 6H), 1.25

(m, 1H), 1.5-1.65 (m, 5H), 2.4 (dd, 1H), 2.6 (dd, 1H), 2.8 (m,

1H), 3.625 (s, 3H), 4.3 (m, 1H), 7.25-7.45 (m, 5H).

Human recombinant neutrophil collagenase was provided

by Dr. Karen Hasty (University of Tennessee). Human 72 kDa

gelatinase was provided by Dr. Henning Birkedal-Hansen

(University of Alabama) and Dr. Eric Howard (University of

Oklahoma). Human 92 kDa gelatinase/TIMP-1 complex was

provided by Dr. Eric Howard (University of Oklahoma).

Human recombinant stromelysin was provided by Dr. Hideaki

Nagase (University of Kansas).

Isobu tylsu ccin ic An h yd r id e (10). Maleic anhydride, 9

(750 g, 7.65 mol), was dissolved in hot toluene (500 mL),

filtered, and allowed to cool, thus producing a finely divided

crystalline precipitate. The resulting mixture was further

cooled to 10 °C overnight. 2-Methylpropene was condensed

into cold toluene (1 L). The cold maleic anhydride suspension

was transferred, with the aid of additional toluene (300 mL),

to the glass liner of a Parr 2 gallon stirred autoclave. The

2-methylpropene solution was then added followed by 4-tert-

butylcatechol (2 g). The autoclave was sealed and heated, with

stirring, to 170 °C over 45 min and maintained at that

temperature for an additional 9.5 h. The reaction was then

allowed to cool to 60 °C over 7 h after which the autoclave

was vented. After an additional 1.5 h, the internal tempera-

ture had reached 45 °C and the autoclave was opened. The

solvent was removed and the residue was distilled under

aspirator pressure through a 10 in. vacuum-jacketed Vigreux

column fitted with a partial take off head to give unreacted

maleic anhydride (139.4 g, 18.6% yield) and â-methallylsuc-

cinic anhydride (765.3 g, 79.8% yield). ¹H NMR (300 MHz,

CDCl₃): δ 1.7 (s, 3H), 2.3 (dd, 1H), 2.7 (m, 2H), 3.0 (dd, 1H),

3.25-3.35 (m, 1H), 4.75 (s, 1H), 4.9 (s, 1H).

â-Methallylsuccinic anhydride (539 g, 3.50 mol) was dis-

solved in toluene (800 mL) in a 1700 mL Parr stainless steel

bottle fitted with a heating jacket. The 10% Pd/C (3.60 g) was

added, and the bottle was connected to a Parr 2 L shaker fitted

with two 4 L hydrogen tanks. After several evacuations and

refilling with hydrogen, the shaker was started with the heater

controlled for 60 °C. The initial pressure was 60 lbs. When

the pressure fell to 10 lbs, the tanks were repressurized to 60

lbs. After 2 h, the controller was reset to 70 °C, and the

reaction was continued for another 12 h. The heat was then

turned off, and after another 5 h, the shaker was stopped. The

reaction vessel was evacuated, and the reaction mixture was

filtered and concentrated. Distillation of the residue through

the Vigreux column described above (P ) 9-10 mmHg, T )

180 °C) gave isobutylsuccinic anhydride (532.9 g, 97.6% yield).

¹H NMR (300 MHz, CDCl₃): δ 0.95 (dd, 6H), 1.5 (m, 1H), 1.65-

1.8 (m, 1H), 1.8-1.9 (m, 1H), 2.65 (m, 1H), 3.05-3.2 (m, 2H).

The isolated crystalline needles (1.29 g, 4.18 mmol) were

dissolved in CHCl₃(100 mL) and washed with 1 N HCl (3 ×

20 mL) and brine (20 mL). The organics were dried over

anhydrous MgSO₄, filtered, and concentrated to give 4a (0.77

g, 98% yield, [R]_D) +19.8) as a single enantiomer of greater

than 97% optical purity. ¹H NMR (300 MHz, CDCl₃): δ 0.95

(dd, 6H), 1.5 (m, 1H), 1.65-1.8 (m, 1H), 1.8-1.9 (m, 1H), 2.65

(m, 1H), 3.05-3.2 (m, 2H).

(S)-2-Isobu tyl-3-(m eth oxycar bon yl)pr opion ic Acid (4b).

The mother liquor from the isolation of 4a was concentrated

to dryness and dissolved in CHCl₃(100 mL). The resulting

solution was washed with 1 N HCl (3 × 20 mL) and brine (20

mL). The organics were dried over anhydrous MgSO₄, filtered,

and concentrated. The residue was dissolved in diethyl ether,

and (R)-methylbenzylamine (1.1 equiv) was added. The reac-

tion mixture was stirred at room temperature for 24 h, and

the solids were removed by filtration. Recrystallization of the

solids from ethanol/diethyl ether provided white crystalline

needles as

a

single diastereomer. ¹H NMR (300 MHz,

CDCl₃): δ 0.9 (dd, 6H), 1.25 (m, 1H), 1.5-1.65 (m, 5H), 2.4

(dd, 1H), 2.6 (dd, 1H), 2.8 (m, 1H), 3.625 (s, 3H), 4.3 (m, 1H),

7.25-7.45 (m, 5H).

The isolated crystalline needles were dissolved in CHCl₃

(100 mL) and washed with 1 N HCl (3 × 20 mL) and brine (20

mL). The organics were dried over anhydrous MgSO₄, filtered,

and concentrated to give 4b (95% yield, [R]_D) -20.1) as a

single enantiomer of greater than 96% optical purity. ¹H NMR

(300 MHz, CDCl₃): δ 0.95 (dd, 6H), 1.5 (m, 1H), 1.65-1.8 (m,

1H), 1.8-1.9 (m, 1H), 2.65 (m, 1H), 3.05-3.2 (m, 2H).

D,L-2-Isobu tyl-3-(m eth oxycar bon yl)pr opion ic Acid (12).

Isobutylsuccinic anhydride (501 g, 3.21 mol) was dissolved in

anhydrous methanol (500 mL) and allowed to stand at room

temperature for 5 days. The methanol was removed, and the

residue was mixed with petroleum ether (500 mL) and

refrigerated overnight. The solids were filtered, and the

filtrate was cooled to 0 °C. After 3 days, the solids were filtered

and the combined solids were recrystallized from petroleum

ether to give ^D,L-2-isobutyl-3-(methoxycarbonyl)propionic acid

(12, 337.5 g, 55.9% yield). ¹H NMR (300 MHz, CDCl₃): δ 0.9

(dd, 6H), 1.3 (m, 1H), 1.55-1.7 (m, 2H), 2.45 (dd, 1H), 2.65

(dd, 1H), 2.9 (m, 1H), 3.7 (s, 3H).

R egen er a t ion of Isob u t ylsu ccin ic An h yd r id e (10).

After the combined petroleum ether filtrates from above were

concentrated, 188 g (1 mol) of the crude material (mostly

consisting of 3-(methoxycarbonyl)-5-methylhexanoic acid) was

mixed with sodium hydroxide (120 g, 3 mol) and water (700

mL). The mixture was stirred on a steam bath for 14 h. The

mixture was filtered and acidified with concentrated sulfuric

acid (90 mL) and refrigerated. The suspension of sodium

sulfate and the diacid was filtered, and the solids were

thoroughly washed with ethyl acetate (500 mL). The aqueous

solution was washed with ethyl acetate, and the combined

ethyl acetate phases were concentrated and dried under

Gen er a l P r oced u r e A: P r ep a r a tion of N-Acyloxa zoli-

d in on es (14). (S)-4-Benzyl-2-oxazolidinone was dissolved in

dry THF (10 mL/g) and cooled to -78 °C under argon.

n-Butyllithium (1 equiv) was added over 10 min, and the

resulting mixture was stirred for 1 h at -78 °C. An acid

chloride (13, 1.1 equiv) was then added, the reaction mixture

was stirred for 1 h at -78 °C and allowed to warm to room

temperature over an additional 1 h. The reaction was quenched

with saturated NH₄Cl (50% total reaction volume), the THF

was removed under vacuum, and the aqueous phase was

washed with CH₂Cl₂(2×). The organic phase was then washed

with 1 N NaOH (1×) and brine (1×), after which it was dried

over anhydrous Na₂SO₄. The product was isolated following

filtration and removal of the solvent under vacuum. No

purification steps were required, and the isolated product was

utilized in the next step.

Gen er a l P r oced u r e B: P r ep a r a tion of Alk yla ted N-

Acyl Oxa zolid in on es (15). Lithium hexamethyldisilazide (1

M in THF) was cooled to -78 °C under argon and a solution

of an N-acyloxazolidinone (0.9 equiv) in dry THF (6 mL/g) was

added while the internal reaction temperature was maintained

below -65 °C. After 1 h of stirring at -78 °C, tert-butyl

bromoacetate (2.5 equiv) was added while the internal reaction

temperature was maintained below -70 °C. The resulting

210 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Levy et al.

mixture was stirred at -78 °C for 1 h and then allowed to

warm to -40 °C over an additional 1 h. The reaction mixture

was then warmed to 0 °C and the reaction quenched with

saturated NH₄Cl (50% total reaction volume). The THF was

removed under vacuum, and the aqueous phase was washed

with EtOAc (2×). The combined organic extracts were dried

over anhydrous Na₂SO₄, filtered, and concentrated. The

residue was purified on silica gel (15% EtOAc/hexane), thus

yielding the desired product.

Gen er a l P r oced u r e C: P r ep a r a tion of Su bstitu ted

Su ccin ic Acid Mon oester s 4. An alkylated N-acyloxazoli-

dinone, 16, was dissolved in THF/H₂O (4/1, 10 mL/g) and cooled

to 0 °C. Hydrogen peroxide (30% in water, 0.62 mL/mmol)

was added followed by a solution of LiOH in water (1.18 M,

1.34 equiv). The reaction mixture was stirred at 0 °C for 3 h,

after which a solution of Na₂SO₃in water (2.73 M, 1.34 equiv)

was added over 10 min. The THF was then removed under

vacuum, and the remaining aqueous phase was washed with

CH₂Cl₂(3×). The organic phase was then washed with 0.1 N

NaOH (3×). The combined aqueous phases were acidified to

pH ) 2 with 2 N HCl and washed with EtOAc (3×). The

combined organic extracts were dried over anhydrous MgSO₄,

filtered, and concentrated to give the desired product. No

purification steps were required, and the isolated product was

utilized in the next step.

Gen er a l P r oced u r e D: P r ep a r a tion of BOC Am in o

Acid Am id es 2. A BOC-protected amino acid, 1, was dis-

solved in THF (7 mL/g) and followed by the addition of CDI (1

equiv). The resulting solution was stirred at room tempera-

ture for 2 h after which 1 equiv of a primary or secondary

amine was added. After 24 h of stirring at room temperature,

the reaction mixture was concentrated to dryness. The residue

was diluted with ethyl acetate (100 mL) and washed with

saturated NaHCO₃(3 × 20 mL), water (3 × 20 mL), and brine

(20 mL). After being dried over anhydrous MgSO₄, the

organics were concentrated to dryness yielding the desired

product. No purification steps were required, and the isolated

product was utilized in the next step.

Gen er a l P r oced u r e E: P r ep a r a tion of Am in o Acid

Am id e Hyd r och lor id es 3. A BOC amino acid amide (2, 1

g) was dissolved in MeOH (10 mL), and 4 N HCl in dioxane

(10 mL) was added. The reaction mixture was stirred at room

temperature for 4 h. Concentration of the reaction mixture

to dryness afforded the desired amine hydrochloride, 3, in a

quantitative yield. No purification steps were required, and

the isolated product was utilized in the next step.

concentrated to dryness. The residue was then dissolved in

H₂O (20 mL), acidified to pH ) 5 with 6 N HCl, and neutralized

with saturated NaHCO₃.

Workup procedures substantially varied from one compound

to the next. The following is provided to guide workup

procedures accordingly.

Typically, the product precipitated out and was collected by

filtration. Alternately, extraction of the product into 15%

MeOH/EtOAc may have been necessary. In cases of extreme

water solubility, the mixture was lyophilized and the product

was triturated from the salts with 2-propanol. Purification

of the product was accomplished either by recrystallization

from 2-propanol or by silica gel chromatography. If silica gel

was used, MeOH/CHCl₃mixtures may have been used for

elution. Residual silica gel was then removed from the isolated

product by trituration with 2-propanol. Final products were

isolated as dry materials, hydrates, or 2-propanol (C₃H₈O)

complexes.

Gen er a l P r oced u r e H: F or m a tion of O-Su bstitu ted

Hyd r oxa m ic Acid s 8. Compound 6 was dissolved in MeOH

(20 mL/g), and K₂CO₃(1.1 equiv) was added followed by an

alkyl halide (1.1 equiv). The reaction mixture was stirred at

room temperature for 24 h, after which the solvent was

removed under vacuum. The residue was partitioned between

EtOAc and H₂O. The organic phase was washed with brine

(3×), dried over anhydrous MgSO₄, filtered, and concentrated.

The residue was purified by recrystallization or silica gel

chromatography.

Gen er a l P r oced u r e I: Hyd r olysis of ter t-Bu tyl Ester s

to Acid s 7. A tert-butyl ester was dissolved in CH₂Cl₂(10

mL/g), and trifluoroacetic acid (4 mL/g) was added. The

reaction mixture was stirred at room temperature for 30 min,

after which it was concentrated to dryness. The residue was

placed under vacuum for 2 h and dissolved in EtOAc (5 mL/

g). The resulting solution was diluted with hexanes until the

product precipitated. The solids were collected by filtration

and dried under vacuum, giving the desired product. No

purification step was necessary with this procedure.

Gen er a l P r oced u r e J : F or m a tion of Meth yl Ester s 5.

A carboxylic acid was dissolved in MeOH or Et₂O (10 mL/g),

and a solution of CH₂N₂in Et₂O was added until a persistent

yellow color appeared. Acetic acid was then added dropwise

until the yellow color disappeared. The resulting solution was

concentrated to dryness, and the residue was dissolved in

EtOAc (100 mL). The organic phase was washed with

saturated NaHCO₃(3 × 25 mL) and brine (25 mL). After being

dried over anhydrous MgSO₄, the organic phase was filtered

and concentrated to dryness, providing the desired product.

No purification step was necessary with this procedure.

Gen er a l P r oced u r e K: F or m a tion of BOC-P r otected

Am in o Acid s 1. An amino acid was dissolved in dry DMF

(10 mL/g), and triethylamine (3 equiv) was added followed by

di-tert-butyl dicarbonate (1.1 equiv). The reaction mixture was

stirred at room temperature for 15 h, after which it was

concentrated to dryness and the residue was dissolved in

EtOAc (100 mL). The resulting mixture was washed with

saturated NaHCO₃(3 × 50 mL). The combined aqueous

extracts were acidified to pH ) 3 (pH paper) with 6 N HCl

and washed with EtOAc (3 × 50 mL). The combined organic

extracts were dried over anhydrous MgSO₄, filtered, and

concentrated to give the desired product. No purification was

necessary with this procedure.

Gen er a l P r oced u r e F : P r ep a r a tion of Am in o Acid

Am id e-Su ccin ic Acid Ad d u cts 5. A substituted succinic

acid monoester (4, 13, 17, or 22) was dissolved in THF (10

mL/g). CDI (1 equiv) was added, and the reaction mixture

was stirred at room temperature for 2 h. An amino acid amide

hydrochloride (3, 1 equiv) was dissolved or suspended in THF

(10 mL/g), and Et₃N (2 equiv) was added. The activated

succinic acid monoester solution was then transferred to the

amino acid amide hydrochloride via cannula. After 24-72 h

of stirring, the reaction mixture was concentrated to dryness.

The residue was diluted with EtOAc (100 mL) and washed

with saturated NaHCO₃(3 × 20 mL), water (3 × 20 mL), and

brine (20 mL). The organics were dried over anhydrous

MgSO₄, filtered, and concentrated. The residue was purified

on silica gel (50% EtOAc/hexane or CHCl₃/MeOH, 25/1).

Gen er a l P r oced u r e G: F or m a tion of Hyd r oxa m ic

Acid s 6. [Note: concentrations and reagent ratios are critical

to the success of this reaction.] Compound 5 (5 mmol) was

dissolved in MeOH (10 mL). HONH₂‚HCl (36 mmol) was

dissolved in MeOH (24 mL). KOH (57 mmol) was dissolved

in MeOH (16 mL). The KOH solution was poured into the

HONH₂‚HCl solution, and the resulting mixture was cooled

to 0 °C for 1 h. The KOH/HONH₂solution was then filtered

into the solution of compound 5, and the reaction mixture was

stirred at room temperature until complete by TLC [TLC

solvent ) CHCl₃/MeOH/H₂O, 150/45/5, total reaction time is

generally less than 15 min]. When TLC indicated total

consumption of starting material, the reaction mixture was

N-BOC-^L-[3-(1-m eth ylin d olyl)]a la n in e (1c). Compound

1c was prepared by subjecting N-methyltryptophan to general

procedure K. Yield ) 78%.

N-BOC-^L-ter t-leu cin e (1n ). Compound 1n was prepared

by subjecting ^L-tert-leucine to general procedure K. Yield )

64%. TLC: R_f) 0.56 (CHCl₃/MeOH/H₂O, 200/45/5).

N-BOC-^L-a br in e (1o). Compound 1o was prepared by

subjecting ^L-abrine to general procedure K. Yield ) 97%.

N-BOC-L-tr yp top h a n N-Meth yla m id e (2a ). Compound

2a was prepared by coupling N-BOC-^L-tryptophan, 1a , with

methylamine hydrochloride according to general procedure D.

Yield ) 97%.

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 211

N-BOC-L-tr yp top h a n N-1-P en tyla m id e (2b). Compound

2b was prepared by coupling N-BOC-tryptophan, 1a , with

1-aminopentane according to general procedure D. Yield )

92%.

N-BOC-^L-t r yp t op h a n N-(H yd r oxyet h yl)a m id e (2c).

Compound 2c was prepared by coupling N-BOC-tryptophan,

1a , with ethanolamine according to general procedure D. Yield

) 100%. TLC: R_f) 0.71 (10% MeOH/CHCl₃).

N-BOC-^L-tr yp top h a n N-[2-(Ca r boben zyloxya m in o)et-

h yl]a m id e (2d ). Compound 2d was prepared by coupling

N-BOC-tryptophan, 1a , with mono(carboxybenzyloxy)ethyl-

enediamine⁵³according to general procedure D. Yield ) 67%.

TLC: R_f) 0.50 (70% EtOAc/hexane).

N-BOC-^L-tr yp top h a n N-Cyclop r op yla m id e (2e). Com-

pound 2e was prepared by coupling N-BOC-tryptophan, 1a ,

with cyclopropylamine according to general procedure D. Yield

) 92%.

N-BOC-^L-tr yp top h a n N-Cyclop en tyla m id e (2f). Com-

pound 2f was prepared by coupling N-BOC-tryptophan, 1a ,

with cyclopentylamine according to general procedure D. Yield

) 90%.

N-BOC-^L-tr yptoph an N-[(S)-1-In dan yl]am ide (2g). Com-

pound 2g was prepared by coupling N-BOC-tryptophan, 1a ,

with (S)-1-aminoindan according to general procedure D. Yield

) 87%.

N-BOC-^L-tr yptoph an N-[(R)-1-In dan yl]am ide (2h ). Com-

pound 2h was prepared by coupling N-BOC-tryptophan, 1a ,

with (R)-1-aminoindan according to general procedure D.

Yield ) 83%.

N-BOC-^L-tr yp top h a n [(1R,2S)-2-Hyd r oxy-1-in d a n yl]a -

m id e (2i). Compound 2i was prepared by coupling N-BOC-

tryptophan, 1a , with (1R,2S)-1-amino-2-indanol according to

general procedure D. Yield ) 78%.

N-BOC-^L-tr yp top h a n [(1S,2R)-2-Hyd r oxy-1-in d a n yl]a -

m id e (2j). Compound 2j was prepared by coupling N-BOC-

tryptophan, 1a , with (1S,2R)-1-amino-2-indanol according to

general procedure D. Yield ) 76%.

N-BOC-^L-tr yp top h a n N-Ben zyla m id e (2k ). Compound

2k was prepared by coupling N-BOC-tryptophan, 1a , with

benzylamine according to general procedure D. Yield ) 98%.

N-BOC-^L-tr yp top h a n N-[(S)-Meth ylben zyl]a m id e (2l).

Compound 2l was prepared by coupling N-BOC-tryptophan,

1a , with (S)-methylbenzylamine according to general proce-

dure D. Yield ) 98%.

N-BOC-^L-tr yp top h a n P ip er on yla m id e (2m ). Compound

2m was prepared by coupling N-BOC-tryptophan, 1a , with

piperonylamine according to general procedure D. Yield )

91%.

N-BOC-^L-tr yp top h a n N-(4-P yr id ylm eth yl)a m id e (2n ).

Compound 2n was prepared by coupling N-BOC-tryptophan,

1a , with 4-(aminomethyl)pyridine according to general proce-

dure D. Yield ) 97%.

N-BOC-^L-tr yp top h a n N-(3-P yr id ylm eth yl)a m id e (2o).

Compound 2o was prepared by coupling N-BOC-tryptophan,

1a , with 3-(aminomethyl)pyridine according to general proce-

dure D. Yield ) 100%. TLC: R_f) 0.22 (EtOAc).

N-BOC-^L-tr yp top h a n N-(2-P yr id ylm eth yl)a m id e (2p ).

Compound 2p was prepared by coupling N-BOC-tryptophan,

1a , with 2-(aminomethyl)pyridine according to general proce-

dure D. Yield ) 100%. TLC: R_f) 0.33 (EtOAc).

N-BOC-^L-tr yp top h a n N-[2-(2-P yr id yl)eth yl]a m id e (2q).

Compound 2q was prepared by coupling N-BOC-tryptophan,

1a , with 2-(aminoethyl)pyridine according to general procedure

D. Yield ) 98%. TLC: R_f) 0.21 (EtOAc).

N-BOC-^L-tr yp top h a n N-[2-(4-Hyd r oxyp h en yl)eth yl]a -

m id e (2r ). Compound 2r was prepared by coupling N-BOC-

tryptophan, 1a , with tyramine according to general procedure

D. Yield ) 100%. TLC: R_f) 0.16 (50% EtOAc/hexane).

N-BOC-^L-tr yp top h a n F u r fu r yla m id e (2s). Compound 2s

was prepared by coupling N-BOC-tryptophan, 1a , with furfu-

rylamine according to general procedure D. Yield ) 90%.

N-BOC-^L-tr yp top h a n N-(2-Th ia zolylm eth yl)a m id e (2t).

Compound 2t was prepared by coupling N-BOC-tryptophan,

1a , with 2-(aminomethyl)thiazole⁵⁴according to general pro-

cedure D. Yield ) 83%. TLC: R_f) 0.15 (50% EtOAc/hexane).

N-BOC-^L-t r yp t op h a n

N-(2-Ben zim id a zolylm et h yl)-

a m id e (2u ). Compound 2u was prepared by coupling N-BOC-

tryptophan, 1a , with 2-(aminomethyl)benzimidazole according

to general procedure D. Yield ) 70%.

N-BOC-^L-tr yp top h a n N-[3-(1-Im id a zolylp r op yl)]a m id e

(2v). Compound 2v was prepared by coupling N-BOC-tryp-

tophan, 1a , with 1-(3-aminopropyl)imidazole according to

general procedure D. Yield ) 98%. TLC: R_f) 0.10 (5%

MeOH/CHCl₃).

N-BOC-^L-t r yp t op h a n

N-[3-(4-Mor p h olin ylp r op yl)]-

a m id e (2w ). Compound 2w was prepared by coupling N-

BOC-tryptophan, 1a , with 4-(3-aminopropyl)morpholine ac-

cording to general procedure D. Yield ) 96%. TLC: R_f) 0.56

(15% MeOH/CHCl₃).

N-BOC-^L-tr yp top h a n N,N-Dim eth yla m id e (2x). Com-

pound 2x was prepared by coupling N-BOC-tryptophan, 1a ,

with dimethylamine hydrochloride according to general pro-

cedure D. Yield ) 75%.

N-BOC-^L-t r yp t op h a n P yr olid in yla m id e (2y). Com-

pound 2y was prepared by coupling N-BOC-tryptophan, 1a ,

with pyrolidine according to general procedure D. Yield )

94%. TLC: R_f) 0.14 (50% EtOAc/hexane).

N-BOC-^L-t r yp t op h a n P ip er id in yla m id e (2z). Com-

pound 2z was prepared by coupling N-BOC-tryptophan, 1a ,

with piperidine according to general procedure D. Yield )

89%.

N-BOC-^L-tr yp top h a n Mor p h olin yla m id e (2a a ). Com-

pound 2a a was prepared by coupling N-BOC-tryptophan, 1a ,

with morpholine according to general procedure D. Yield )

100%. TLC: R_f) 0.42 (EtOAc).

N-BOC-^D-tr yp top h a n N-Meth yla m id e (2bb). Compound

2bb was prepared by coupling N-BOC-^D-tryptophan, 1b, with

methylamine hydrochloride according to general procedure D.

Yield ) 97%.

N-BOC-^L-[3-(1-m eth ylin d olyl)]a la n in e N-Meth yla m id e

(2cc). Compound 2cc was prepared by coupling N-BOC-1-

methyltryptophan, 1c, with methylamine hydrochloride ac-

cording to general procedure D. Yield ) 89%. TLC: R_f) 0.85

(MeOH/CHCl₃, 1/25).

N-BOC-^L-(3-ben zoth ien yl)alan in e N-Meth ylam ide (2dd).

Compound 2d d was prepared by coupling N-BOC-benzothie-

nylalanine, 1d , with methylamine hydrochloride according to

general procedure D. Yield ) 97%. TLC: R_f) 0.31 (50%

EtOAc/hexane).

N-BOC-^L-(1-n a p h th yl)a la n in e N-Meth yla m id e (2ee).

Compound 2ee was prepared by coupling N-BOC-1-naphthy-

lalanine, 1e, with methylamine hydrochloride according to

general procedure D. Yield ) 95%. TLC: R_f) 0.33 (50%

EtOAc/hexane).

N-BOC-^L-(1-n a p h th yl)a la n in e N-[3-(4-Mor p h olin ylp r o-

p yl)]a m id e (2ff). Compound 2ff was prepared by coupling

N-BOC-1-naphthylalanine, 1e, with 4-(3-aminopropyl)mor-

pholine according to general procedure D. Yield ) 90%.

TLC: R_f) 0.37 (hexane/EtOAc/MeOH 3/3/1).

N-BOC-^L-(2-n a p h th yl)a la n in e N-Meth yla m id e (2gg).

Compound 2gg was prepared by coupling N-BOC-2-naphthy-

lalanine, 1f, with methylamine hydrochloride according to

general procedure D. Yield ) 90%. TLC: R_f) 0.60 (10%

MeOH/CHCl₃).

N-BOC-^L-(2-n a p h th yl)a la n in e N-[3-(4-Mor p h olin ylp r o-

p yl)]a m id e (2h h ). Compound 2h h was prepared by coupling

N-BOC-2-naphthylalanine, 1f, with 4-(3-aminopropyl)morpho-

line according to general procedure D. Yield ) 77%. TLC:

R_f) 0.61 (CHCl₃/MeOH/H₂O, 30/9/1).

N-BOC-^L-(2-n a p h th yl)a la n in e N-[2-(4-Hyd r oxyp h en yl)-

eth yl]a m id e (2ii). Compound 2ii was prepared by coupling

N-BOC-2-naphthylalanine, 1f, with tyramine according to

general procedure D. Yield ) 95%. TLC: R_f) 0.67 (CHCl₃/

MeOH/H₂O, 30/9/1).

N-BOC-^L-(2-n a p h t h yl)a la n in e N-[(S)-Met h ylb en zyl]-

a m id e (2jj). Compound 2jj was prepared by coupling N-BOC-

2-naphthylalanine, 1f, with (S)-methylbenzylamine according

212 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Levy et al.

to general procedure D. Yield ) 89%. TLC: R_f) 0.89 (CHCl₃/

MeOH/H₂O, 30/9/1).

methylamine hydrochloride according to general procedure D.

Yield ) 56%. TLC: R_f) 0.15 (50% EtOAc/hexane).

N-BOC-^L-a b r in e N-[3-(4-Mor p h olin ylp r op yl)]a m id e

(2ccc). Compound 2ccc was prepared by coupling N-BOC-

abrine, 1o, with 4-(3-aminopropyl)morpholine according to

general procedure D. Yield ) 50%. TLC: R_f) 0.23 (5%

MeOH/CHCl₃).

L-Tr yptoph an N-Meth ylam ide Hydr och lor ide Salt (3a).

Compound 3a was prepared by subjecting compound 2a to

general procedure E. Yield ) 100%.

L-Tr yp t op h a n N-1-P en t yla m id e H yd r och lor id e Sa lt

(3b). Compound 3b was prepared by subjecting compound 2b

to general procedure E. Yield ) 100%.

L-Tr yp top h a n N-(Hyd r oxyeth yl)a m id e Hyd r och lor id e

Sa lt (3c). Compound 3c was prepared by subjecting com-

pound 2c to general procedure E. Yield ) 100%.

N-BOC-^L-(2-n a p h th yl)a la n in e N-Ben zyla m id e (2k k ).

Compound 2k k was prepared by coupling N-BOC-2-naphthy-

lalanine, 1f, with benzylamine according to general procedure

D. Yield ) 94%. TLC: R_f) 0.83 (CHCl₃/MeOH/H₂O, 30/9/1).

N-BOC-^L-(3-qu in olyl)alan in e N-Meth ylam ide (2ll). Com-

pound 2ll was prepared by coupling N-BOC-3-quinolylalanine,

1g, with methylamine hydrochloride according to general

procedure D. Yield ) 88%. TLC: R_f) 0.81 (10% MeOH/

CHCl₃).

N-BOC-^L-(8-qu in olyl)alan in e Meth ylam ide (2m m ). Com-

pound 2m m was prepared by coupling N-BOC-8-quinolylala-

nine, 1h , with methylamine hydrochloride according to general

procedure D. Yield ) 69%. TLC: R_f) 0.80 (10% MeOH/

CHCl₃).

N-BOC-^L-(4,4′-bip h en yl)a la n in e N-Meth yla m id e (2oo).

Compound 2oo was prepared by coupling N-BOC-4,4′-biphe-

nylalanine, 1j, with methylamine hydrochloride according to

general procedure D. Yield ) 83%. TLC: R_f) 0.0.77 (10%

MeOH/CHCl₃).

N-BOC-^L-(4,4′-bip h en yl)a la n in e N-[3-(4-Mor p h olin yl-

p r op yl)]a m id e (2p p ). Compound 2p p was prepared by

coupling N-BOC-4,4′-biphenylalanine, 1j, with (aminopropyl)-

morpholine according to general procedure D. Yield ) 72%.

TLC: R_f) 0.65 (CHCl₃/MeOH/H₂O, 30/9/1).

L-Tr yp t op h a n

N-[2-(Ca r b ob en zyloxya m in o)et h yl]-

a m id e Hyd r och lor id e Sa lt (3d ). Compound 3d was pre-

pared by subjecting compound 2d to general procedure E. Yield

) 100%.

L-Tr yptoph an N-Cyclopr opylam ide Hydr och lor ide Salt

(3e). Compound 3e was prepared by subjecting compound 2e

to general procedure E. Yield ) 100%.

L-Tr yptoph an N-Cyclopen tylam ide Hydr och lor ide Salt

(3f). Compound 3f was prepared by subjecting compound 2f

to general procedure E. Yield ) 100%.

L-Tr yp top h a n N-[(S)-1-In d a n yl]a m id e Hyd r och lor id e

Sa lt (3g). Compound 3g was prepared by subjecting com-

pound 2g to general procedure E. Yield ) 100%.

N-BOC-^L-(4,4′-bip h en yl)a la n in e N-[2-(4-Hyd r oxyp h e-

n yl)eth yl]a m id e (2qq). Compound 2qq was prepared by

coupling N-BOC-4,4′-biphenylalanine, 1j, with tyramine ac-

cording to general procedure D. Yield ) 92%. TLC: R_f) 0.63

(CHCl₃/MeOH/H₂O, 30/9/1).

L-Tr yp top h a n N-[(R)-1-In d a n yl]a m id e Hyd r och lor id e

Sa lt (3h ). Compound 3h was prepared by subjecting com-

pound 2h to general procedure E. Yield ) 100%.

N-BOC-^L-(4,4′-b ip h en yl)a la n in e

N-[(S)-Met h ylb en -

zyl]a m id e (2r r ). Compound 2r r was prepared by coupling

N-BOC-4,4′-biphenylalanine, 1j, with (S)-methylbenzylamine

according to general procedure D. Yield ) 78%. TLC: R_f)

0.90 (CHCl₃/MeOH/H₂O, 30/9/1).

N-BOC-^L-(4,4′-bip h en yl)a la n in e N-Ben zyla m id e (2ss).

Compound 2ss was prepared by coupling N-BOC-4,4′-biphe-

nylalanine, 1j, with benzylamine according to general proce-

dure D. Yield ) 84%. TLC: R_f) 0.90 (CHCl₃/MeOH/H₂O,

30/9/1).

N-BOC-^L-p h en yla la n in e N-Meth yla m id e (2tt). Com-

pound 2tt was prepared by coupling N-BOC-phenylalanine,

1k , with methylamine hydrochloride according to general

procedure D. Yield ) 76%. TLC: R_f) 0.70 (10% MeOH/

CHCl₃).

N-BOC-^L-(3-pyr idyl)alan in e N-Ben zylam ide (2u u ). Com-

pound 2u u was prepared by coupling N-BOC-3-pyridylalanine,

1l, with benzylamine according to general procedure D. Yield

) 68%. TLC: R_f) 0.64 (10% MeOH/CHCl₃).

N-BOC-^L-(4-pyr idyl)alan in e N-Meth ylam ide (2vv). Com-

pound 2vv was prepared by coupling N-BOC-4-pyridylalanine,

1m , with methylamine hydrochloride according to general

procedure D. Yield ) 71%. TLC: R_f) 0.12 (EtOAc).

N-BOC-^L-(4-p yr id yl)a la n in e N-[2-(4-Hyd r oxyp h en yl)-

eth yl]a m id e (2xx). Compound 2xx was prepared by coupling

N-BOC-4-pyridylalanine, 1m , with tyramine according to

general procedure D. Yield ) 84%. TLC: R_f) 0.30 (10%

MeOH/CHCl₃).

L-Tr yptoph an [(1R,2S)-2-Hydr oxy-1-in dan yl]am ide Hy-

d r och lor id e Sa lt (3i). Compound 3i was prepared by

subjecting compound 2i to general procedure E. Yield ) 100%.

L-Tr yptoph an [(1S,2R)-2-Hydr oxy-1-in dan yl]am ide Hy-

d r och lor id e Sa lt (3j). Compound 3j was prepared by

subjecting compound 2j to general procedure E. Yield ) 100%.

L-Tr yptoph an N-Ben zylam ide Hydr och lor ide Salt (3k).

Compound 3k was prepared by subjecting compound 2k to

general procedure E. Yield ) 100%.

L-Tr yp top h a n N-[(S)-Meth ylben zyl]a m id e Hyd r och lo-

r id e Sa lt (3l). Compound 3l was prepared by subjecting

compound 2l to general procedure E. Yield ) 100%.

L-Tr yp t op h a n P ip er on yla m id e H yd r och lor id e Sa lt

(3m ). Compound 3m was prepared by subjecting compound

2m to general procedure E. Yield ) 100%.

L-Tr yp top h a n N-(4-P yr id ylm eth yl)a m id e Hyd r och lo-

r id e Sa lt (3n ). Compound 3n was prepared by subjecting

compound 2n to general procedure E. Yield ) 100%.

L-Tr yp top h a n N-(3-P yr id ylm eth yl)a m id e Hyd r och lo-

r id e Sa lt (3o). Compound 3o was prepared by subjecting

compound 2o to general procedure E. Yield ) 100%.

L-Tr yp top h a n N-(2-P yr id ylm eth yl)a m id e Hyd r och lo-

r id e Sa lt (3p ). Compound 3p was prepared by subjecting

compound 2p to general procedure E. Yield ) 100%.

L-Tr yp top h a n N-[2-(2-P yr id yl)eth yl]a m id e Hyd r och lo-

r id e Sa lt (3q). Compound 3q was prepared by subjecting

compound 2q to general procedure E. Yield ) 100%.

L-Tr yp top h a n N-[2-(4-Hyd r oxyp h en yl)eth yl]a m id e Hy-

d r och lor id e Sa lt (3r ). Compound 3r was prepared by

subjecting compound 2r to general procedure E. Yield ) 100%.

L-Tr yp top h a n F u r fu r yla m id e Hyd r och lor id e Sa lt (3s).

Compound 3s was prepared by subjecting compound 2s to

general procedure E. Yield ) 100%.

L-Tr yptop h a n N-(2-Th ia zolylm eth yl)a m ide Hyd r och lo-

r id e Sa lt (3t). Compound 3t was prepared by subjecting

compound 2t to general procedure E. Yield ) 100%.

L-Tr yp top h a n N-(2-Ben zim id a zolylm eth yl)a m id e Hy-

d r och lor id e Sa lt (3u ). Compound 3u was prepared by

subjecting compound 2u to general procedure E. Yield )

100%.

N-BOC-^L-(4-p yr id yl)a la n in e

N-[(S)-Met h ylb en zyl]-

a m id e (2yy). Compound 2yy was prepared by coupling

N-BOC-4-pyridylalanine, 1m , with (S)-methylbenzylamine

according to general procedure D. Yield ) 75%. TLC: R_f)

0.47 (10% MeOH/CHCl₃).

N-BOC-^L-(4-pyr idyl)alan in e N-Ben zylam ide (2zz). Com-

pound 2zz was prepared by coupling N-BOC-4-pyridylalanine,

1m , with benzylamine according to general procedure D. Yield

) 56%. TLC: R_f) 0.57 (10% MeOH/CHCl₃).

N-BOC-^L-ter t-leu cin e N-Met h yla m id e (2a a a ). Com-

pound 2a a a was prepared by coupling N-BOC-tert-leucine, 1n ,

with methylamine hydrochloride according to general proce-

dure D. Yield ) 60%. TLC: R_f) 0.42 (50% EtOAc/hexane).

N-BOC-^L-a b r in e N-Met h yla m id e (2b b b ). Compound

2b b b was prepared by coupling N-BOC-^L-abrine, 1o, with

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 213

L-Tr yp t op h a n N-[3-(1-Im id a zolylp r op yl)]a m id e H y-

d r och lor id e Sa lt (3v). Compound 3v was prepared by

subjecting compound 2v to general procedure E. Yield )

100%.

L-Tr yp top h a n N-[3-(4-Mor p h olin ylp r op yl)]a m id e Hy-

d r och lor id e Sa lt (3w ). Compound 3w was prepared by

subjecting compound 2w to general procedure E. Yield )

100%.

L-Tr yp top h a n N,N-Dim eth yla m id e Hyd r och lor id e Sa lt

(3x). Compound 3x was prepared by subjecting compound 2x

to general procedure E. Yield ) 100%.

L-Tr yp top h a n P yr olid in yla m id e Hyd r och lor id e Sa lt

(3y). Compound 3y was prepared by subjecting compound 2y

to general procedure E. Yield ) 100%.

L-Tr yp top h a n P ip er id in yla m id e Hyd r och lor id e Sa lt

(3z). Compound 3z was prepared by subjecting compound 2z

to general procedure E. Yield ) 100%.

L-Tr yp top h a n Mor p h olin yla m id e Hyd r och lor id e Sa lt

(3a a ). Compound 3a a was prepared by subjecting compound

2a a to general procedure E. Yield ) 100%.

D-Tr yp t op h a n N-Met h yla m id e H yd r och lor id e Sa lt

(3bb). Compound 3bb was prepared by subjecting compound

2bb to general procedure E. Yield ) 100%.

L-[3-(1-Meth ylin d olyl)]a la n in e N-Meth yla m id e Hyd r o-

ch lor id e Sa lt (3cc). Compound 3cc was prepared by subject-

ing compound 2cc to general procedure E. Yield ) 100%.

L-(3-Ben zoth ien yl)a la n in e N-Meth yla m id e Hyd r och lo-

r id e Sa lt (3d d ). Compound 3d d was prepared by subjecting

compound 2d d to general procedure E. Yield ) 100%.

L-(1-Na p h th yl)a la n in e N-Meth yla m id e Hyd r och lor id e

Sa lt (3ee). Compound 3ee was prepared by subjecting

compound 2ee to general procedure E. Yield ) 100%.

L-(1-Na p h t h yl)a la n in e N-[3-(4-Mor p h olin ylp r op yl)]-

a m id e Hyd r och lor id e Sa lt (3ff). Compound 3ff was pre-

pared by subjecting compound 2ff to general procedure E.

Yield ) 100%.

L-(2-Na p h th yl)a la n in e N-Meth yla m id e Hyd r och lor id e

Sa lt (3gg). Compound 3gg was prepared by subjecting

compound 2gg to general procedure E. Yield ) 100%.

L-(2-Na p h t h yl)a la n in e N-[3-(4-Mor p h olin ylp r op yl)]-

a m id e Hyd r och lor id e Sa lt (3h h ). Compound 3h h was

prepared by subjecting compound 2h h to general procedure

E. Yield ) 100%. TLC: R_f) 0.63 (CHCl₃/MeOH/H₂O, 30/9/

1).

L-(2-Na p h th yl)a la n in e N-[2-(4-Hyd r oxyp h en yl)eth yl]-

a m id e Hyd r och lor id e Sa lt (3ii). Compound 3ii was pre-

pared by subjecting compound 2ii to general procedure E. Yield

) 100%. TLC: R_f) 0.61 (CHCl₃/MeOH/H₂O, 30/9/1).

L-(2-Na p h th yl)a la n in e N-[(S)-Meth ylben zyl]a m id e Hy-

d r och lor id e Sa lt (3jj). Compound 3jj was prepared by

subjecting compound 2jj to general procedure E. Yield )

100%. TLC: R_f) 0.51 (10% MeOH/CHCl₃).

L-(2-Na p h th yl)a la n in e N-Ben zyla m id e Hyd r och lor id e

Sa lt (3k k ). Compound 3k k was prepared by subjecting

compound 2k k to general procedure E. Yield ) 100%. TLC:

R_f) 0.60 (10% MeOH/CHCl₃).

L-(3-Qu in olyl)a la n in e N-Meth yla m id e Hyd r och lor id e

Sa lt (3ll). Compound 3ll was prepared by subjecting com-

pound 2ll to general procedure E. Yield ) 100%. TLC: R_f)

0.40 (10% MeOH/CHCl₃).

L-(8-Qu in olyl)alan in e Meth ylam ide Hydr och lor ide Salt

(3m m ). Compound 3m m was prepared by subjecting com-

pound 2m m to general procedure E. Yield ) 100%. TLC: R_f

) 0.41 (10% MeOH/CHCl₃).

L-(4,4′-Bip h en yl)a la n in e N-Meth yla m id e Hyd r och lo-

r id e Sa lt (3oo). Compound 3oo was prepared by subjecting

compound 2oo to general procedure E. Yield ) 100%.

L-(4,4′-Bip h en yl)a la n in e N-[3-(4-Mor p h olin ylp r op yl)]-

a m id e Hyd r och lor id e Sa lt (3p p ). Compound 3p p was

prepared by subjecting compound 2p p to general procedure

E. Yield ) 100%. TLC: R_f) 0.61 (CHCl₃/MeOH/H₂O, 30/9/

1).

prepared by subjecting compound 2qq to general procedure

E. Yield ) 100%. TLC: R_f) 0.65 (CHCl₃/MeOH/H₂O, 30/9/

1).

L-(4,4′-Biph en yl)alan in e N-[(S)-Meth ylben zyl]am ide Hy-

d r och lor id e Sa lt (3r r ). Compound 3r r was prepared by

subjecting compound 2r r to general procedure E. Yield )

100%. TLC: R_f) 0.65 (CHCl₃/MeOH/H₂O, 30/9/1).

L-(4,4′-Bip h en yl)a la n in e N-Ben zyla m id e Hyd r och lo-

r id e Sa lt (3ss). Compound 3ss was prepared by subjecting

compound 2ss to general procedure E. Yield ) 100%. TLC:

R_f) 0.59 (10% MeOH/CHCl₃).

L-P h en yla la n in e N-Meth yla m id e Hyd r och lor id e Sa lt

(3tt). Compound 3tt was prepared by subjecting compound

2tt to general procedure E. Yield ) 100%. TLC: R_f) 0.38

(10% MeOH/CHCl₃).

L-(3-P yr id yl)a la n in e N-Ben zyla m id e Hyd r och lor id e

Sa lt (3u u ). Compound 3u u was prepared by subjecting

compound 2u u to general procedure E. Yield ) 100%. TLC:

R_f) 0.24 (10% MeOH/CHCl₃).

L-(4-P yr id yl)a la n in e N-Meth yla m id e Hyd r och lor id e

Sa lt (3vv). Compound 3vv was prepared by subjecting

compound 2vv to general procedure E. Yield ) 100%.

L-(4-P yr id yl)a la n in e N-[2-(4-H yd r oxyp h en yl)et h yl]-

a m id e Hyd r och lor id e Sa lt (3xx). Compound 3xx was

prepared by subjecting compound 2xx to general procedure

E. Yield ) 100%.

L-(4-P yr id yl)a la n in e N-[(S)-Meth ylben zyl]a m id e Hy-

d r och lor id e Sa lt (3yy). Compound 3yy was prepared by

subjecting compound 2yy to general procedure E. Yield )

100%.

L-(4-P yr id yl)a la n in e N-Ben zyla m id e Hyd r och lor id e

Sa lt (3zz). Compound 3zz was prepared by subjecting

compound 2zz to general procedure E. Yield ) 100%. TLC:

R_f) 0.44 (CHCl₃/MeOH/H₂O, 30/9/1).

L-ter t-Leu cin e N-Met h yla m id e H yd r och lor id e Sa lt

(3a a a ). Compound 3a a a was prepared by subjecting com-

pound 2a a a to general procedure E. Yield ) 100%.

L-Abr in e N-Meth yla m id e Hyd r och lor id e Sa lt (3bbb).

Compound 3bbb was prepared by subjecting compound 2bbb

to general procedure E. Yield ) 100%.

L-Ab r in e N-[3-(4-Mor p h olin ylp r op yl)]a m id e H yd r o-

ch lor id e Sa lt, 3ccc. Compound 3ccc was prepared by

subjecting compound 2ccc to general procedure E. Yield

(100)%.

(R)-2-(2-Meth ylp r op yl)-3-(ter t-bu toxyca r bon yl)p r op i-

on ic Acid (4c). Compound 4c was prepared by subjecting

compound 15a to general procedure C. Yield ) 68%.

(R)-2-Bu tyl-3-(ter t-bu toxycar bon yl)pr opion ic Acid (4d).

Compound 4d was prepared by subjecting compound 15b to

general procedure C. Yield ) 76%.

(R)-2-Hexyl-3-(ter t-bu toxycar bon yl)pr opion ic Acid (4e).

Compound 4e was prepared by subjecting compound 15c to

general procedure C. Yield ) 46%.

(R)-2-Octyl-3-(ter t-bu toxyca r bon yl)p r op ion ic Acid (4f).

Compound 4f was prepared by subjecting compound 15d to

general procedure C. Yield ) 76%.

(R)-2-(Isop r op yloxy)-3-(m et h oxyca r b on yl)p r op ion ic

Acid (4g). 10% Pd/C (0.48 g) was placed under vacuum, and

MeOH (5 mL) was added. Compound 21a (1.92 g, 6.86 mmol)

was dissolved in MeOH (10 mL) and added, via cannula, to

the Pd/C. The mixture was degassed under vacuum and

stirred under H₂for 16 h. Filtration of the reaction through

Celite and concentration under vacuum gave the desired

product (1.30 g, 100%) which was used without further

purification. TLC: R_f) 0.10 (15% EtOAc/hexane).

(R)-2-(P en tyloxy)-3-(m eth oxyca r bon yl)p r op ion ic Acid

(4h ). 10% Pd/C (0.35 g) was placed under vacuum, and MeOH

(10 mL) was added. The ether (1.40 g, 4.55 mmol) was

dissolved in MeOH (5 mL) and added, via cannula, to the Pd/

C. The mixture was degassed under vacuum and stirred under

H₂for 24 h. Filtration of the reaction through Celite and

concentration under vacuum gave compound 4h (0.98 g, 100%),

which was used without further purification.

L-(4,4′-Bip h en yl)a la n in e N-[2-(4-Hyd r oxyp h en yl)eth yl]-

a m id e Hyd r och lor id e Sa lt (3qq). Compound 3qq was

214 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Levy et al.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-L-tr yp -

top h a n N-1-P en tyla m id e (5b). Compound 5b was prepared

by coupling compound 3b with compound 4a according to

general procedure F. Yield ) 67%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n F u r fu r yla m id e (5s). Compound 5s was prepared

by coupling compound 3s with compound 4a according to

general procedure F. Yield ) 55%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n (Hyd r oxyeth yl)a m id e (5c). Compound 5c was

prepared by coupling compound 3c with compound 4a accord-

ing to general procedure F. Yield ) 14%. TLC: R_f) 0.0.58

(10% MeOH/CHCl₃).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-(2-Th ia zolylm eth yl)a m id e (5t). Compound 5t

was prepared by coupling compound 3t with compound 4a

according to general procedure F. Yield ) 45%. TLC: R_f)

0.36 (70% EtOAc/hexane).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

t op h a n N-[2-(Ca r b ob en zyloxya m in o)et h yl]a m id e (5d ).

Compound 5d was prepared by coupling compound 3d with

compound 4a according to general procedure F. Yield ) 40%.

TLC: R_f) 0.67 (MeOH/CHCl₃, 1/25).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-Cyclop r op yla m id e (5e). Compound 5e was

prepared by coupling compound 3e with compound 4a accord-

ing to general procedure F. Yield ) 79%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-Cyclop en tyla m id e (5f). Compound 5f was pre-

pared by coupling compound 3f with compound 4a according

to general procedure F. Yield ) 58%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-(2-Ben zim id a zolylm eth yl)a m id e (5u ). Com-

pound 5u was prepared by coupling compound 3u with

compound 4a according to general procedure F. Yield ) 71%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-[3-(1-Im id a zolylp r op yl)]a m id e (5v). Compound

5v was prepared by coupling compound 3v with compound 4a

according to general procedure F. Yield ) 58%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-[3-(4-Mor p h olin ylp r op yl)]a m id e (5w ). Com-

pound 5w was prepared by coupling compound 3w with

compound 4a according to general procedure F. Yield ) 50%.

TLC: R_f) 0.55 (15% MeOH/CHCl₃).

3-(Met h oxyca r bon yl-2(R)-(isob u t ylp r op ion yl)-^L-t r yp -

top h a n N-[(S)-1-In d a n yl]a m id e (5g). Compound 5g was

prepared by coupling compound 3g with compound 4a accord-

ing to general procedure F. Yield ) 48%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-L-tr yp -

top h a n N,N-Dim eth yla m id e (5x). Compound 5x was pre-

pared by coupling compound 3x with compound 4a according

to general procedure F. Yield ) 69%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-[(R)-1-In d a n yl]a m id e (5h ). Compound 5h was

prepared by coupling compound 3h with compound 4a accord-

ing to general procedure F. Yield ) 44%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n P yr olid in yla m id e (5y). Compound 5y was prepared

by coupling compound 3y with compound 4a according to

general procedure F. Yield ) 57%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n [(1R,2S)-2-Hyd r oxy-1-in d a n yl]a m id e (5i). Com-

pound 5i was prepared by coupling compound 3i with com-

pound 4a according to general procedure F. Yield ) 56%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n [(1S,2R)-2-Hyd r oxy-1-in d a n yl]a m id e (5j). Com-

pound 5j was prepared by coupling compound 3j with com-

pound 4a according to general procedure F. Yield ) 72%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-Ben zyla m id e (5k ). Compound 5k was prepared

by coupling compound 3k with compound 4a according to

general procedure F. Yield ) 83%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-[(S)-Meth ylben zyl]a m id e (5l). Compound 5l was

prepared by coupling compound 3l with compound 4a accord-

ing to general procedure F. Yield ) 50%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n P ip er on yla m id e (5m ). Compound 5m was prepared

by coupling compound 3m with compound 4a according to

general procedure F. Yield ) 77%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n P ip er id in yla m id e (5z). Compound 5z was prepared

by coupling compound 3z with compound 4a according to

general procedure F. Yield ) 85%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n Mor p h olin yla m id e (5a a ). Compound 5a a was

prepared by coupling compound 3a a with compound 4a

according to general procedure F. Yield ) 78%. TLC: R_f)

0.41 (EtOAc).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^D-tr yp -

top h a n Meth yla m id e (5bb). Compound 5bb was prepared

by coupling compound 3bb with compound 4a according to

general procedure F. Yield ) 57%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-[3-(1-

Meth ylin d olyl)]a la n in e N-Meth yla m id e (5cc). Compound

5cc was prepared by coupling compound 3cc with compound

4a according to general procedure F. Separation of the

diastereomers due to racemic 1c was accomplished via column

chromatography (silica gel, EtOAc/hexane, 2/1). Yield ) 36%.

TLC: R_f) 0.36 (EtOAc/hexane, 2/1).

3-(Meth oxycar bon yl)-2(R)-(isobu tylpr opion yl)-^L-(3-ben -

zoth ien yl)a la n in e N-Meth yla m id e (5d d ). Compound 5d d

was prepared by coupling compound 3d d with compound 4a

according to general procedure F. Yield ) 84%. TLC: R_f)

0.20 (50% EtOAc/hexane).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-(4-P yr id ylm eth yl)a m id e (5n ). Compound 5n

was prepared by coupling compound 3n with compound 4a

according to general procedure F. Yield ) 44%. TLC: R_f)

0.15 (EtOAc).

3-(Met h oxyca r b on yl)-2(R)-(isob u t ylp r op ion yl)-^L-(1-

n a p h th yl)a la n in e N-Meth yla m id e (5ee). Compound 5ee

was prepared by coupling compound 3ee with compound 4a

according to general procedure F. Yield ) 76%. TLC: R_f)

0.29 (50% EtOAc/hexane).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-(3-P yr id ylm eth yl)a m id e (5o). Compound 5o was

prepared by coupling compound 3o with compound 4a accord-

ing to general procedure F. Yield ) 58%. TLC: R_f) 0.17

(EtOAc).

3-(Met h oxyca r b on yl)-2(R)-(isob u t ylp r op ion yl)-^L-(1-

n aph th yl)alan in e N-[3-(4-Mor ph olin ylpr opyl)]am ide (5ff).

Compound 5ff was prepared by coupling compound 3ff with

compound 4a according to general procedure F. Yield ) 30%.

TLC: R_f) 0.60 (10% MeOH/CHCl₃).

3-(Met h oxyca r b on yl)-2(R)-(isob u t ylp r op ion yl)-^L-(2-

n a p h th yl)a la n in e N-Meth yla m id e (5gg). Compound 5gg

was prepared by coupling compound 3gg with compound 4a

according to general procedure F. Yield ) 66%. TLC: R_f)

0.75 (10% MeOH/CHCl₃).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-(2-P yr id ylm eth yl)a m id e (5p ). Compound 5p

was prepared by coupling compound 3p with compound 4a

according to general procedure F. Yield ) 70%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-[2-(2-P yr id yl)eth yl]a m id e (5q). Compound 5q

was prepared by coupling compound 3q with compound 4a

according to general procedure F. Yield ) 49%.

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-[2-(4-Hyd r oxyp h en yl)eth yl]a m id e (5r ). Com-

pound 5r was prepared by coupling compound 3r with

compound 4a according to general procedure F. Yield ) 40%.

TLC: R_f) 0.11 (50% EtOAc/hexane).

3-(Met h oxyca r b on yl)-2(R)-(isob u t ylp r op ion yl)-^L-(2-

n a p h t h yl)a la n in e N-[3-(4-Mor p h olin ylp r op yl)]a m id e

(5h h ). Compound 5h h was prepared by coupling compound

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 215

3h h with compound 4a according to general procedure F.

Yield ) 66%. TLC: R_f) 0.56 (20% MeOH/CHCl₃).

3-(Met h oxyca r b on yl)-2(R)-(isob u t ylp r op ion yl)-^L-(2-

n a p h t h yl)a la n in e N-[2-(4-Hyd r oxyp h en yl)et h yl]a m id e

(5ii). Compound 5ii was prepared by coupling compound 3ii

with compound 4a according to general procedure F. Yield )

69%. TLC: R_f) 0.61 (10% MeOH/CHCl₃).

3-(Met h oxyca r b on yl)-2(R)-(isob u t ylp r op ion yl)-^L-(2-

n a p h th yl)a la n in e N-[(S)-Meth ylben zyl]a m id e (5jj). Com-

pound 5jj was prepared by coupling compound 3jj with

compound 4a according to general procedure F. Yield ) 53%.

TLC: R_f) 0.38 (EtOAc/hexane, 1/2).

3-(Met h oxyca r b on yl)-2(R)-(isob u t ylp r op ion yl)-^L-(2-

n a p h th yl)a la n in e N-Ben zyla m id e (5k k ). Compound 5k k

was prepared by coupling compound 3k k with compound 4a

according to general procedure F. Yield ) 85%. TLC: R_f)

0.50 (10% MeOH/CHCl₃).

3-(Met h oxyca r b on yl)-2(R)-(isob u t ylp r op ion yl)-^L-(3-

qu in olyl)a la n in e N-Meth yla m id e (5ll). Compound 5ll was

prepared by coupling compound 3ll with compound 4a accord-

ing to general procedure F. Yield ) 96%. TLC: R_f) 0.44

(MeOH/CHCl₃, 1/20).

3-(Met h oxyca r b on yl)-2(R)-(isob u t ylp r op ion yl)-^L-(8-

qu in olyl)a la n in e Meth yla m id e (5m m ). Compound 5m m

was prepared by coupling compound 3m m with compound 4a

according to general procedure F. Yield ) 69%. TLC: R_f)

0.44 (10% MeOH/CHCl₃).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(4,4′-

bip h en yl)a la n in e N-Meth yla m id e (5oo). Compound 5oo

was prepared by coupling compound 3oo with compound 4a

according to general procedure F. Yield ) 63%. TLC: R_f)

0.58 (MeOH/CHCl₃, 1/50).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(4,4′-

biph en yl)alan in e N-[3-(4-Mor ph olin ylpr opyl)]am ide (5pp).

Compound 5p p was prepared by coupling compound 3p p with

compound 4a according to general procedure F. Yield ) 50%.

TLC: R_f) 0.38 (MeOH/CHCl₃, 1/5).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(4,4′-

b ip h en yl)a la n in e N-[2-(4-H yd r oxyp h en yl)et h yl]a m id e

(5qq). Compound 5qq was prepared by coupling compound

3qq with compound 4a according to general procedure F.

Yield ) 77%. TLC: R_f) 0.53 (20% MeOH/CHCl₃).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(4,4′-

bip h en yl)a la n in e N-[(S)-Meth ylben zyl]a m id e (5r r ). Com-

pound 5r r was prepared by coupling compound 3r r with

compound 4a according to general procedure F. Yield ) 51%.

TLC: R_f) 0.50 (EtOAc/hexane, 2/1).

pound 5yy was prepared by coupling compound 3yy with

compound 4a according to general procedure F. Yield ) 86%.

TLC: R_f) 0.37 (MeOH/CHCl₃, 1/5).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(4-p y-

r id yl)a la n in e N-Ben zyla m id e (5zz). Compound 5zz was

prepared by coupling compound 3zz with compound 4a ac-

cording to general procedure F. Yield ) 53%. TLC: R_f) 0.43

(MeOH/CHCl₃, 1/5).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-ter t-

leu cin e N-Meth yla m id e (5a a a ). Compound 5a a a was pre-

pared by coupling compound 3a a a with compound 4a accord-

ing to general procedure F. Yield ) 57%. TLC: R_f) 0.54

(EtOAc).

3-(Me t h o x y c a r b o n y l)-2(R )-(is o b u t y lp r o p io n y l)-^L-

a br in e N-Meth yla m id e (5bbb). Compound 4a (0.46 g, 2.45

mmol) was dissolved in dry THF (5 mL), and oxalyl chloride

(0.21 mL, 2.45 mmol) was added followed by the addition of

DMF (1 drop). The reaction mixture was stirred for 20 min

at room temperature, after which compound 3bbb (0.65 g, 2.45

mmol) was added followed by triethylamine (1.19 mL, 8.56

mmol). The reaction mixture was stirred at room temperature

for an additional 24 h and quenched with the addition of water

(10 mL). The mixture was washed with EtOAc (30 mL), and

the organic phase was sequentially washed with 1 N HCl (3

× 10 mL), saturated NaHCO₃(3 × 10 mL), and brine (10 mL).

After being dried over anhydrous MgSO₄, the organic phase

was concentrated, and the residue was purified on silica gel

(50% EtOAc/hexane), giving compound 5bbb (0.84 g, 86%).

TLC: R_f) 0.45 (EtOAc).

3-(Me t h o x y c a r b o n y l)-2(R )-(is o b u t y lp r o p io n y l)-^L-

a br in e N-[3-(4-Mor p h olin ylp r op yl)]a m id e (5ccc). Com-

pound 5ccc was prepared by coupling compound 3ccc with

compound 4a according to the procedure utilized for the

preparation of compound 5bbb. Yield ) 80%. TLC: R_f) 0.40

(10% MeOH/CHCl₃).

3-(Meth oxyca r bon yl)-2(S)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-Meth yla m id e (5d d d ). Compound 5d d d was

prepared by coupling compound 3a with compound 4b accord-

ing to general procedure F. Yield ) 53%.

3-(ter t-Bu toxycar bon yl)-2(R)-(isobu tylpr opion yl)-^L-tr yp-

top h a n N-Meth yla m id e (5eee). Compound 5eee was pre-

pared by coupling compound 3a with compound 4c according

to general procedure F. Yield ) 48%.

3-(ter t-Bu toxyca r bon yl)-2(R)-(bu tylp r op ion yl)-^L-tr yp -

top h a n N-Meth yla m id e (5fff). Compound 5fff was prepared

by coupling compound 3a with compound 4d according to

general procedure F. Yield ) 47%. TLC: R_f) 0.15 (50%

EtOAc/hexane).

3-(Me t h oxyca r b on yl)-2(R )-(b u t ylp r op ion yl)-^L-t r yp -

top h a n N-Meth yla m id e (5ggg). Compound 5ggg was pre-

pared by subjecting compound 7eee to general procedure J

(solvent ) MeOH). Yield ) 92%. TLC: R_f) 0.40 (EtOAc).

3-(ter t-Bu toxyca r bon yl)-2(R)-(h exylp r op ion yl)-^L-tr yp -

top h a n N-Meth yla m id e (5h h h ). Compound 5h h h was

prepared by coupling compound 3a with compound 4e accord-

ing to general procedure F. Yield ) 26%. TLC: R_f) 0.18

(50% EtOAc/hexane).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(4,4′-

bip h en yl)a la n in e N-Ben zyla m id e (5ss). Compound 5ss

was prepared by coupling compound 3ss with compound 4a

according to general procedure F. Yield ) 54%. TLC: R_f)

0.36 (10% MeOH/CHCl₃).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-p h e-

n yla la n in e N-Meth yla m id e (5tt). Compound 5tt was pre-

pared by coupling compound 3tt with compound 4a according

to general procedure F. Yield ) 65%. TLC: R_f) 0.71 (MeOH/

CHCl₃, 1/5).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(3-p y-

r id yl)a la n in e N-Ben zyla m id e (5u u ). Compound 5u u was

prepared by coupling compound 3u u with compound 4a

according to general procedure F. Yield ) 73%. TLC: R_f)

0.61 (MeOH/CHCl₃, 1/5).

3-(Me t h oxyca r b on yl)-2(R )-(h e xylp r op ion yl)-^L-t r yp -

top h a n N-Meth yla m id e (5iii). Compound 5iii was prepared

by subjecting compound 7fff to general procedure J (solvent

) MeOH). Yield ) 95%. TLC: R_f) 0.45 (EtOAc).

3-(ter t-Bu toxyca r bon yl)-2(R)-(octylp r op ion yl)-^L-tr yp -

top h a n N-Meth yla m id e (5jjj). Compound 5jjj was prepared

by coupling compound 3a with compound 4f according to

general procedure F. Yield ) 38%. TLC: R_f) 0.20 (50%

EtOAc/hexane).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(4-p y-

r id yl)a la n in e N-Meth yla m id e (5vv). Compound 5vv was

prepared by coupling compound 3vv with compound 4a

according to general procedure F. Yield ) 74%. TLC: R_f)

0.30 (5% MeOH/CHCl₃).

3-(Me t h oxyca r b on yl)-2(R )-(oct ylp r op ion yl)-^L-t r yp -

top h a n N-Meth yla m id e (5k k k ). Compound 5k k k was

prepared by subjecting compound 7ggg to general procedure

J (solvent ) MeOH). Yield ) 96%. TLC: R_f) 0.50 (EtOAc).

3-(Meth oxyca r bon yl)-2(R)-[(isop r op yloxy)p r op ion yl]-

L-tr yp top h a n Meth yla m id e (5lll). Compound 5lll was

prepared by subjecting coupling compound 4g with compound

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(4-p y-

r id yl)a la n in e N-[2-(4-Hyd r oxyp h en yl)eth yl]a m id e (5xx).

Compound 5xx was prepared by coupling compound 3xx with

compound 4a according to general procedure F. Yield ) 56%.

TLC: R_f) 0.49 (10% MeOH/CHCl₃).

3-(Meth oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-(4-p y-

r id yl)a la n in e N-[(S)-Met h ylb en zyl]a m id e (5yy). Com-

216 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Levy et al.

3a according to general procedure F. Yield ) 40%. TLC: R_f

) 0.31 (EtOAc).

3-(Met h oxyca r b on yl)-2(R)-[(p en t yloxy)p r op ion yl]-^L-

tr yp top h a n Meth yla m id e (5m m m ). Compound 5m m m

was prepared by coupling compound 4h with compound 3a

according to general procedure F. Yield ) 42%. TLC: R_f)

0.35 (EtOAc).

3-(Meth oxyca r bon yl)-3(S)-h yd r oxy-2(R)-(isobu tylp r o-

p ion yl)-^L-tr yp top h a n N-Meth yla m id e (5n n n ). Compound

5n n n was prepared by subjecting compound 7e to general

procedure J (solvent ) MeOH). Yield ) 71%. TLC: R_f) 0.22

(EtOAc).

3-(Meth oxyca r bon yl)-3(S)-h yd r oxy-2(R)-(isobu tylp r o-

p ion yl)-^L-ter t-leu cin e N-Meth yla m id e (5ooo). Compound

5ooo was prepared by subjecting compound 7f to general

procedure J (solvent ) MeOH). Yield ) 93%. TLC: R_f) 0.39

(EtOAc).

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-(1-P en tyl)a m id e (6b). Compound 6b was

prepared by subjecting compound 5b to general procedure G.

Yield ) 41%. Purity: >98% (HPLC method C). ¹H NMR (300

MHz, DMSO): δ 0.8 (t, 3H), 0.9 (dd, 6H), 1.1-1.4 (m, 9H), 1.9

(dd, 1H), 2.0 (dd, 1H), 2.7 (m, 1H), 3.0 (m, 3H), 3.1 (dd, 1H),

4.5 (m, 1H), 6.95 (t, 1H), 7.05 (t, 1H), 7.1 (s, 1H), 7.3 (d, 1H),

7.5 (d, 1H), 7.7 (t, 1H), 8.0 (d, 1H), 8.7 (s, 1H), 10.4 (s, 1H),

10.8 (s, 1H). Anal. (C₂₄H₃₆N₄O₄) H, N; C: calcd, 64.84; found,

65.25.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n (Hyd r oxyeth yl)a m id e (6c). Compound 6c was

prepared by subjecting compound 5c to general procedure G.

Yield ) 18%. TLC: R_f) 0.57 (CHCl₃/MeOH/H₂O, 45/9/1).

Purity: >98% (HPLC method B). ¹H NMR (300 MHz,

DMSO): δ 0.75 (dd, 6H), 0.95 (m, 1H), 1.35 (m, 2H), 1.9 (dd,

1H), 2.0 (dd, 1H), 2.65 (m, 1H), 2.95 (dd, 1H), 3.1 (m, 3H), 3.3

(m, 2H), 4.45 (m, 1H), 4.6 (t, 1H), 6.95 (t, 1H), 7.0 (t, 1H), 7.1

(s, 1H), 7.3 (d, 1H), 7.55 (d, 1H), 7.75 (m, 1H), 8.05 (d, 1H),

8.85 (s, 1H), 10.4 (s, 1H), 11.75 (s, 1H). Anal. (C₂₁H₃₀N₄O₅)

C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yptoph an N-[2-(Car boben zyloxyam in o)eth yl]am ide (6d).

Compound 6d was prepared by subjecting compound 5d to

general procedure G. Yield ) 30%. TLC: R_f) 0.48 (MeOH/

CHCl₃, 1/6). Purity: >92% (HPLC method A). ¹H NMR (300

MHz, DMSO): δ 0.75 (dd, 6H), 1.0 (m, 1H), 1.35 (m, 2H), 1.9

(dd, 1H), 2.05 (dd, 1H), 2.65 (m, 1H), 2.9-3.2 (m, 6H), 4.4 (m,

1H), 5.0 (s, 2H), 7.0 (t, 1H), 7.1 (t, 1H), 7.15 (s, 1H), 7.2 (m,

1H), 7.25-7.45 (m, 6H), 7.55 (d, 1H), 8.0 (m, 1H), 8.05 (d, 1H),

8.8 (bs, 1H), 10.4 (bs, 1H), 10.8 (s, 1H). Anal. (C₂₉H₃₇N₅O₆)

C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-Cyclop r op yla m id e (6e). Compound 6e was

prepared by subjecting compound 5e to general procedure G.

Yield ) 11%. Purity: >95% (HPLC method E). ¹H NMR (300

MHz, DMSO): δ 0.3 (m, 2H), 0.55 (m, 2H), 0.8 (dd, 6H), 1.0

(m, 1H), 1.35 (m, 2H), 1.95 (dd, 1H), 2.05 (dd, 1H), 2.6 (m, 1H),

2.65 (m, 1H), 2.95 (dd, 1H), 3.1 (dd, 1H), 4.4 (m, 1H), 6.95 (t,

1H), 7.05 (t, 1H), 7.1 (s, 1H), 7.3 (d, 1H), 7.55 (d, 1H), 7.85 (d,

1H), 7.95 (d, 1H), 8.75 (s, 1H), 10.4 (s, 1H), 10.8 (s, 1H). Anal.

(C₂₂H₃₀N₄O₄) C, H, N.

1.7 (m, 1H), 1.95 (m, 2H), 2.3 (m, 1H), 2.7-2.9 (m, 3H), 3.0

(dd, 1H), 3.15 (dd, 1H), 4.95 (m, 1H), 5.2 (m, 1H), 6.75 (d, 1H),

6.95 (t, 1H), 7.05 (t, 2H), 7.2 (m, 3H), 7.35 (d, 1H), 7.6 (d, 1H),

8.0 (d, 1H), 8.05 (d, 1H), 8.7 (s, 1H), 10.35 (s, 1H), 10.8 (s, 1H).

Anal. (C₂₈H₃₄N₄O₄‚0.25H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-[(R)-1-In d a n yl]a m id e (6h ). Compound 6h

was prepared by subjecting compound 5h to general procedure

G. Yield ) 33%. Purity: >91% (HPLC method E). ¹H NMR

(300 MHz, DMSO): δ 0.8 (dd, 6H), 1.0 (m, 1H), 1.4 (m, 2H),

1.65 (m, 1H), 1.95 (m, 2H), 2.25 (m, 1H), 2.7-2.9 (m, 3H), 3.0

(dd, 1H), 3.15 (dd, 1H), 4.55 (m, 1H), 5.25 (m, 1H), 6.95 (t,

1H), 7.0-7.15 (m, 3H), 7.15-7.25 (m, 3H), 7.3 (d, 1H), 7.6 (d,

1H), 8.1 (m, 2H), 8.7 (s, 1H), 10.35 (s, 1H), 10.8 (s, 1H). Anal.

(C₂₈H₃₄N₄O₄) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yptoph an -[(1R,2S)-2-Hydr oxy-1-in dan yl]am ide (6i). Com-

pound 6i was prepared by subjecting compound 5i to general

procedure G. Yield ) 14%. Purity: >98% (HPLC method E).

¹H NMR (300 MHz, DMSO): δ 0.75 (dd, 6H), 1.0 (m, 1H), 1.4

(m, 2H), 1.9 (m, 2H), 2.75 (m, 2H), 3.05 (m, 2H), 3.25 (dd, 1H),

4.4 (m, 1H), 4.65 (m, 1H), 4.85 (d, 1H), 5.15 (m, 1H), 6.8 (d,

1H), 7.0 (t, 1H), 7.1 (m, 2H), 7.2 (m, 3H), 7.35 (d, 1H), 7.65 (d,

1H), 7.7 (d, 1H), 8.3 (d, 1H), 8.7 (s, 1H), 10.35 (s, 1H), 10.8 (s,

1H). Anal. (C₂₈H₃₄N₄O₅) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yptoph an -[(1S,2R)-2-Hydr oxy-1-in dan yl]am ide (6j). Com-

pound 6j was prepared by subjecting compound 5j to general

procedure G. Yield ) 20%. Purity: >98% (HPLC method C).

¹H NMR (300 MHz, DMSO): δ 0.8 (dd, 6H), 1.0 (m, 1H), 1.4

(m, 2H), 1.9 (m, 2H), 2.8 (m, 1H), 2.85 (dd, 1H), 3.0 (m, 2H),

3.3 (dd, 1H), 4.4 (m, 1H), 4.7 (m, 1H), 5.0 (d, 1H), 5.2 (m, 1H),

7.0 (t, 1H), 7.1-7.3 (m, 6H), 7.35 (d, 1H), 7.6 (dd, 2H), 8.4 (d,

1H), 8.7 (s, 1H), 10.4 (s, 1H), 10.8 (s, 1H). Anal.

(C₂₈H₃₄N₄O₅‚0.25H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-Ben zyla m id e (6k ). Compound 6k was pre-

pared by subjecting compound 5k to general procedure G. Yield

) 38%. Purity: >91% (HPLC method C). ¹H NMR (300 MHz,

DMSO): δ 0.8 (dd, 6H), 1.0 (m, 1H), 1.4 (m, 2H), 1.95 (dd, 1H),

2.0 (dd, 1H), 2.7 (m, 1H), 3.0 (dd, 1H), 3.15 (dd, 1H), 4.25 (m,

2H), 4.6 (m, 1H), 6.95 (t, 1H), 7,0 (t, 1H), 7,1 (m, 3H), 7.2 (m,

4H), 7.3 (d, 1H), 8.1 (d, 1H), 8.3 (t, 1H), 8.75 (s, 1H), 10.5 (s,

1H), 11.0 (s, 1H). Anal. (C₂₆H₃₂N₄O₄‚0.25H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-[(S)-Meth ylben zyl]a m id e (6l). Compound

6l was prepared by subjecting compound 5l to general proce-

dure G. Yield ) 20%. Purity: >99% (HPLC method A). ¹H

NMR (300 MHz, DMSO): δ 0.75 (dd, 6H), 1.0 (m, 1H), 1.3 (d,

3H), 1.3-1.45 (m, 2H), 1.9-2.1 (m, 2H), 2.7 (m, 1H), 2.95-

3.15 (m, 2H), 4.45-4.55 (m, 1H), 4.8-5.0 (m, 1H), 6.95 (t, 1H),

7.05 (t, 1H), 7.1-7.3 (m, 6H), 7.45 (d, 1H), 7.55 (d, 1H), 8.1 (d,

1H), 8.2 (d, 1H), 8.6-10.6 (broad signals, 2H), 10.85 (s, 1H).

Anal. (C₂₇H₃₄N₄O₄) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n P ip er on yla m id e (6m ). Compound 6m was

prepared by subjecting compound 5m to general procedure G.

Yield ) 10%. Purity: >95% (HPLC method E). ¹H NMR (300

MHz, DMSO): δ 0.75 (dd, 6H), 1.0 (m, 1H), 1.35 (m, 2H), 1.9

(dd, 1H), 2.05 (dd, 1H), 2.65 (m, 1H), 3.0 (dd, 1H), 3.15 (dd,

1H), 4.15 (m, 2H), 4.5 (m, 1H), 5.95 (s, 2H), 6.6 (d, 1H), 6.75

(t, 2H), 6.95 (t, 1H), 7.05 (t, 1H), 7.1 (s, 1H), 7.35 (d, 1H), 7.6

(d, 1H), 8.1 (d, 1H), 8.4 (t, 1H), 8.7-10.4 (broad signals, 2H),

10.8 (s, 1H). Anal. (C₂₇H₃₂N₄O₆‚0.25H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-(4-P yr id ylm eth yl)a m id e (6n ). Compound

6n was prepared by subjecting compound 5n to general

procedure G. Yield ) 45%. TLC: R_f) 0.60 (CHCl₃/MeOH/

H₂O, 100/45/5). Purity: >90% (HPLC method A). ¹H NMR

(300 MHz, DMSO): δ 0.8 (dd, 6H), 1.15 (m, 1H), 1.5 (m, 2H),

2.1 (dd, 1H), 2.25 (dd, 1H), 2.85 (m, 1H), 3.15 (dd, 1H), 3.3

(dd, 1H), 4.35 (d, 2H), 4.7 (m, 1H), 7.1 (t, 1H), 7.15 (m, 3H),

7.3 (s, 1H), 7.5 (d, 1H), 7.7 (d, 1H), 8.35 (d, 1H), 8.5 (d, 2H),

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-Cyclop en tyla m id e (6f). Compound 6f was

prepared by subjecting compound 5f to general procedure G.

Yield ) 22%. Purity: >95% (HPLC method E). ¹H NMR (300

MHz, DMSO): δ 0.75 (dd, 6H), 1.0 (m, 1H), 1.2-1.8 (m, 10H),

1.95 (dd, 1H), 2.05 (dd, 1H), 2.7 (m, 1H), 2.95 (dd, 1H), 3.05

(dd, 1H), 3.95 (m, 1H), 4.45 (m, 1H), 6.95 (t, 1H), 7.05 (t, 1H),

7.1 (s, 1H), 7.3 (d, 1H), 7.55 (d, 1H), 7.6 (d, 1H), 8.0 (d, 1H),

8.75 (bs, 1H), 10.4 (bs, 1H), 10.8 (s, 1H). Anal. (C₂₄H₃₄N₄O₄)

C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-[(S)-1-In d a n yl]a m id e (6g). Compound 6g

was prepared by subjecting compound 5g to general procedure

G. Yield ) 21%. Purity: >94% (HPLC method E). ¹H NMR

(300 MHz, DMSO): δ 0.75 (dd, 6H), 1.0 (m, 1H), 1.35 (m, 2H),

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 217

8.65 (t, 1H), 8.9 (s, 1H), 10.55 (s, 1H), 11.0 (s, 1H). Anal.

(C₂₅H₃₁N₅O₄‚C₃H₈O) C, H, N.

1H), 8.9 (s, 1H), 10.5 (s, 1H), 10.8 (s, 1H), 12.1 (s, 1H). Anal.

(C₂₇H₃₂N₆O₄‚H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-[3-(1-Im id a zolylp r op yl)]a m id e (6v). Com-

pound 6v was prepared by subjecting compound 5v to general

procedure G. Yield ) 19%. Purity: >95% (HPLC method E).

¹H NMR (300 MHz, DMSO): δ 0.7 (dd, 6H), 1.0 (m, 1H), 1.4

(m, 2H), 1.7 (m, 2H), 1.95 (dd, 1H), 2.15 (dd, 1H), 2.7 (m, 1H),

3.0 (m, 3H), 3.15 (dd, 1H), 3.8 (m, 2H), 4.45 (m, 1H), 6.9 (s,

1H), 7.0 (t, 1H), 7.05 (t, 1H), 7.1 (s, 1H), 7.15 (s, 1H), 7.3 (d,

1H), 7.6 (m, 2H), 7.95 (m, 1H), 8.1 (d, 1H), 8.8 (s, 1H), 10.4 (s,

1H), 10.8 (s, 1H). Anal. (C₂₅H₃₄N₆O₄) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

t r yp t op h a n N-[3-(4-Mor p h olin ylp r op yl)]a m id e (6w ).⁵⁵

Compound 6w was prepared by subjecting compound 5w to

general procedure G. Yield ) 38%. Purity: >99% (HPLC

method A). ¹H NMR (300 MHz, DMSO): δ 0.9 (dd, 6H), 1.15

(m, 1H), 1.4-1.6 (m, 4H), 2.05 (dd, 1H), 2.15 (dd, 1H), 2.25 (t,

2H), 2.3-2.4 (m, 4H), 2.8 (m, 1H), 3.0-3.25 (m, 4H), 3.65 (m,

4H), 4.55 (m, 1H), 7.05 (t, 1H), 7.15 (t, 1H), 7.25 (s, 1H), 7.45

(d, 1H), 7.7 (d, 1H), 7.9 (t, 1H), 8.15 (d, 1H), 8.95 (bs, 1H),

10.5 (s, 1H), 10.9 (s, 1H). Anal. (C₂₆H₃₉N₅O₅‚0.5H₂O) C, H,

N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-(3-P yr id ylm eth yl)a m id e (6o). Compound

6o was prepared by subjecting compound 5o to general

procedure G. Yield ) 44%. TLC: R_f) 0.65 (CHCl₃/MeOH/

H₂O, 100/45/5). Purity: >92% (HPLC method A). ¹H NMR

(300 MHz, DMSO): δ 0.85 (dd, 6H), 1.15 (m, 1H), 1.45 (m,

2H), 2.05 (dd, 1H), 2.2 (dd, 1H), 2.85 (m, 1H), 3.15 (dd, 1H),

3.25 (dd, 1H), 4.3-4.5 (m, 2H), 4.65 (m, 1H), 7.05 (t, 1H), 7.15

(t, 1H), 7.25 (s, 1H), 7.4 (dd, 1H), 7.45 (d, 1H), 7.55 (d, 1H),

7.7 (d, 1H), 8.3 (d, 1H), 8.55 (s, 2H), 8.6 (t, 1H), 8.9 (s, 1H),

10.55 (s, 1H), 10.95 (s, 1H). Anal. (C₂₅H₃₁N₅O₄) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-(2-P yr id ylm eth yl)a m id e (6p ). Compound

6p was prepared by subjecting compound 5p to general

procedure G. Yield ) 15%. Purity: >98% (HPLC method D).

¹H NMR (300 MHz, DMSO): δ 0.8 (dd, 6H), 1.0 (m, 1H), 1.4

(m, 2H), 1.95 (dd, 1H), 2.05 (dd, 1H), 2.7 (m, 1H), 3.05 (dd,

1H), 3.2 (dd, 1H), 4.3 (d, 2H), 4.6 (m, 1H), 6.95-7.1 (m, 3H),

7.2 (s, 1H), 7.3 (m, 1H), 7.4 (d, 1H), 7.6 (m, 2H), 8.2 (d, 1H),

8.5 (m, 2H), 8.8 (s, 1H), 10.4 (s, 1H), 10.8 (s, 1H). Anal.

(C₂₅H₃₁N₅O₄‚0.25H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N,N-Dim eth yla m id e (6x). Compound 6x was

prepared by subjecting compound 5x to general procedure G.

Yield ) 28%. Purity: >96% (HPLC method E). ¹H NMR (300

MHz, DMSO): δ 0.8 (dd, 6H), 1.05 (m, 1H), 1.4 (m, 2H), 1.9-

2.1 (m, 2H), 2.75 (s, 3H), 2.77 (s, 3H), 2.78 (m, 1H), 2.9 (dd,

1H), 3.05 (dd, 1H), 4.9 (m, 1H), 7.0 (t, 1H), 7.05 (t, 1H), 7.1 (s,

1H), 7.35 (d, 1H), 7.55 (d, 1H), 8.2 (d, 1H), 8.7 (s, 1H), 10.35

(s, 1H), 10.8 (s, 1H). Anal. (C₂₁H₃₀N₄O₄) C, H, N: calcd, 13.92;

found, 13.15.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n P yr olid in yla m id e (6y). Compound 6y was

prepared by subjecting compound 5y to general procedure G.

Yield ) 18%. Purity: >90% (HPLC method E). ¹H NMR (300

MHz, DMSO): δ 0.8 (dd, 6H), 1.0 (m, 1H), 1.4 (m, 4H), 1.6 (m,

2H), 1.9-2.1 (m, 2H), 2.8 (m, 2H), 3.0 (dd, 1H), 3.05-3.2 (m,

4H), 4.7 (m, 1H), 7.0 (t, 1H), 7.05 (t, 1H), 7.15 (s, 1H), 7.25 (d,

1H), 7.5 (d, 1H), 8.2 (d, 1H), 8.7 (s, 1H), 10.4 (s, 1H), 10.8 (s,

1H). Anal. (C₂₃H₃₂N₄O₄) C, H, N: calcd, 13.07; found, 12.34.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n P ip er id in yla m id e (6z). Compound 6z was

prepared by subjecting compound 5z to general procedure G.

Yield ) 27%. Purity: >93% (HPLC method E). ¹H NMR (300

MHz, DMSO): δ 0.8 (dd, 6H), 1.0 (m, 1H), 1.2-1.6 (m, 8H),

1.9 (dd, 1H), 2.1 (dd, 1H), 2.8 (m, 1H), 2.9 (dd, 1H), 3.1 (dd,

1H), 3.2-3.4 (m, 4H), 5.0 (m, 1H), 6.95-7.1 (m, 3H), 7.3 (d,

1H), 7.6 (d, 1H), 8.3 (d, 1H), 8.7 (s, 1H), 10.5 (s, 1H), 10.8 (s,

1H). Anal. (C₂₄H₃₄N₄O₄‚1.5H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n Mor p h olin yla m id e (6a a ). Compound 6a a was

prepared by subjecting compound 5a a to general procedure

G. Yield ) 32%. TLC: R_f) 0.71 (CHCl₃/MeOH/H₂O, 100/45/

5). Purity: >99% (HPLC method A). ¹H NMR (300 MHz,

DMSO): δ 0.95 (dd, 6H), 1.15 (m, 1H), 1.55 (m, 2H), 2.05 (dd,

1H), 2.20 (dd, 1H), 2.9 (m, 2H), 3.05 (dd, 1H), 3.2-3.3 (m, 3H),

3.3-3.5 (m, 5H), 5.05 (m, 1H), 7.05 (t, 1H), 7.15 (t, 1H), 7.25

(s, 1H), 7.45 (d, 1H), 7.7 (d, 1H), 8.5 (d, 1H), 8.85 (s, 1H), 10.5

(s, 1H), 10.95 (s, 1H). Anal. (C₂₃H₃₂N₄O₅) C, H, N.

3-(N-Hyd r oxyca r b a m oyl)-2(R)-(isobu t ylp r op ion yl)-^D-

tr yp top h a n Meth yla m id e (6bb). Compound 6bb was pre-

pared by subjecting compound 5bb to general procedure G.

Yield ) 38%. Purity: >99% (HPLC method A). ¹H NMR (300

MHz, DMSO): δ 0.55 (d, 3H), 0.65 (d, 3H), 0.75-0.85 (m, 2H),

1.15 (m, 1H), 1.95 (dd, 1H), 2.15 (dd, 1H), 2.55-2.65 (m, 1H),

2.65 (d, 3H), 2.8 (dd, 1H), 3.3 (dd, 1H), 4.4 (m, 1H), 6.95 (t,

1H), 7.05 (t, 1H), 7.1 (s, 1H), 7.3 (d, 1H), 7.55 (d, 1H), 7.9 (m,

1H), 8.25 (d, 1H), 8.8 (s, 1H), 10.5 (s, 1H), 10.8 (s, 1H).

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

[3-(1-m eth ylin d olyl)]a la n in e N-Meth yla m id e (6cc). Com-

pound 6cc was prepared by subjecting compound 5cc to

general procedure G. Yield ) 42%. TLC: R_f) 0.48 (MeOH/

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-[2-(2-P yr id yl)eth yl]a m id e (6q). Compound

6q was prepared by subjecting compound 5q to general

procedure G. Yield ) 12%. Purity: >97% (HPLC method D).

¹H NMR (300 MHz, DMSO): δ 0.85 (dd, 6H), 1.1 (m, 1H), 1.5

(m, 2H), 2.05 (dd, 1H), 2.15 (dd, 1H), 2.8 (m, 1H), 2.9 (t, 2H),

3.05 (dd, 1H), 3.15 (dd, 1H), 3.5 (m, 2H), 4.55 (m, 1H), 7.05 (t,

1H), 7.15 (t, 1H), 7.2 (d, 1H), 7.3 (m, 2H), 7.4 (d, 1H), 7.65 (d,

1H), 7.8 (dt, 1H), 8.05 (t, 1H), 8.15 (d, 1H), 8.6 (d, 1H), 8.9 (s,

1H), 10.5 (s, 1H), 10.9 (s, 1H). Anal. (C₂₆H₃₃N₅O₄‚0.25H₂O)

C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yptoph an N-[2-(4-Hydr oxyph en yl)eth yl]am ide (6r ). Com-

pound 6r was prepared by subjecting compound 5r to general

procedure G. Yield ) 17%. TLC: R_f) 0.38 (15% MeOH/

CHCl₃). Purity: >99% (HPLC method A). ¹H NMR (300 MHz,

DMSO): δ 0.85 (dd, 6H), 1.15 (m, 1H), 1.5 (m, 2H), 2.05 (dd,

1H), 2.15 (dd, 1H), 2.6 (m, 2H), 2.8 (m, 1H), 3.05 (dd, 1H), 3.2

(dd, 1H), 3.2-3.35 (m, 2H), 4.55 (m, 1H), 6.75 (d, 2H), 7.05 (d,

2H), 7.05-7.2 (m, 2H), 7.25 (s, 1H), 7.45 (d, 1H), 7.7 (d, 1H),

8.0 (t, 1H), 8.15 (d, 1H), 8.9 (bs, 1H), 9.3 (bs, 1H), 10.5 (bs,

1H), 10.9 (bs, 1H). Anal. (C₂₇H₃₄N₄O₅‚0.5H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n F u r fu r yla m id e (6s). Compound 6s was pre-

pared by subjecting compound 5s to general procedure G.

Yield ) 18%. Purity: >96% (HPLC method E). ¹H NMR (300

MHz, DMSO): δ 0.75 (dd, 6H), 1.0 (m, 1H), 1.3 (m, 2H), 1.9

(dd, 1H), 2.05 (dd, 1H), 2.6 (m, 1H), 3.0 (dd, 1H), 3.15 (dd, 1H),

4.25 (m, 2H), 4.5 (m, 1H), 6.15 (s, 1H), 6.4 (s, 1H), 6.95 (t, 1H),

7.05 (t, 1H), 7.1 (s, 1H), 7.3 (d, 1H), 7.6 (m, 2H), 8.2 (d, 1H),

8.75 (bt, 1H), 8.8-10.4 (broad signals, 2H), 10.8 (bs, 1H). Anal.

(C₂₄H₃₀N₄O₅‚2.0H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-(2-Th ia zolylm eth yl)a m id e (6t). Compound

6t was prepared by subjecting compound 5t to general

procedure G. Yield ) 43%. TLC: R_f) 0.49 (MeOH/CHCl₃,

1/6). Purity: >98% (HPLC method A). ¹H NMR (300 MHz,

DMSO): δ 0.85 (dd, 6H), 1.1 (m, 1H), 1.5 (m, 2H), 2.0-2.2 (m,

2H), 2.8 (m, 1H), 3.1 (dd, 1H), 3.25 (dd, 1H), 3.5 (m, 1H), 4.7

(m, 3H), 7.05-7.2 (m, 2H), 7.25 (s, 1H), 7.4 (d, 1H), 7.7 (m,

1H), 7.8 (s, 1H), 8.25 (d, 1H), 8.85 (s, 1H), 8.95 (t, 1H), 10.5 (s,

1H), 10.9 (s, 1H). Anal. (C₂₃H₂₉N₅O₄S) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yptoph an N-(2-Ben zim idazolylm eth yl)am ide (6u ). Com-

pound 6u was prepared by subjecting compound 5u to general

procedure G. Yield ) 22%. Purity: >99% (HPLC method E).

¹H NMR (300 MHz, DMSO): δ 0.7 (dd, 6H), 1.0 (m, 1H), 1.4

(m, 2H), 2.0 (dd, 1H), 2.1 (dd, 1H), 2.7 (m, 1H), 3.1 (dd, 1H),

3.25 (dd, 1H), 4.4-4.6 (m, 3H), 7.0 (t, 1H), 7.1 (t, 1H), 7.2 (m,

3H), 7.35 (d, 1H), 7.5 (m, 2H), 7.6 (d, 1H), 8.25 (d, 1H), 8.6 (t,

218 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Levy et al.

CHCl₃, 1/6). Purity: >99% (HPLC method A). ¹H NMR (300

MHz, DMSO): δ 0.85 (dd, 6H), 1.1 (m, 1H), 1.45 (m, 2H), 2.05

(dd, 1H), 2.2 (dd, 1H), 2.65 (d, 3H), 2.75 (m, 1H), 3.05 (dd, 1H),

3.2 (dd, 1H), 4.85 (s, 3H), 4.5 (m, 1H), 7.1 (t, 1H), 7.2 (m, 2H),

7.45 (d, 1H), 7.65 (d, 1H), 7.95 (m, 1H), 8.1 (d, 1H), 8.9 (s, 1H),

10.5 (s, 1H). Anal. (C₂₁H₃₀N₄O₄) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(3-b en zot h ien yl)a la n in e N-Met h yla m id e (6d d ). Com-

pound 6d d was prepared by subjecting compound 5d d to

general procedure G. Yield ) 10%. TLC: R_f) 0.55 (CHCl₃/

MeOH/H₂O, 150/45/5). Purity: >94% (HPLC method A). ¹H

NMR (300 MHz, DMSO): δ 0.85 (dd, 6H), 1.1 (m, 1H), 1.3-

1.5 (m, 2H), 2.05 (dd, 1H), 2.2 (dd, 1H), 2.7 (t, 3H), 2.75 (m,

1H), 3.25 (dd, 1H), 3.4 (dd, 1H), 4.65 (m, 1H), 7.45-7.55 (m,

3H), 8.0 (d, 1H), 8.05-8.15 (m, 2H), 8.3 (d, 1H), 8.9 (s, 1H),

10.55 (s, 1H). Anal. (C₂₀H₂₇N₃O₄S) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(1-n a p h th yl)a la n in e N-Meth yla m id e (6ee). Compound

6ee was prepared by subjecting compound 5ee to general

procedure G. Yield ) 25%. TLC: R_f) 0.79 (CHCl₃/MeOH/

H₂O, 200/45/5). Purity: >93% (HPLC method L). ¹H NMR

(300 MHz, DMSO): δ 0.85 (dd, 6H), 1.15 (m, 1H), 1.3-1.5 (m,

2H), 2.05 (dd, 1H), 2.2 (dd, 1H), 2.7 (m, 4H), 3.4 (dd, 1H), 3.7

(dd, 1H), 4.65 (m, 1H), 7.45-7.55 (m, 2H), 7.65-7.75 (m, 2H),

7.9 (d, 1H), 8.05 (d, 1H), 8.1 (m, 1H), 8.3-8.4 (m, 2H), 8.95 (s,

1H), 10.6 (bs, 1H). Anal. (C₂₂H₂₉N₃O₄‚1.67H₂O) C, N, H; calcd,

7.59; found, 6.93.

H₂O, 200/45/5). Purity: >88% (HPLC method E). ¹H NMR

(300 MHz, DMSO): δ 0.65 (dd, 6H), 0.95 (m, 1H), 1.2-1.35

(m, 2H), 1.4 (d, 3H), 1.9 (dd, 1H), 2.0 (dd, 1H), 2.6 (m, 1H), 3.0

(dd, 1H), 3.2 (dd, 1H), 4.6 (m, 1H), 4.9 (m, 1H), 7.15 (s, 5H),

7.35-7.5 (m, 3H), 7.7 (s, 1H), 7.75-7.85 (m, 3H), 8.2 (d, 1H),

8.45 (d, 1H), 8.8-10.5 (broad signals, 2H). Anal.

(C₂₉H₃₅N₃O₄‚H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(2-n a p h th yl)a la n in e N-Ben zyla m id e (6k k ). Compound

6k k was prepared by subjecting compound 5k k to general

procedure G. Yield ) 11%. TLC: R_f) 0.67 (CHCl₃/MeOH/

H₂O, 150/45/5). Purity: >98% (HPLC method E). ¹H NMR

(300 MHz, DMSO): δ 0.8 (dd, 6H), 1.1 (m, 1H), 1.3-1.5 (m,

2H), 2.0 (dd, 1H), 2.15 (dd, 1H), 2.8 (m, 1H), 3.2 (dd, 1H), 3.35

(dd, 1H), 4.4 (d, 2H), 4.75 (m, 1H), 7.25 (m, 2H), 7.3 (m, 3H),

7.5-7.65 (m, 3H), 7.85 (s, 1H), 7.9-8.05 (m, 3H), 8.85 (d, 1H),

8.6 (t, 1H), 8.9 (s, 1H), 10.5 (s, 1H). Anal. (C₂₈H₃₃N₃O₄‚0.33H₂O)

C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(3-qu in olyl)a la n in e N-Meth yla m id e (6ll). Compound 6ll

was prepared by subjecting compound 5ll to general procedure

G. Yield ) 29%. TLC: R_f) 0.50 (MeOH/CHCl₃, 1/6).

Purity: >95% (HPLC method F). ¹H NMR (300 MHz,

DMSO): δ 0.65 (dd, 6H), 0.85-1.3 (m, 3H), 1.9 (dd, 1H), 2.05

(dd, 1H), 2.6 (m, 4H), 3.05 (dd, 1H), 3.25 (dd, 1H), 4.5 (m, 1H),

7.55 (t, 1H), 7.7 (m, 1H), 7.85-8.0 (m, 3H), 8.15 (s, 1H), 8.2

(m, 1H), 8.75 (s, 1H), 8.9 (s, 1H), 10.4 (s, 1H). Anal.

(C₂₁H₂₈N₄O₄‚0.67H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(1-n a p h th yl)a la n in e N-[3-(4-Mor p h olin ylp r op yl)]a m id e

(6ff). Compound 6ff was prepared by subjecting compound

5ff to general procedure G. Yield ) 41%. TLC: R_f) 0.55

(CHCl₃/MeOH/H₂O, 150/45/5). Purity: >93% (HPLC method

A). ¹H NMR (300 MHz, DMSO): δ 0.9 (dd, 6H), 1.15 (m, 1H),

1.4-1.5 (m, 2H), 1.5-1.65 (m, 2H), 2.05 (dd, 1H), 2.2 (dd, 1H),

2.25 (m, 2H), 2.4 (m, 4H), 2.75 (m, 1H), 3.15 (m, 2H), 3.4 (m,

2H), 3.65 (m, 4H), 4.65 (m, 1H), 7.45-7.55 (m, 2H), 7.6-7.75

(m, 2H), 7.9 (m, 2H), 8.05 (d, 1H), 8.25 (d, 1H), 8.35 (d, 1H),

8.85 (bs, 1H), 10.5 (bs, 1H). Anal. (C₂₈H₄₀N₄O₅) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(2-n a p h th yl)a la n in e N-Meth yla m id e (6gg). Compound

6gg was prepared by subjecting compound 5gg to general

procedure G. Yield ) 54%. TLC: R_f) 0.60 (CHCl₃/MeOH/

H₂O, 150/45/5). Purity: >99% (HPLC method A). ¹H NMR

(300 MHz, DMSO): δ 0.75 (dd, 6H), 1.0 (m, 1H), 1.2-1.4 (m,

2H), 2.0 (dd, 1H), 2.15 (dd, 1H), 2.7 (m, 4H), 3.1 (dd, 1H), 3.35

(dd, 1H), 4.6 (m, 1H), 7.45-7.6 (m, 3H), 7.8 (s, 1H), 7.9-8.0

(m, 3H), 8.1 (m, 1H), 8.25 (d, 1H), 8.9 (s, 1H), 10.55 (s, 1H).

Anal. (C₂₂H₂₉N₃O₄) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(8-qu in olyl)alan in e Meth ylam ide (6m m ). Compound 6m m

was prepared by subjecting compound 5m m to general pro-

cedure G. Yield ) 37%. TLC: R_f) 0.48 (MeOH/CHCl₃, 1/9).

Purity: >88% (HPLC method A). ¹H NMR (300 MHz,

DMSO): δ 0.65 (dd, 6H), 0.9 (m, 1H), 1.15 (m, 2H), 1.9 (dd,

1H), 2.0 (dd, 1H), 2.6 (d, 3H), 3.4 (m, 1H), 3.75 (dd, 1H), 4.65

(m, 1H), 7.45-7.6 (m, 4H), 7.8 (m, 2H), 8.1 (d, 1H), 8.35 (d,

1H), 8.8 (s, 1H), 8.95 (s, 1H), 10.45 (s, 1H). Anal.

(C₂₁H₂₈N₄O₄‚0.75H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(4,4′-bip h en yl)a la n in e N-Meth yla m id e (6oo). Compound

6oo was prepared by subjecting compound 5oo to general

procedure G. Yield ) 10%. TLC: R_f) 0.66 (CHCl₃/MeOH/

H₂O, 150/45/5). Purity: >97% (HPLC method I). ¹H NMR

(300 MHz, DMSO): δ 0.85 (dd, 6H), 1.1 (m, 1H), 1.3-1.5 (m,

2H), 2.05 (dd, 1H), 2.2 (dd, 1H), 2.7 (m, 4H), 3.0 (dd, 1H), 3.2

(dd, 1H), 4.55 (m, 1H), 7.4-7.5 (m, 3H), 7.55 (t, 2H), 7.65 (d,

2H), 7.75 (d, 2H), 8.05 (m, 1H), 8.2 (d, 1H), 8.9 (s, 1H), 10.55

(s, 1H). Anal. (C₂₄H₃₁N₃O₄‚0.33H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(2-n a p h th yl)a la n in e N-[3-(4-Mor p h olin ylp r op yl)]a m id e

(6h h ). Compound 6h h was prepared by subjecting compound

5h h to general procedure G. Yield ) 33%. TLC: R_f) 0.58

(CHCl₃/MeOH/H₂O, 150/45/5). Purity: >89% (HPLC method

E). ¹H NMR (300 MHz, DMSO): δ 0.8 (dd, 6H), 1.05 (m, 1H),

1.45 (m, 2H). 1.55 (m, 2H), 2.0 (dd, 1H), 2.15 (dd, 1H), 2.25

(t, 2H), 2.35 (m, 4H), 2.75 (m, 1H), 3.05-3.2 (m, 3H), 3.3 (dd,

1H), 3.65 (m, 4H), 4.65 (m, 1H), 7.5-7.65 (m, 3H), 7.8 (s, 1H),

7.9-8.05 (m, 4H), 8.25 (d, 1H), 8.95 (bs, 1H), 10.5 (s, 1H). Anal.

(C₂₈H₄₀N₄O₅‚0.5H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(2-n a p h th yl)a la n in e N-[2-(4-Hyd r oxyp h en yl)eth yl]a m id e

(6ii). Compound 6ii was prepared by subjecting compound

5ii to general procedure G. Yield ) 10%. TLC: R_f) 0.59

(CHCl₃/MeOH/H₂O, 150/45/5). Purity: >93% (HPLC method

I). ¹H NMR (300 MHz, DMSO): δ 0.6 (d, 3H), 0.8 (d, 3H), 1.0

(m, 1H), 1.2 (m, 1H), 1.3 (m, 1H), 2.0 (dd, 1H), 2.2 (dd, 1H),

2.5-2.7 (m, 3H), 3.1 (dd, 1H), 3.2-3.5 (m, 3H), 4.6 (m, 1H),

6.8 (d, 2H), 7.1 (d, 2H), 7.5-7.65 (m, 3H), 7.8 (s, 1H), 7.9-8.0

(m, 3H), 8.4 (d, 1H), 8.7 (bs, 1H), 8.8-11 (broad signals, 3H).

Anal. (C₂₉H₃₅N₃O₅‚1.33H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(4,4′-bip h en yl)a la n in e N-[3-(4-Mor p h olin ylp r op yl)]a m id e

(6p p ). Compound 6p p was prepared by subjecting compound

5p p to general procedure G. Yield ) 13%. TLC: R_f) 0.62

(CHCl₃/MeOH/H₂O, 150/45/5). Purity: >96% (HPLC method

I). ¹H NMR (300 MHz, DMSO): δ 0.85 (dd, 6H), 1.1 (m, 1H),

1.3-1.5 (m, 2H), 1.55-1.65 (m, 2H), 2.05 (dd, 1H), 2.15 (dd,

1H), 2.25-2.35 (t, 2H), 2.35-2.45 (m, 4H), 2.75 (m, 1H), 3.0

(dd, 1H), 3.1-3.25 (m, 3H), 3.6-3.7 (m, 4H), 4.55 (m, 1H), 7.4

(d, 2H), 7.45 (d, 1H), 7.55 (t, 2H), 7.7 (d, 2H), 7.75 (d, 2H), 8.0

(t, 1H), 8.25 (d, 1H), 8.95 (bs, 1H), 10.5 (s, 1H). Anal.

(C₃₀H₄₂N₄O₅‚0.5H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(4,4′-b ip h en yl)a la n in e N-[2-(4-H yd r oxyp h en yl)et h yl]-

a m id e (6qq). Compound 6qq w a s prepared by subjecting

compound 5qq to general procedure G. Yield ) 18%. TLC:

R_f) 0.30 (MeOH/CHCl₃, 1/20). Purity: >97% (HPLC method

E). ¹H NMR (300 MHz, DMSO): δ 0.65 (dd, 6H), 0.95 (m, 1H),

1.2 (m, 1H), 1.35 (m, 1H), 1.9 (dd, 1H), 2.15 (dd, 1H), 2.6 (m,

3H), 2.85 (m, 2H), 3.1-3.3 (m, 2H), 4.45 (m, 1H), 6.7 (d, 2H),

7.0 (d, 2H), 7.35 (m, 3H), 7.45 (m, 2H), 7.55 (d, 2H), 7.65 (d,

2H), 8.2 (m, 1H), 8.5 (bs, 1H), 8.8-9.8 (broad signals, 2H), 10.4

(broad signal, 1H). Anal. (C₃₁H₃₇N₃O₅‚H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(4,4′-bip h en yl)a la n in e N-[(S)-Meth ylben zyl]a m id e (6r r ).

Compound 6r r was prepared by subjecting compound 5r r to

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(2-n aph th yl)alan in e N-[(S)-Meth ylben zyl]am ide (6jj). Com-

pound 6jj was prepared by subjecting compound 5jj to general

procedure G. Yield ) 10%. TLC: R_f) 0.55 (CHCl₃/MeOH/

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 219

general procedure G. Yield ) 18%. TLC: R_f) 0.50 (MeOH/

CHCl₃, 1/9). Purity: >92% (HPLC method F). ¹H NMR (300

MHz, DMSO): δ 0.75 (dd, 6H), 0.95 (m, 1H), 1.2-1.45 (m, 5H),

1.9 (dd, 1H), 2.05 (dd, 1H), 2.6 (m, 1H), 2.85 (dd, 1H), 3.05

(dd, 1H), 4.55 (m, 1H), 4.9 (m, 1H), 7.1-7.4 (m, 8H), 7.45 (t,

2H), 7.55 (d, 2H), 7.65 (m, 2H), 8.2 (d, 1H), 8.5-8.6 (m, 1H),

8.8-10.5 (broad signals, 2H). Anal. (C₃₁H₃₇N₃O₄‚0.5H₂O) C,

H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(4,4′-bip h en yl)a la n in e N-Ben zyla m id e (6ss). Compound

6ss was prepared by subjecting compound 5ss to general

procedure G. Yield ) 10%. TLC: R_f) 0.35 (10% MeOH/

CHCl₃). Purity: >99% (HPLC method A). ¹H NMR (300 MHz,

DMSO): δ 0.85 (dd, 6H), 1.1 (m, 1H), 1.3-1.5 (m, 2H), 2.05

(dd, 1H), 2.15 (dd, 1H), 2.8 (m, 1H), 3.0 (dd, 1H), 3.2 (dd, 1H),

4.4 (m, 2H), 4.7 (m, 1H), 7.25-7.5 (m, 8H), 7.55 (t, 2H), 7.7 (d,

2H), 7.75 (d, 2H), 8.35 (d, 1H), 8.6 (t, 1H), 8.9 (s, 1H), 10.5 (bs,

1H). Anal. (C₃₀H₃₅N₃O₄‚1.33H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

p h en yla la n in e N-Meth yla m id e (6tt). Compound 6tt was

prepared by subjecting compound 5tt to general procedure G.

Yield ) 20%. TLC: R_f) 0.39 (MeOH/CHCl₃, 2/9). Purity:

>85% (HPLC method E). ¹H NMR (300 MHz, DMSO): δ 0.8

(dd, 6H), 1.05 (m, 1H), 1.2 (m, 1H), 1.35 (m, 1H), 2.0 (dd, 1H),

2.25 (dd, 1H), 2.55 (m, 1H), 2.7 (d, 3H), 2.95 (dd, 1H), 3.25

(dd, 1H), 4.45 (m, 1H), 7.2-7.4 (m, 6H), 8.25 (d, 1H), 8.8 (bs,

1H), 10.4 (bs, 1H). Anal. (C₁₈H₂₇N₃O₄) C, H; N: calcd, 12.03;

found, 11.54.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(3-p yr id yl)a la n in e N-Ben zyla m id e (6u u ). Compound 6u u

was prepared by subjecting compound 5u u to general proce-

dure G. Yield ) 15%. TLC: R_f) 0.45 (MeOH/CHCl₃, 1/6).

Purity: >85% (HPLC method F). ¹H NMR (300 MHz,

DMSO): δ 0.75 (dd, 6H), 0.95 (m, 1H), 1.2-1.45 (m, 2H), 1.8-

2.0 (m, 2H), 2.15 (m, 1H), 2.85 (dd, 1H), 3.05 (dd, 1H), 4.25

(m, 2H), 4.5 (m, 1H), 7.1-7.3 (m, 5H), 7.65 (d, 1H), 8.25 (d,

1H), 8.35-8.55 (m, 4H), 8.85 (s, 1H), 10.35 (s, 1H). Anal.

(C₂₃H₃₀N₄O₄‚H₂O) C, H, N.

DMSO): δ 0.75 (dd, 6H), 0.9 (m, 1H), 1.1-1.4 (m, 2H), 1.8-

2.0 (m, 2H), 2.6 (m, 1H), 2.85 (dd, 1H), 3.05 (dd, 1H), 4.25 (m,

2H), 4.55 (m, 1H), 7.1-7.4 (m, 7H), 8.2 (d, 1H), 8.4-8.6 (m,

3H), 8.75 (s, 1H), 10.35 (s, 1H). Anal. (C₂₃H₃₀N₄O₄‚0.25H₂O)

C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

ter t-leu cin e N-Meth yla m id e (6a a a ). Compound 6a a a was

prepared by subjecting compound 5a a a to general procedure

G. Yield ) 23%. TLC: R_f) 0.54 (CHCl₃/MeOH/H₂O, 150/45/

5). Purity: >96% (HPLC method G). ¹H NMR (300 MHz,

DMSO): δ 0.9 (dd, 6H), 1.0 (s, 9H), 1.2 (m, 1H), 1.75 (m, 2H),

2.1 (dd, 1H), 2.25 (dd, 1H), 2.65 (d, 3H), 2.95 (m, 1H), 4.25 (d,

1H), 7.8 (d, 1H), 8.0 (m, 1H), 8.8 (bs, 1H), 10.45 (s, 1H). Anal.

(C₁₅H₂₉N₃O₄) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

a br in e N-Meth yla m id e (6bbb). Compound 6bbb was pre-

pared by subjecting compound 5bbb to general procedure G.

Yield ) 23%. Purity: >85% (HPLC method M). ¹H NMR (300

MHz, DMSO): δ 0.0 (m, 0.5H), 0.3 (dd, 3H), 0.8 (m, 0.5H), 0.9

(d, 3H), 1.1-1.2 (m, 1H), 1.45-1.6 (m, 1H), 1.95-2.3 (m, 2H),

2.65 (d, 1.5H), 2.8 (d, 1.5H), 2.9 (s, 1.5H), 3.0-3.2 (m, 2.5H),

3.35-3.6 (m, 2H), 4.8-5.3 (m + m, 1H), 7.05-7.2 (m, 3H), 7.45

(m, 1H), 7.6-7.75 (m, 1H), 7.8-8.35 (m, 1H), 8.85-9.0 (s + s,

1H), 10.55-10.65 (s + s, 1H), 10.85-11.0 (s + s, 1H). Anal.

(C₂₁H₃₀N₄O₄) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

a br in e N-[3-(4-Mor p h olin ylp r op yl)]a m id e (6cc). Com-

pound 6ccc was prepared by subjecting compound 5ccc to

general procedure G. Yield ) 10%. TLC: R_f) 0.58 (CHCl₃/

MeOH/H₂O, 150/45/5). Purity: >95% (HPLC method J ). ¹H

NMR (300 MHz, DMSO): δ 0.0 (m, 0.5H), 0.35 (dd, 3H), 0.8

(m, 0.5H), 0.9 (d, 3H), 1.1-1.25 (m, 1H), 1.5-1.65 (m, 2H),

1.7-1.8 (m, 1H), 1.95-2.5 (m, 9H), 2.9 (s, 1.5H), 3.0-3.1 (m,

1H), 3.1 (s, 1.5H), 3.15-3.25 (m, 2H), 3.3-3.45 (m, 1H), 3.6-

3.7 (m, 4H), 4.75-5.25 (m + m, 1H), 7.05-7.2 (m, 3H), 7.45

(m, 1H), 7.7 (m, 1H), 7.85-8.35 (t + t, 1H), 8.9-9.15 (s + s,

1H), 10.55-10.65 (s + s, 1H), 10.9-11.05 (s + s, 1H). Anal.

(C₂₇H₄₁N₅O₅‚2H₂O) C, N; H: calcd, 8.22; found, 7.67.

3-(N-H yd r oxyca r b a m oyl)-2(S)-(isob u t ylp r op ion yl)-^L-

t r yp t op h a n Met h yla m id e (6d d d ). Compound 6d d d was

prepared by subjecting compound 5d d d to general procedure

G. Yield ) 35%. Purity: >99% (HPLC method A). ¹H NMR

(300 MHz, DMSO): δ 0.55 (d, 3H), 0.65 (d, 3H), 0.75-0.85 (m,

2H), 1.15 (m, 1H), 1.95 (dd, 1H), 2.15 (dd, 1H), 2.55-2.65 (m,

1H), 2.65 (d, 3H), 2.85 (dd, 1H), 3.3 (dd, 1H), 4.4 (m, 1H), 7.45

(t, 1H), 7.55 (t, 1H), 7.6 (s, 1H), 7.3 (d, 1H), 7.55 (d, 1H), 7.9

(m, 1H), 8.2 (d, 1H), 8.75 (s, 1H), 10.5 (s, 1H), 10.8 (s, 1H).

Anal. (C₂₀H₂₈N₄O₄‚0.25H₂O) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(4-p yr id yl)a la n in e N-Meth yla m id e (6vv). Compound 6vv

was prepared by subjecting compound 5vv to general proce-

dure G. Yield ) 28%. TLC: R_f) 0.40 (CHCl₃/MeOH/H₂O,

200/45/5). Purity: >99% (HPLC method A). ¹H NMR (300

MHz, DMSO): δ 0.85 (dd, 6H), 1.05 (m, 1H), 1.3 (m, 1H), 1.4

(m, 1H), 2.05 (dd, 1H), 2.15 (dd, 1H), 2.7 (m, 4H), 2.95 (dd,

1H), 3.2 (dd, 1H), 4.55 (m, 1H), 7.35 (d, 2H), 8.1 (m, 1H), 8.25

(d, 1H), 8.55 (d, 2H), 8.9 (s, 1H), 10.55 (s, 1H). Anal.

(C₁₇H₂₆N₄O₄) C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(4-p yr id yl)a la n in e N-[2-(4-Hyd r oxyp h en yl)eth yl]a m id e

(6xx). Compound 6xx was prepared by subjecting compound

5xx to general procedure G. Yield ) 31%. TLC: R_f) 0.54

(CHCl₃/MeOH/H₂O, 150/45/5). Purity: >88% (HPLC method

F). ¹H NMR (300 MHz, DMSO): δ 0.85 (dd, 6H), 1.05 (m, 1H),

1.3-1.5 (m, 2H), 1.95-2.15 (m, 2H), 2.6-2.8 (m, 3H), 2.95 (dd,

1H), 3.1 (dd, 1H), 3.25-3.4 (m, 2H), 4.6 (m, 1H), 6.8 (d, 2H),

7.1 (d, 2H), 7.35 (d, 2H), 8.15 (t, 1H), 8.25 (d, 1H), 8.55 (d,

2H), 8.9 (s, 1H), 9.3 (s, 1H), 10.5 (s, 1H). Anal. (C₂₄H₃₂N₄O₅)

C, H, N.

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(4-pyr idyl)alan in e N-[(S)-Meth ylben zyl]am ide (6yy). Com-

pound 6yy was prepared by subjecting compound 5yy to

general procedure G. Yield ) 25%. TLC: R_f) 0.52 (CHCl₃/

MeOH/H₂O, 150/45/5). Purity: >94% (HPLC method E). ¹H

NMR (300 MHz, DMSO): δ 0.85 (dd, 6H), 1.1 (m, 1H), 1.3-

1.5 (m, 5H), 2.0-2.1 (m, 2H), 2.75 (m, 1H), 2.95 (dd, 1H), 3.15

(dd, 1H), 4.7 (m, 1H), 5.0 (m, 1H), 7.3-7.45 (m, 7H), 8.3 (d,

1H), 8.45 (d, 1H), 8.5 (d, 2H), 8.85 (s, 1H), 10.5 (s, 1H). Anal.

(C₂₄H₃₂N₄O₄) C, H, N.

3-(N-Hyd r oxyca r ba m oyl)-2(R)-Bu tylp r op ion yl-^L-tr yp -

top h a n Meth yla m id e (6eee). Compound 6eee was prepared

by subjecting compound 5ggg to general procedure G. Yield

) 36%. TLC: R_f) 0.46 (CHCl₃/MeOH/H₂O, 150/45/5). Pu-

rity: >99% (HPLC method A). ¹H NMR (300 MHz, DMSO):

δ 0.95 (t, 3H), 1.1-1.5 (m, 6H), 2.05 (dd, 1H), 2.2 (dd, 1H),

2.65 (m, 4H), 3.05 (dd, 1H), 3.2 (dd, 1H), 4.55 (m, 1H), 7.05 (t,

1H), 7.15 (t, 1H), 7.25 (s, 1H), 7.4 (d, 1H), 7.65 (d, 1H), 7.95

(m, 1H), 8.05 (d, 1H), 8.85 (bs, 1H), 10.5 (bs, 1H), 10.9 (s, 1H).

Anal. (C₂₀H₂₈N₄O₄) C, H, N.

3-(N-Hyd r oxyca r ba m oyl)-2(R)-h exylp r op ion yl-^L-tr yp -

top h a n Meth yla m id e (6fff). Compound 6fff was prepared

by subjecting compound 5iii to general procedure G. Yield )

57%. TLC: R_f) 0.52 (CHCl₃/MeOH/H₂O, 150/45/5). Purity:

>91% (HPLC method A). ¹H NMR (300 MHz, DMSO): δ 0.95

(t, 3H), 1.1-1.5 (m, 10H), 2.05 (dd, 1H), 2.2 (dd, 1H), 2.65 (m,

4H), 3.05 (dd, 1H), 3.2 (dd, 1H), 4.55 (m, 1H), 7.05 (t, 1H), 7.15

(t, 1H), 7.25 (s, 1H), 7.4 (d, 1H), 7.65 (d, 1H), 7.95 (m, 1H),

8.05 (d, 1H), 8.85 (bs, 1H), 10.5 (bs, 1H), 10.9 (s, 1H). Anal.

(C₂₂H₃₂N₄O₄‚0.33H₂O) C, H, N.

3-(N-Hyd r oxyca r ba m oyl)-2(R)-octylp r op ion yl-^L-tr yp -

top h a n Meth yla m id e (6ggg). Compound 6ggg was pre-

pared by subjecting compound 5k k k to general procedure G.

Yield ) 56%. TLC: R_f) 0.60 (CHCl₃/MeOH/H₂O, 150/45/5).

Purity: >92% (HPLC method A). ¹H NMR (300 MHz,

DMSO): δ 0.95 (t, 3H), 1.1-1.5 (m, 14H), 2.05 (dd, 1H), 2.2

3-(N-H yd r oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

(4-p yr id yl)a la n in e N-Ben zyla m id e (6zz). Compound 6zz

was prepared by subjecting compound 5zz to general procedure

G. Yield ) 10%. TLC: R_f) 0.55 (MeOH/CHCl₃, 1/3).

Purity: >86% (HPLC method B). ¹H NMR (300 MHz,

220 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Levy et al.

(dd, 1H), 2.65 (m, 4H), 3.05 (dd, 1H), 3.2 (dd, 1H), 4.55 (m,

1H), 7.05 (t, 1H), 7.15 (t, 1H), 7.25 (s, 1H), 7.4 (d, 1H), 7.65 (d,

1H), 7.95 (m, 1H), 8.05 (d, 1H), 8.85 (bs, 1H), 10.5 (bs, 1H),

10.9 (s, 1H). Anal. (C₂₄H₃₆N₄O₄‚0.25H₂O) C, H, N.

room temperature for 4.5 h, after which it was concentrated

to 50% its original volume. The resulting solution was

lyophilized giving compound 7f (3.69 g, 100%).

3-(N-Met h oxyca r b a m oyl)-2(R)-(isob u t ylp r op ion yl)-^L-

tr yp top h a n N-Meth yla m id e (8a ). Compound 8a was pre-

pared by reacting compound 6a with methyl iodide according

to general procedure H. Yield ) 20%. Purity: >92% (HPLC

method A). ¹H NMR (300 MHz, DMSO): δ 0.9 (dd, 6H), 1.15

(m, 1H), 1.5 (m, 2H), 2.05 (dd, 1H), 2.15 (dd, 1H), 2.65 (d, 3H),

2.8 (m, 1H), 3.1 (dd, 1H), 3.2 (dd, 1H), 3.65 (s, 3H), 4.55 (m,

1H), 7.05 (t, 1H), 7.15 (t, 1H), 7.2 (s, 1H), 7.4 (d, 1H), 7.65 (d,

1H), 7.9 (m, 1H), 8.1 (d, 1H), 10.9 (s, 1H), 11.1 (s, 1H). Anal.

(C₂₁H₃₀N₄O₄) C, H, N.

3-(N-Ben zyloxyca r ba m oyl)-2(R)-(isobu tylp r op ion yl)-^L-

tr yp top h a n N-Meth yla m id e (8b). Compound 8b was pre-

pared by reacting compound 6a with benzyl bromide according

to general procedure H. Yield ) 32%. Purity: >90% (HPLC

method A). ¹H NMR (300 MHz, DMSO): δ 0.75 (dd, 6H), 1.0

(m, 1H), 1.3-1.45 (m, 2H), 1.45 (dd, 1H), 2.1 (dd, 1H), 2.55 (d,

3H), 2.7 (m, 1H), 3.0 (dd, 1H), 3.15 (dd, 1H), 4.45 (m, 1H), 4.75

(m, 2H), 6.95 (t, 1H), 7.05 (t, 1H), 7.1 (s, 1H), 7.25-7.4 (m,

6H), 7.55 (d, 1H), 7.8 (m, 1H), 8.0 (d, 1H), 10.8 (s, 1H), 11.0 (s,

1H). Anal. (C₂₇H₃₄N₄O₄‚0.25H₂O) C, H, N.

3-(N-Hyd r oxyca r ba m oyl)-2(R)-[(isop r op yloxy)p r op io-

n yl]-^L-tr yp top h a n Meth yla m id e (6h h h ). Compound 6h h h

was prepared by subjecting compound 5lll to general procedure

G. Yield ) 39%. TLC: R_f) 0.46 (CHCl₃/MeOH/H₂O, 150/45/

5). Purity: >98% (HPLC method H). ¹H NMR (300 MHz,

DMSO): δ 1.0 (dd, 6H), 2.4 (m, 2H), 2.7 (d, 3H), 3.3 (d, 2H),

3.54 (m, 1H), 4.1 (m, 1H), 4.55 (m, 1H), 7.1 (t, 1H), 7.15 (t,

1H), 7.2 (d, 1H), 7.45 (t, 2H), 7.65 (d, 1H), 8.25 (m, 1H), 8.9 (s,

1H), 10.6 (s, 1H), 11.0 (s, 1H). Anal. (C₁₉H₂₆N₄O₅) C, H, N.

3-(N-Hyd r oxyca r ba m oyl)-2(R)-[(p en tyloxy)p r op ion yl]-

L-tr yp top h a n Meth yla m id e (6iii). Compound 6iii was

prepared by subjecting compound 5m m m to general procedure

G. Yield ) 22%. TLC: R_f) 0.51 (CHCl₃/MeOH/H₂O, 150/45/

5). Purity: >99% (HPLC method E). ¹H NMR (300 MHz,

DMSO): δ 0.95 (t, 3H), 1.15-1.35 (m, 4H), 1.35-1.5 (m, 2H),

2.4 (m, 2H), 2.7 (d, 3H), 3.2-3.35 (m, 4H), 4.0 (m, 1H), 4.6 (m,

1H), 7.05 (t, 1H), 7.15 (t, 1H), 7.2 (d, 1H), 7.45 (d, 1H), 7.6 (d,

1H), 7.65 (d, 1H), 8.25 (m, 1H), 8.95 (s, 1H), 10.6 (s, 1H), 11.0

(s, 1H). Anal. (C₂₁H₃₀N₄O₅) C, H, N.

3-(N-Hyd r oxyca r ba m oyl)-3(S)-h yd r oxy-2(R)-(isobu tyl-

p r op ion yl)-^L-t r yp t op h a n N-Met h yla m id e (6jjj). Com-

pound 6jjj was prepared by subjecting compound 5n n n to

general procedure G. Yield ) 46%. TLC: R_f) 0.32 (CHCl₃/

MeOH/H₂O, 150/45/5). Purity: >94% (HPLC method A). ¹H

NMR (300 MHz, DMSO): δ 0.85 (dd, 6H), 1.1 (m, 1H), 1.35-

1.6 (m, 2H), 2.65 (d, 3H), 2.7 (m, 1H), 3.1-3.3 (m, 2H), 3.95

(m, 1H), 4.55 (m, 1H), 5.65 (d, 1H), 7.05 (t, 1H), 7.15 (t, 1H),

7.25 (s, 1H), 7.45 (d, 1H), 7.65 (d, 1H), 7.85-7.95 (m, 2H), 8.95

(s, 1H), 10.7 (s, 1H), 10.85 (s, 1H). Anal. (C₂₀H₂₈N₄O₅‚0.25H₂O)

C, H, N.

3-(N-Hyd r oxyca r ba m oyl)-3(S)-h yd r oxy-2(R)-(isobu tyl-

p r op ion yl)-^L-ter t-leu cin e N-Meth yla m id e (6k k k ). Com-

pound 6k k k was prepared by subjecting compound 5ooo to

general procedure G. Yield ) 55%. TLC: R_f) 0.56 (CHCl₃/

MeOH/H₂O, 150/45/5). Purity: >96% (HPLC method J ). ¹H

NMR (300 MHz, DMSO): δ 0.90 (dd, 6H), 0.95-1.05 (m, 1H),

1.00 (s, 9H), 1.40-1.60 (m, 2H), 2.70 (d, 3H), 2.75-2.85 (m,

1H), 3.80 (t, 1H), 4.30 (d, 1H), 5.50 (d, 1H) 7.60 (d, 1H), 8.00

(m, 1H), 9.00 (s, 1H), 10.70 (s, 1H). Anal. (C₁₅H₂₉N₃O₅) C, H,

N.

3-(Hyd r oxyca r bon yl)-2(R)-(isobu tylp r op ion yl)-^L-tr yp -

top h a n N-Meth yla m id e (7a ). Compound 7a was prepared

by subjecting compound 5eee to general procedure I. Yield )

72%. Purity: >99% (HPLC method A). ¹H NMR (300 MHz,

DMSO): δ 0.8 (dd, 6H), 1.1 (m, 1H), 1.35 (m, 2H), 2.15 (dd,

1H), 2.30 (dd, 1H), 2.55 (d, 3H), 2.7 (m, 1H), 2.95 (dd, 1H), 3.1

(dd, 1H), 4.45 (m, 1H), 6.95 (t, 1H), 7.05 (t, 1H), 7.1 (d, 1H),

7.3 (d, 1H), 7.55 (d, 1H), 7.75 (m, 1H), 8.0 (d, 1H), 10.8 (s, 1H).

Anal. (C₂₀H₂₇N₃O₄‚0.5H₂O) C, H; N: calcd, 10.99; found, 10.52.

3-(H yd r oxyca r b on yl)-2(R )-(b u t ylp r op ion yl)-L-t r yp -

top h a n Meth yla m id e (7b). Compound 7b was prepared by

subjecting compound 5fff to general procedure I. Yield ) 63%.

3-(H yd r oxyca r b on yl)-2(R )-(h e xylp r op ion yl)-^L-t r yp -

top h a n Meth yla m id e (7c). Compound 7c was prepared by

subjecting compound 5h h h to general procedure I. Yield )

55%.

3-(H yd r oxyca r b on yl)-2(R )-(oct ylp r op ion yl)-^L-t r yp -

top h a n Meth yla m id e (7d ). Compound 7d was prepared by

subjecting compound 5jjj to general procedure I. Yield ) 76%.

3-(Hyd r oxyca r bon yl)-3(S)-h yd r oxy-2(R)-(isobu tylp r o-

p ion yl)-^L-tr yp top h a n N-Meth yla m id e (7e). Compound

27a (2.19 g, 5.10 mmol) was dissolved in THF (20 mL) and

diluted with H₂O (25 mL) and 6 N HCl (5 mL). The reaction

mixture was stirred at room temperature for 5 h, after which

it was concentrated to 50% its original volume. The resulting

solution was lyophilized giving compound 7e (2.00 g, 100%).

3-(Hyd r oxyca r bon yl)-3(S)-h yd r oxy-2(R)-(isobu tylp r o-

p ion yl)-^L-ter t-leu cin e N-Meth yla m id e (7f). Compound 27b

(4.17 g, 11.71 mmol) was dissolved in THF (50 mL), and 2 N

HCl (50 mL) was added. The reaction mixture was stirred at

3-[N-[(Met h oxyca r b on yl)m et h oxy]ca r b a m oyl]-2(R)-

(isobu tylp r op ion yl)-^L-tr yp top h a n N-Meth yla m id e (8c).

Compound 8c was prepared by reacting compound 6a with

methyl bromoacetate according to general procedure H. Yield

) 35%. Purity: >90% (HPLC method A). ¹H NMR (300 MHz,

DMSO): δ 0.75 (dd, 6H), 1.0 (m, 1H), 1.35 (m, 2H), 1.95-2.15

(m, 2H), 2.5 (bd, 3H), 2.7 (m, 1H), 2.95 (dd, 1H), 3.1 (dd, 1H),

3.7 (bs, 3H), 4.45 (m, 3H), 6.95-7.15 (m, 3H), 7.35 (d, 1H), 7.6

(d, 1H), 7.8 (d, 1H), 8.0 (d, 1H), 10.8 (s, 1H), 11.3 (s, 1H). Anal.

(C₂₃H₃₂N₄O₆) C, H, N.

N -(4-Me t h y lp e n t a n o y l)-(S )-4-b e n zy l-2-o x a zo lid i-

n on e (14a ). Compound 14a was prepared by coupling 4-me-

thylpentanoyl chloride, 13a , with (S)-4-benzyl-2-oxazolidinone

according to general procedure A. Yield ) 100%.

N-Hexa n oyl-(S)-4-ben zyl-2-oxa zolid in on e (14b). Com-

pound 14b was prepared by coupling hexanoyl chloride, 13b,

with (S)-4-benzyl-2-oxazolidinone according to general proce-

dure A. Yield ) 97%. TLC: R_f) 0.65 (30% EtOAc/hexane).

N-Octa n oyl-(S)-4-ben zyl-2-oxa zolid in on e (14c). Com-

pound 14c was prepared by coupling octanoyl chloride, 13c,

with (S)-4-benzyl-2-oxazolidinone according to general proce-

dure A. Yield ) 99%. TLC: R_f) 0.70 (30% EtOAc/hexane).

N-Deca n oyl-(S)-4-ben zyl-2-oxa zolid in on e (14d ). Com-

pound 14d was prepared by coupling decanoyl chloride, 13d ,

with (S)-4-benzyl-2-oxazolidinone according to general proce-

dure A. Yield ) 95%. TLC: R_f) 0.55 (30% EtOAc/hexane).

N-[2(R)-(ter t-Bu tylcar boxym eth yl)-4-m eth ylpen tan oyl]-

(S)-4-ben zyl-2-oxa zolid in on e (15a ). Compound 15a was

prepared by subjecting compound 14a to general procedure

B. Yield ) 89%.

N-[2(R)-(ter t-Bu tylcar boxym eth yl)h exan oyl]-(S)-4-ben -

zyl-2-oxa zolid in on e (15b). Compound 15b was prepared by

subjecting compound 14b to general procedure B. Yield )

91%. de ) 94%. TLC: R_f) 0.5 (10% EtOAc/hexane).

N-[2(R)-(ter t-Bu tylca r boxym eth yl)octa n oyl]-(S)-4-ben -

zyl-2-oxa zolid in on e (15c). Compound 15c was prepared by

subjecting compound 14c to general procedure B. Yield ) 93%.

de ) 96%. TLC: R_f) 0.5 (10% EtOAc/hexane).

N-[2(R)-(ter t-Bu tylca r boxym eth yl)d eca n oyl]-(S)-4-ben -

zyl-2-oxa zolid in on e (15d ). Compound 15d was prepared by

subjecting compound 14d to general procedure B. Yield )

72%. de ) 92%. TLC: R_f) 0.5 (10% EtOAc/hexane).

2,2-Dim e t h yl-4-oxo-5(R )-(ca r b oxym e t h yl)-1,3-d iox-

ola n e (17). D-Malic acid (16, 24.97 g, 186.20 mmol) was

suspended in CH₂Cl₂(250 mL) and 2,2-dimethoxypropane

(68.69 mL, 558.60 mmol). PTSA (0.35 g, 1.86 mmol) was

added, and the reaction mixture was stirred at room temper-

ature for 4 h. The resulting solution was filtered through silica

gel (50% EtOAc/hexane) and concentrated to dryness giving

the desired product (17, 29.04 g, 90%) as colorless crystals.

Matrix Metalloproteinase Inhibitors

J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2 221

2,2-Dim eth yl-4-oxo-5(R)-(m eth oxyca r boxym eth yl)-1,3-

d ioxa la n e (18). Compound 18 was prepared by subjecting

compound 17 general procedure J (solvent ) Et₂O). Yield )

94%. TLC: R_f) 0.56 (50% EtOAc/hexane).

(R)-2-Hydr oxy-3-(m eth oxycar bon yl)pr opion ic Acid (19).

Compound 18 (19.40 g, 103.19 mmol) was dissolved in THF

(100 mL), and 1 N HCl (100 mL) was added. The reaction

mixture was stirred at room temperature for 1 h, after which

it was concentrated to 50% its original volume. After the

resulting solution was saturated with NaCl, the product was

extracted with EtOAc (12 × 50 mL). The combined organic

extracts were dried over anhydrous MgSO4, filtered, and

concentrated to provide compound 19 (14.62 g, 96%) as a light

yellow oil.

(R)-2-H yd r oxy-3-(m et h oxyca r b on yl)p r op ion ic Acid

Ben zyl Ester (20). Compound 19 (3.40 g, 22.97 mmol) was

dissolved in DMF (34 mL), and K₂CO₃(6.35 g, 45.95 mmol)

was added followed by benzyl bromide (3.00 mL, 25.27 mmol).

The reaction mixture was stirred at room temperature for 1

h, after which it was diluted with EtOAc (150 mL). The

resulting mixture was washed with H₂O (4 × 30 mL) and brine

(30 mL). After being dried over anhydrous MgSO₄, the organic

phase was filtered and concentrated to dryness. The residue

was purified on silica gel (25% EtOAc/hexane), giving com-

pound 20 (3.15 g, 58% yield) as a light yellow oil. TLC: R_f)

0.48 (50% EtOAc/hexane).

(R)-2-(Isop r op yloxy)-3-(m et h oxyca r b on yl)p r op ion ic

Acid Ben zyl Ester (21a ). Compound 20 (3.15 g, 13.24 mmol)

was dissolved in 2-bromopropane (15 mL), and Ag₂O (3.15 g)

was added. The reaction was stirred at 50 °C for 48 h, after

which it was filtered through Celite. The filtrate was concen-

trated to dryness, and the residue was purified on silica gel

(50% EtOAc/hexane), giving compound 21a (1.92 g, 52%) as a

colorless oil. TLC: R_f) 0.33 (15% EtOAc/hexane).

(R)-2-(P en tyloxy)-3-(m eth oxyca r bon yl)p r op ion ic Acid

Ben zyl Ester (21b). Compound 20 (3.05 g, 12.82 mmol) was

dissolved in 1-iodopentane (13 mL), and Ag₂O (3.05 g) was

added. The reaction was stirred at 80 °C for 48 h, after which

it was filtered through Celite. The filtrate was concentrated

to dryness, and the residue was purified on silica gel (5%

EtOAc/hexane), giving compound 21b (1.42 g, 36%) as a

colorless oil. TLC: R_f) 0.42 (15% EtOAc/hexane).

(2S,3R)-3-Meth a llyl-2-h yd r oxysu ccin ic Acid Dim eth yl

Ester (23). Dimethyl ^L-mallate (22, 6.31 mL, 47.61 mmol)

was dissolved in THF (150 mL) and cooled to -78 °C under

argon. LDA (2 M solution, 47.61 mL, 95.21 mmol) was added

over 5 min, and the reaction mixture was stirred from -78 to

-20 °C over 2 h. After the mixture was cooled to -78 °C,

methallyl bromide (6.00 mL, 59.51 mmol) was added. The

reaction mixture was allowed to warm to -5 °C over 5 h, after

which it was quenched with saturated NH₄Cl (100 mL). The

resulting mixture was diluted with EtOAc (400 mL), and the

layers were separated. The organic phase was washed with

1 N HCl (3 × 50 mL), saturated NaHCO₃(3 × 50 mL), and

brine (50 mL). After being dried over MgSO₄, the organics

were filtered and concentrated to dryness. Purification of the

residue on silica gel (30% EtOAc/hexanes) gave compound 23

(4.48 g, 44%). TLC: R_f) 0.36 (30% EtOAc/hexane).

(2S,3R)-3-Isobu t yl-2-h yd r oxysu ccin ic Acid Dim et h yl

Ester (24). 10% Pd/C (1.96 g) was placed under vacuum, and

MeOH (50 mL) was added. Compound 23 (6.99 g, 32.36 mmol)

was dissolved in MeOH (50 mL) and added, via cannula, to

the Pd/C. The mixture was degassed under vacuum and

stirred under H₂for 17 h. Filtration of the reaction through

Celite and concentration under vacuum gave compound 24

(6.93 g, 98%), which was used without further purification.

TLC: R_f) 0.37 (30% EtOAc/hexane).

(2S,3R)-3-Isobu tyl-2-h yd r oxysu ccin ic Acid (25). Com-

pound 24 (6.93 g, 31.79 mmol) was dissolved in MeOH (64 mL),

and 2 N NaOH (64 mL) was added. The reaction mixture was

stirred at room temperature for 9 h after which, the volume

was reduced by 60% under vacuum. The residue was acidified

to pH ) 1 with 6 N HCl and saturated with NaCl. The product

was extracted with EtOAc (6 × 50 mL). The organics were

dried over MgSO₄, filtered, and concentrated to dryness, giving

compound 25 (6.12 g, 100%). [Note: Crystals may precipitate

at pH ) 4-5. Do not isolate these crystals. They are probably

succinic anhydride products and will not react in the next step.

At pH ) 1, all solids are dissolved and the only species should

be the desired dicarboxylic acid.]

2(R)-[2,2-Dim eth yl-4-oxo-1,3-5(S)-Dioxola n yl]-4-Meth -

ylp en ta n oic Acid (26). Compound 25 (6.12 g, 32.21 mmol)

was dissolved in dimethoxypropane (60 mL), and TsOH (0.61

g, 3.22 mmol) was added. The reaction mixture was stirred

at room temperature for 2.5 h, after which it was concentrated

to dryness. The residue was diluted with EtOAc (100 mL) and

washed with H₂O (3 × 20 mL) and brine (20 mL). The organics

were dried over MgSO₄, filtered, and concentrated to dryness,

giving compound 26 (6.14 g, 83%). [This reaction turns dark

red. Some discoloration may be avoided by first filtering the

reaction through a plug of silica gel and then concentrating

the mixture as described. TLC: R_f) 0.64 (CHCl₃/MeOH/H₂O,

150/45/5).

2(R)-[2,2-Dim eth yl-4-oxo-1,3-(5S)-d ioxola n yl]-4-(m eth -

ylp en ta n oyl)-^L-tr yp top h a n N-Meth yla m id e (27a ). Com-

pound 26 (4.59 g, 19.96 mmol) was dissolved in CH₂Cl₂(85

mL), and HOBT (2.97 g, 21.95 mmol), EDC (5.74 g, 29.93

mmol), and NMM (3.29 mL, 29.93 mmol) were sequentially

added. The reaction mixture was stirred at room temperature

for 15 min, after which compound 3a (5.55 g, 21.95 mmol) was

added. The reaction mixture was stirred at room temperature

for 2 h, after which it was concentrated to dryness. The

residue was diluted with EtOAc (100 mL) and sequentially

washed with 1 N HCl (3 × 20 mL), saturated NaHCO₃(3 ×

20 mL), and brine (20 mL). The organics were dried over

anhydrous MgSO₄, filtered, and concentrated. The residue

was purified on silica gel (50% EtOAc/hexane), giving com-

pound 27a (2.19 g, 26%) as a colorless solid. TLC: R_f) 0.62

(50% EtOAc/hexane).

2(R)-[2,2-Dim eth yl-4-oxo-1,3-(5S)-d ioxola n yl]-4-(m eth -

ylp en ta n oyl)-^L-ter t-leu cin e N-Meth yla m id e (27b). Com-

pound 27b was prepared by coupling compound 3bbb with

compound 26 according to general procedure F. Yield ) 44%.

TLC: R_f) 0.34 (50% EtOAc/hexane).

En zym e Assa ys. En zym es a n d Activa tion Con d ition s.

A 96-well plate fluorogenic assay was used to measure the

relative potency of a series of matrix metalloproteinase inhibi-

tors (MMPIs) against a variety of matrix metalloproteinases

MMPs. All enzymes were activated with a freshly prepared

10 mM stock of 4-aminophenyl mercuric acetate (APMA,

Aldrich) in 20 mM NaOH. Optimal activation conditions for

each of the MMPs were as follows: neutrophil collagenase and

stromelysin required a 1.5 h incubation at 37 °C using 2.4 mM

and 1 mM APMA, respectively; 72 kDa and 92 kDa gelatinases

were incubated at 37 °C with 0.9 mM APMA for 1 and 2 h,

respectively.

Su bstr a te a n d Ca libr a tin g Sta n d a r d . Stock solutions

(10 mM) of the fluorogenic peptide MMP substrate (Mca-Pro-

Leu-Gly-Leu-Dpa(Dnp)-Ala-Arg-NH₂) and the cleavage product

(Mca-Pro-Leu-NH₂) (Bachem Bioscience, Inc.) were prepared

in dimethylformamide. The cleavage product was used to

convert arbitrary fluorescent units to a concentration (mmol/

liter). For assay measurements, the MMP substrate was

diluted to a final concentration of 10 µM with 50 mM Tris pH

7.5, 150 mM NaCl, and 20 mM CaCl₂‚2H₂O (buffer A) in

polystyrene tubes (Falcon no. 2017). Nonspecific binding of

the substrate was observed if glass or other plastic tubes were

substituted for polystyrene.

Equ ip m en t a n d In str u m en ta tion . Assays were per-

formed in white flat-bottomed 96-well plates (Dynatech) coated

for 30 min with 1% BSA, 0.01% sodium azide in PBS to prevent

adsorption of the MMPs which was observed with uncoated

or siliconized plates (data not shown). Measurements were

determined using a Titertek Fluoroskan II 96-well plate

fluorometer (MTX Lab Systems, Inc.) equipped with 325 nm

excitation and 460 nm emission filters. Data were collected

and processed using the Delta Soft II ELISA analysis program

(Bio Metallics, Inc.).

222 J ournal of Medicinal Chemistry, 1998, Vol. 41, No. 2

Levy et al.

Castellot, J . J .; Barletta, J . P.; Schultz, G. X.; Fernandez, L. A.;

Fisher, S.; Cui, T.-Y.; Foellmer, H. G.; Grobelny, D.; Holleran,

W. M. Low Molecular Weight Inhibitors in Corneal Ulceration.

Ann. N.Y. Acad. Sci. 1994, 732, 315-323.

En zym e P r ep a r a tion . Each of the MMPs was added to a

BSA-pretreated 15 mL conical tube just prior to use and

diluted with buffer A to yield a rate in the absence of inhibitor

of 0.77 (FlU/min)/mL.

(9) Holleran, W. M.; Galardy, R. E.; Gao, W. N.; Levy, D.; Tang, P.

C.; Elias, P. M. Matrix Metalloproteinase Inhibitors Reduce

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Suppression of Experimental Allergic Encephalomyelitis in the

Lewis Rat by the Matrix Metalloproteinase Inhibitor Ro31-

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Human Central Nervous System, Microglial Nodules, and

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Assa y. The assay was initiated by adding 130 uL of diluted

MMP to wells of the 96-well plate that contained 20 µL of

MMPI (diluted from 5mM in DMSO with buffer A) ranging in

concentration from 0 to 20 nM and 50 µL of a 40 µM dilution

of MMP substrate. Kinetic rates were determined at constant

dp/dt at room temperature and collected for 50 min. Using a

Dixon plot (1/v versus [I]), relative K_ivalues for each of the

MMPIs were determined using 10 µM substrate and 0-20 nM

inhibitor. The K_ivalues were calculated as [-1(x intercept)],

realizing that (1 + S/K_m) would change the value by less than

2-fold for all enzymes tested (K_mfor all enzymes tested was

>10 µM).

Ack n ow led gm en t. The authors gratefully acknowl-

edge the work of Dr. Angela P. Horne for her contribu-

tions in the NMR characterization of key compounds;

Dr. Peng Cho Tang and Mr. Asaad Nematalla for their

synthetic efforts in the preparation of early analogues;

Dr. Peter Fu¨ge´di for his discussions surrounding the

preparation of malic acid analogues; Dr. Brent Summers

for his work in developing the enzyme assay; Dr. Stu

Swiedler for his assistance in the preparation of this

manuscript; Dr. Karen Hasty (University of Tennessee)

for providing purified human recombinant neutrophil

collagenase; Dr. Henning Birkedal-Hansen (University

of Alabama) for providing purified human 72 kDa

gelatinase; Dr. Eric Howard (University of Oklahoma)

for providing purified human 72 kDa gelatinase and

human 92 kDa gelatinase/TIMP-1 complex; and Dr.

Hideaki Nagase (University of Kansas) for providing

human recombinant stromelysin.

(19) Levy, D. E.; Ezrin, A. M. Matrix Metalloproteinase Inhibitor

Drugs. Emerging Drugs: The Prospects for Improved Medicines

1997, 2, 205-230.

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(21) Dhanaraj, V.; Ye, Q. Z.; J ohnson, L. L.; Hupe, D. J .; Ortwine, D.

F.; Dubar, J . B.; Rubin, J . R.; Pavlovsky, A.; Humblet, C.;

Blundell, T. L. X-ray Structure of a Hydroxamate Inhibitor

Complex of the Stromelysin Catalytic Domain and its Compari-

son with Members of the Zinc Metalloproteinase Superfamily.

Structure 1996, 4, 375-386.

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Broadhurst, M. J .; Brown, P. A.; J ohnson, W. H.; Murray, E. J .

Structure of the Catalytic Domain of Human Fibroblast Colla-

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Su p p or tin g In for m a tion Ava ila ble: ¹H NMR spectral

data for intermediate compounds 1c, 1n , 1o, 2b-ccc, 3b-

ccc, 4c-h , 5b-ooo, 7b-f, 14a -d , 15b-d , 17-20, 21a ,b, 23-

26, 27a ,b (40 pages). Ordering information is given on any

current masthead page.

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J M970494J

Article Doi

Matrix metalloproteinase inhibitors: A structure-activity study

DOI: 10.1021/jm970494j

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Full text of DOI:10.1021/jm970494j

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