Higher order iminodiacetic acid libraries for probing protein-protein interactions

BIOORGANIC &

MEDICINAL

CHEMISTRY

Bioorganic & Medicinal Chemistry 6 (1998) 1347±1378

Higher Order Iminodiacetic Acid Libraries for Probing

Protein±Protein Interactions

Dale L. Boger,* Joel Goldberg, Weiqin Jiang, Wenying Chai, Pierre Ducray,

Jae Kyoo Lee, Rachel S. Ozer and Carl-Magnus Andersson

Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road,

La Jolla, California 92037, USA

Received 24 June 1998

AbstractÐFull details of the preparation of iminodiacetic acid diamide dimer (2040 compounds), trimer (560 com-

pounds), and tetramer (1596 compounds) libraries by multistep convergent solution-phase synthesis for studying pro-

tein±protein interactions are provided. The libraries were assembled in a format providing small 8±10 compound

mixtures and the deconvolution of many of the small mixtures to identify screening leads by resynthesis of the indivi-

dual components have been conducted for 320 of the individual compounds to date. A representative example of the

subsequent exploration of the structure±activity relationships for an identi®ed receptor binding antagonist (200 addi-

tional individual compounds) and steps taken for potential elaboration to a receptor dimerization agonist are de®ned

Introduction

such receptor or protein dimerization and representative

examples are provided in Table 2 for the cytokine

receptor superfamily. That many of these receptors and

proteins appear to bind their ligands using small clusters

of residues for the majority of their binding inter-

action^7±9has led to the expectation that small molecules

may be capable of inducing dimerization and triggering

a receptor response. Although the generation of detailed

knowledge concerning the dimerization modes and

ligand binding domains of single transmembrane

domain receptors will provide a basis for the design of

functional agonists as well as ligand antagonists, the

noncontiguous and multiple binding domains involved

in the protein±protein and ligand±protein interactions

make it dicult to assess the dimerization mode or

ligand binding domains in the absence of three-dimen-

sional structural information. This is especially true

considering the size of the typical endogenous protein

ligands which themselves contain noncontiguous bind-

ing domains which interact with both subunits of the

dimerized receptor.⁹Our interest in combinatorial

chemistry rested on its potential to provide candidate

leads for promoting receptor activation by dimerization.

This interest in studying receptor dimerization and acti-

vation coupled with the potential of utilizing a single

approach for the discovery of antagonists and their

Ligand-induced receptor and protein dimerization or

oligomerization has emerged as a general mechanism for

signal transduction^1,2and important members of many

receptor superfamilies are activated by such a process.

These include protein tyrosine kinase receptors (homo-

or heterodimerization),³class

I cytokine receptors

(homo- or heterodimerization),⁴serine/threonine kinase

receptors (hetero-oligomerization),⁵and members of the

TNF-receptor family (trimerization), Table 1.⁶Within

the cytokine receptor superfamily, the most extensively

studied examples are the human growth hormone

(hGHr),⁷prolactin (PRLr)⁸and erythropoietin recep-

tors (EPOr),⁹which form homodimers upon binding

their endogenous protein ligands. Similarly, intracellular

signal transduction often proceeds by protein±protein

homo- or heterodimerization and important examples

include activators of transcription (e.g. Myc±Max

dimerization, JAK homo- and heterodimerization,

STAT homo- and heterodimerization).^10±12

Important therapeutic applications may emerge from

either the development of agonists or antagonists of

*Corresponding author. Tel: 619-784-7522; Fax: 619-784-7550.

PII: S0968-0896(98)00128-X

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D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

Table 1. Class I cytokine receptors

Family

Examples

Activation characteristics

homodimers

GH receptor

IL-3 receptor

IL-6 receptor

IL-2 receptor

GHR, EPOR, PRLR, G-CSFR

IL-3R, GM-CSFR, IL-5R

heterodimeration with b_C

heterodimerization with gp130

IL-6R, LIFR, CNTFR, IL-11R

IL-2Ra, IL-2Rb, IL-4R, IL-7R

heterodimerization with IL-2Rg

Protein±tyrosine kinase receptors activated by dimerization or oligomerization

Family

Examples

PDGF receptor

EGF receptor

FGF receptor

IGF receptor

HGF receptor

VEGF receptor

Neutrophin

PDGFR-a, PDGFR-b, SCFR, CSF-R, Fik-2

EGFR (erbB), erbB-2 (Neu), erbB-3, erbB-4

FGFR-1, FGFR-2, FGFR-3. FGFR-4

Insulin R, IGF-1R

HGFR (Met), MSPR (Ron)

Flt-1, Flt-2 (KDR)

Trk, TrkB, TrkC

Eph receptor

Eph, Elk, Eck, Cck5, Sek, Eck, Erk

Abbreviations: R, receptor; GH, growth hormone; EPO, erythropoietin; PRL, prolactin; IL, interleukin; LIF, leukemia inhibitory

factor; CNTF, ciliary neurotrophic factor; PDGF, platelet-derived growth factor; SCF, stem cell factor; CSF, colony-stimulating

factor; EGF, epidermal growth factor; FGF, ®broblast growth factor, IGF, insulin-like growth factor; HGF, hepatocyte growth fac-

tor; MSP, microphage-stimulating protein; VEGF, vascular endothelial growth factor; FN, ®bronectin.

Table 2. Approved or potential therapeutic applications of cytokine agonists and antagonists

Cytokine

Agonist

Antagonist

EPO

TPO

anemias, selective blood donation

thrombocytopenia

cancer

cancer, leukemia

IL-2

IL-3

histoincompatibility

leukemia

allergy

leukopenia, myeloid reconstitution

in¯ammation, cancer

thrombocytopenia

IL-4

IL-6

cancer, osteoporosis, in¯ammation

IL-11

IL-12

G-CSF

GM-CSF

IFN a/b

IFN g

thrombocytopenia

cancer, infections

histoincompatibility, autoimmunity

leukemia

neutropenia, myeloid reconstitution

leukopenia, myeloid reconstitution

cancer, viral infections, autoimmunity

chronic granulonatous disease, infections

in¯ammation

in¯ammation, autoimmunity

conversion to agonists¹³was one important element

underlying our pursuit of solution-phase combinatorial

chemistry at a time when solid-phase techniques were

considered most useful.

of our own eorts on the development of a multistep

solution-phase parallel synthesis of chemical libraries,¹⁷

the single step solution-phase synthesis of mixture

libraries was detailed by at least three groups.^18±20In

addition to continued advances in this work, progress in

using solution-phase multicomponent reactions for gen-

erating combinatorial mixtures,^21,22the use of resin

capture as well as resin scavenger techniques²³including

ion-exchange resins for solid-phase acid±base extrac-

tions,^17,23¯uorous phase extractions,²⁴and liquid-phase

polymers²⁵have been described.²⁶Our eorts focused

on the development of a technically non-demanding

multistep, solution-phase strategy for the preparation of

chemical libraries which relied on the removal of excess

reactants and reagents by liquid±liquid or liquid±solid

extractions.¹⁷The approach was shown to dependably

Combinatorial chemistry, initially pursued with peptide

and oligonucleotide libraries, has undergone rapid

development providing a new paradigm for drug dis-

covery.¹⁴Perhaps as a consequence of the extension

from linear peptide and oligonucleotide synthesis, the

majority of applications have relied on linear solid-

phase synthesis and methodological advances continue

to extend common synthetic transformations to polymer-

supported versions.¹⁵

A less commonly employed

approach is the development of protocols for solution-

phase combinatorial synthesis.¹⁶Preceding the disclosure

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1349

deliver pure individual compounds in large quantities

(50±150 mg), and libraries of >1000 individual mem-

bers were assembled in initial eorts.¹⁷It has been since

implemented on scales producing 50±150 mg of the

®nal materials in formats for the parallel synthesis of

individual pure compounds,¹⁷for modest sized librar-

ies composed of small mixtures^27±29(1000±10,000

member libraries, 10±100 compounds/mixture), or

combinatorially assembled to provide larger compound

libraries^30,31(25,000±450,000 member libraries, 25,000±

450,000 compounds/mixture) allowing its compatibility

with any screening objective or protocol. Since the

libraries are produced on a relatively large scale, they

may be repeatedly dispensed for screening without

depletion of the growing collection. These features along

with its technically non-demanding implementation are

among its greatest attributes.

Figure 1.

immediate precursor 3 is straightforward and the

screening assays are applied to a modest mixture of 10

compounds. In addition to the advantages associated

with the testing of a modest mixture of 10 compounds,

the variability within each sublibrary was only in the

nature of the linker. This might potentially minimize the

false positive or negative screening results that accom-

pany the testing of mixtures of compounds and permit

the simultaneous examination of a range of linkers.

Herein, we summarize its extension to the preparation

of modest sized libraries suitable for probing protein±

protein interactions. This entailed the dimerization,

trimerization, or tetramerization via sequential dimer-

ization of iminodiacetic acid diamides using symmetrical

carboxylic acids.^27,28These complement

a related

approach we detailed that utilizes the ole®n metathesis

reaction to join iminodiacetic acid diamides and rando-

mize the length of the linking tether.^29±31In this latter

case, we have also disclosed the twofold dimerization

linkage of iminodiacetic acid diamides to provide higher

order libraries containing up to eight variable groups

and the accompanying technique of deletion synthesis

deconvolution³¹to identify lead compounds derived

from unsymmetrical dimerizations. Unlike the linear

divergent synthesis of libraries derived from solid-phase

synthesis, the convergent dimerizations are especially

suited for solution-phase synthesis and would be pre-

cluded by typical solid-phase techniques where the

combining components are on mutually exclusive solid

phases (Fig. 1).

Reaction of N-BOC-iminodiacetic acid with the water

soluble coupling reagent EDCI (1±1.05 equiv, DMF,

25 ^ꢀC, 1 h),³²and subsequent in situ anhydride ring-

opening with the six primary amines A1±A6 (R¹NH₂, 1

equiv, DMF, 25 ^ꢀC, 12 h, 64±99%) was conducted on

20 mmol scales and provided approximately 7 g of the

monoamides 3 in superb yields (avg=90%, Table 3).

Simply washing the crude product diluted in EtOAc

with aqueous acid (10% aqueous HCl) served to remove

unreacted R¹NH₂, EDCI and its reaction byproducts

and provided the pure monoamides (ꢁ95% pure).

Each of the six monoamides 3 was partitioned into 10

portions with an additional larger portion retained for

archival and resynthesis purposes. Each portion was

treated with the 10 amines (B1±B10, 1.1 equiv) and

PyBOP (1.1 equiv, 2±2.2 equiv i-Pr₂NEt, DMF, 25 ^ꢀC,

16 h, 7±99%) to aord 60 individual diamides 4 which

were puri®ed by sequential acid (10% aqueous HCl),

base (saturated aqueous NaHCO₃), and saturated

aqueous NaCl extractions from EtOAc to remove

reagent-derived reaction byproducts, unreacted starting

material, and PyBOP. Each reaction was conducted on

a 1.75 mmol scale corresponding to approximately

600 mg of 3 and provided 4 in yields that ranged from

7±100% (Table 3, avg=53%). The lower yielding reac-

tions were compromised by the water solubility of the

products. Irrespective of the reaction eciency or product

recovery and without deliberate reaction optimization,

Dimerization of iminodiacetic acid diamides. In a design

that minimizes the number of chemical reactions, that

maximizes the diversity impact and that provides a

convenient screening/deconvolution format, a library of

600 compounds was constructed in a 6Â10Â10 matrix

with the ®nal diversi®cation being accomplished in one

reaction to provide a mixture of 10 compounds con-

taining variations in only the dicarboxylic acid linking

domain (Fig. 2). For the three-step synthesis, this

required six amines (R¹NH₂, A1±A6), 10 amines (R²NH₂,

B1±B10), and 10 dicarboxylic acids (HO₂C-X-CO₂H,

C1±C10), and the conduct of 126 reactions to produce 60

sublibraries each containing 10 compounds containing

variations only in the dicarboxylic acid linking domain.

Deconvolution of such a mixture by resynthesis of the

individual components from archived samples of the

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D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

the purities of the resulting diamides were uniformly

satisfactory (ꢁ90±95%) and the identities of products

1

were con®rmed by matrix characterization (HRMS, H

NMR and IR).

We brie¯y examined alternatives to PyBOP for the sec-

ond coupling and found that EDCI and BOPCl were less

eective than PyBOP (Scheme 1). In addition, although

polymersupported EDCI³³was ineective at promoting

the second coupling to provide the diamides 4, it was

found to constitute a convenient alternative for the in

situ conversion of N-BOC-iminodiacetic acid (2) to the

anhydride 1 for the ®rst functionalization reaction with

the generation of 3 (A3, 68%; DMF, 25 ^ꢀC, 20 h).

The assembly of the library of 600 compounds entailed

60 coupling reactions each composed of one iminodi-

acetic acid diamide 4 and an equimolar mixture of 10

dicarboxylic acids (C1±C10) producing 60 sublibraries

of 10 compounds each containing variations only in the

linking dicarboxylic acid. This was accomplished by

acid-catalyzed deprotection of 4 (4 N HCl±dioxane,

25 ^ꢀC, 2 h) conducted on each of the individual 60

iminodiacetic acid diamides (A1B1±A6B10, 0.15 mmol)

followed by coupling (0.15 mmol PyBrOP, 0.45 mmol

i-Pr₂NEt, DMF, 25 ^ꢀC, 12 h, 9±99%) of the crude amine

hydrochloride salt with an equimolar mixture of the

dicarboxylic acids C1±C10 (0.005 mmol each, 0.05 mmol

total, 0.67 equiv). The use of the secondary amine in

excess for an extended reaction time insured the com-

plete consumption of the limiting diacid linkers and the

near equimolar generation of each compound. Puri®cation

by sequential aqueous acid and aqueous base extrac-

tions served to remove the unreacted excess secondary

amines derived from AXBX, any unreacted dicarboxylic

acids C1±C10 as well as any monocarboxylic acid con-

taminant derived from partial reactions of C1±C10, the

excess reagents (PyBrOP, i-Pr₂NEt) and their reaction

Figure 2.

Scheme 1.

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1351

Table 3. Yields (%) of 3 and 4 and isolated amounts (mg) and yields (%) of the 60 ®nal sublibraries 5 (AXBXC1±10)

3

4

A1, 98 A2, 99 A3, 64 A4, 99

A5, 99

A6, 80

A1 A2 A3 A4 A5 A6

5

A1

A2

A3

A4

A5

A6

B1 90 95

B2 12 17

a

75 81 100

9 18 27 18

B1

B2

B3

B4

B5

B6

B7

B8

B9

B10

49 mg, 99%

10 mg, 24%

36 mg, 79%

36 mg, 74%

47 mg, 99%

18 mg, 44%

11 mg, 29%

7 mg, 13%

20 mg, 42%

52 mg, 91%

49 mg, 99%

13 mg, 29%

46 mg, 93%

39 mg, 76%

50 mg, 99%

58 mg, 66%

28 mg, 66%

26 mg, 47%

10 mg, 20%

48 mg, 78%

48 mg, 99%

37 mg, 84%

20 mg, 41%

22 mg, 46%

49 mg, 99%

9 mg, 21%

18 mg, 46%

21 mg, 40%

10 mg, 20%

27 mg, 45%

49 mg, 99%

10 mg, 21%

4 mg, 9%

50 mg, 99%

14 mg, 32%

26 mg, 56%

28 mg, 57%

31 mg, 59%

12 mg, 27%

11 mg, 26%

18 mg, 33%

18 mg, 37%

40 mg, 68%

36 mg, 74%

6 mg, 13%

38 mg, 59%

36 mg, 73%

42 mg, 82%

29 mg, 66%

14 mg, 34%

20 mg, 37%

52 mg, 88%

21 mg, 41%

B3 81 81 84 67 50 97

B4 89 68 40 56 64 89

37 mg, 73%

50 mg, 99%

22 mg, 50%

21 mg, 50%

22 mg, 39%

19 mg, 38%

33 mg, 53%

B5 97 96

B6 57 85 50 43 46 86

B7 13 15 19 13 36

a

68 92 100

7

B8 43 32 18 26 33 50

B9 20 27 12 16 12 42

B10 99 97 100 72 91 100

^ahygroscopic.

byproducts. Using this protocol, each of the 60 sub-

libraries of 10 compounds was produced in yields ran-

ging from 9±99% (avg=57%) in amounts ranging from

4±52 mg (Table 3). Irrespective of the conversion, the

extractive puri®cation coupled with the scale provided

the libraries in high purity (ꢁ90%) and in sucient

quantity suitable for direct broad screening in a variety

of assays. Matrix characterization of the 60 sublibraries

with NaCl improved the mass balance recovery and

eectively removed the excess amine reactants and

1

by MS and H NMR con®rmed the constitution of the

mixtures and the detailed evaluation of the sublibrary

A2B6C1±10 established its integrity as described below.

1

Although H NMR was not especially useful at quanti-

tating the mixture components and only marginally

useful at establishing the mixture identity, it was eec-

tive at identifying and quantitating contaminate

secondary amine (AXBX), reagents (PyBrOP, i-Pr₂NEt),

and reagent-derived reaction byproducts ensuring the

integrity of the extraction puri®cation.

That this protocol would produce the sublibraries satis-

factorily was ®rst demonstrated by examining the indi-

vidual and mixture couplings of 6 and 7, and with the

individual and mixture construction of the sublibrary

A2B6C1±C10. Although PyBOP and EDCI proved less

satisfactory for promoting the individual and mixture

couplings of 6 and 7 with C1±C10, PyBrOP³⁴smoothly

provided the linked dimers (Scheme 2). Excess i-Pr₂NEt

was employed to neutralize any residual acid remaining

after BOC deprotection, and conducting the reaction

with excess AXBX (0.3 mmol) versus dicarboxylic acid

(0.1 mmol, 0.67 equiv) for 8±24 h in the presence of

PyBrOP (0.3 mmol) and i-Pr₂NEt (0.9 mmol) led to

satisfactory conversions with the complete consumption

of the C1±C10 dicarboxylic acid linker. Conventional

extractive workup with aqueous 10% HCl to remove

unreacted AXBX and i-Pr₂NEt led to occasional loss of

product due to its water solubility especially with the

more hydrophilic sublibraries. The use of either an

acidic ion exchange resin (liquid±solid extraction,

DOWEX 50WX8-400)³⁵or aqueous 20% HCl saturated

Scheme 2.

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D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

reagents. Using either of these protocols, the extractive

puri®cation provided the individual compounds and the

mixture sublibraries at an exceptional level of purity

with satisfactory recoveries.

Prior to implementing the full library synthesis, the

A2B6C1±C10 sublibrary was prepared by running each

of the 10 individual coupling reactions and the mixture

coupling reaction (Scheme 3). The conversions and

recovery (70±100%, 90% avg) as well as the purity

(ꢁ90±95%) of the individual reactions were uniformly

high and correspond nicely to the mixture coupling

reaction (95% yield, >90% purity by ¹H NMR/

HPLC). This is illustrated with the preparation of

A2B6C2 (Fig. 3) where the ¹H NMR spectra of each

of the two intermediates and the ®nal reaction product

are presented as they were obtained directly from the

reaction sequence and extraction puri®cation. Following

characterization (¹H NMR, IR, HRMS) of the separate

products (A2B6C1±A2B6C10), these were subjected to

reverse-phase HPLC separation, both separately and

after pooling in equimolar proportions. The MS estab-

lished the presence of each mixture component and

both ¹H NMR and HPLC revealed no signi®cant dif-

ferences in the reconstituted and combinatorial mix-

tures. Thus, the mixture coupling and the subsequent

extraction puri®cation were established to provide a

near equimolar mixture of the reaction products and

each of the 10 components was found to be present in

the ®nal sublibrary. In part, this may be attributed to

the choice of coupling reaction conditions that ensure

1

Figure 3. Comparison H NMR spectra (DMSO-d₆, 400 MHz)

of A2, A2B6, and A2B6C2 as isolated.

near complete consumption of the limiting diacids and

to the choice of the diacid linkers which have little dif-

ferential impact on the relative solubility of the ®nal

products.

In the course of screening the library against various

targets, the A1B10C1±C10, A2B10C1±C10, A4B10C1±

C10, A5B10C1±C10, A6B10C1±C10, A2B1C1±C10,

A4B1C1±C10, A5B4C1±C10, and A3B3C1±C10 sub-

libraries have been deconvoluted to provide the 90 indi-

vidual compounds. In addition, this initial library of 600

compounds was subsequently extended to the additional

1440 compound library illustrated in Fig. 4 enlisting a

slightly modi®ed and expanded set of 80 individual

diamides 4 (cf. Fig. 5) and their coupling with two

dierent mixture sets of dicarboxylic acids C11±C20

Scheme 3.

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1353

with symmetrical dicarboxylic acids, a library of 560

symmetrical trimers was assembled in a 8Â10Â7 matrix

with the ®nal reaction being conducted with the tri-

carboxylic acid mixture C31±C37 to provide mixtures of

seven compounds containing variations only in the linking

tricarboxylic acid domain (Fig. 5). For the three-step

synthesis, this utilized eight amines (A1±A8), 10 amines

(B1±B10), and seven tricarboxylic acids (C31±C37) in 168

reactions to produce 80 sublibraries each containing seven

compounds. The library screening is conducted with

small mixtures of seven compounds, and deconvolution

by resynthesis of the seven individual components of the

®nal mixtures from archived samples of the 80 immediate

precursors

4 is straightforward. The preceding or

simultaneous examination of the intermediate N-BOC

iminodiacetic acid diamides 4 permits, in principle, the

identi®cation of competitive binders (antagonists) that

upon trimerization might function as agonists of ligand-

induced protein homodimerization or trimerization.

Reaction of N-BOC-iminodiacetic acid (2) with EDCI

(1.0 equiv, DMF, 25 ^ꢀC, 1 h) and subsequent treatment

with A1±A8 (1 equiv, DMF, 25 ^ꢀC, 70±99%) was con-

ducted on 20 mmol scales to provide 6±10 g of each of

the eight monoamides 3 in superb yields (Table 4,

avg=89%). Simply washing the crude product diluted

with EtOAc with 10% aqueous HCl and saturated aqu-

eous NaCl served to remove unreacted amine, EDCI

and its byproducts to provide the pure monoamides

(ꢁ95% pure). Each monoamide was divided into 10

portions and treated with the 10 amines B1±B10 (1.5

equiv) and PyBOP (1±1.1 equiv, 3 equiv i-Pr₂NEt,

DMF, 25 ^ꢀC, 16 h, 44±100%) to aord the 80 diamides 4

which were puri®ed by sequential 10% aqueous HCl,

saturated aqueous NaHCO₃and saturated aqueous

NaCl extractions. Each reaction was conducted on a

1.5 mmol scale (ca. 0.5 g of monoamide) providing

1.6±0.35 g of 4 (Table 4, avg=92%) in ꢁ95% purity

independent of the reaction eciency. The ®nal step in

the preparation of the library of 560 compounds

entailed 80 coupling reactions of each diamide 4 with an

equimolar mixture of the seven tricarboxylic acids (C31±

C37) producing 80 sublibraries of seven compounds. This

was accomplished by acid-catalyzed deprotection of 4

(0.15 mmol, 4 N HCl±dioxane, 25 ^ꢀC, 3 h) followed by

coupling (0.15 mmol PyBrOP, 1.5 mmol i-Pr₂NEt,

DMF, 25 ^ꢀC, 16 h, 19±100%) of the crude amine hydro-

chloride with an equimolar mixture of the tricarboxylic

acids C31±C37 (0.005 mmol each, 0.035 mmol total, 0.7

equiv). The secondary amine was used in excess and the

reactions were run for an extended time period to

drive the couplings to completion ensuring a near

equimolar generation of each compound. Puri®cation

by sequential extractions with 10% aqueous HCl (3Â),

saturated aqueous NaHCO₃(2Â), and saturated

aqueous NaCl provided the ®nal mixtures (Table 5,

Figure 4.

and C21±C28. The former produced 80 mixtures of 10

compounds each (800 compounds) and the latter pro-

vided 80 mixtures of eight compounds each (640 com-

pounds) in average ®nal coupling yields of 65% and

63%, respectively.

Trimerization of iminodiacetic acid diamides. Com-

plementary to the approach of assembling iminodiacetic

acid diamides dimers through

a ®nal N-acylation

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D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

avg=86%, 10±34 mg) free of contaminant starting

materials, reagents and their byproducts, and any partially

coupled free carboxylic acid (ꢁ95% pure). Matrix charac-

terization of the 80 sublibraries by MS and ¹H NMR con-

®rmed the constitution of the mixtures and a comparison

of the sublibrary A1B3C31±C37 with a reconstituted mix-

ture prepared by combining an equimolar mixture of the

individual components established its integrity.

Of these mixtures, the A1B2C31±37, A1B3C31±37,

A1B9C31±37, A1B10C31±37, and A2B6C31±37 sub-

libraries have been prepared as 35 individual compounds

(deconvoluted) in the course of screening eorts to date.

Sequential dimerizations of iminodiacetic acid diamides.

An additional approach that complements our dis-

closure of a twofold dimerization of iminodiacetic acid

diamides via the ole®n metathesis reaction that ulti-

mately incorporates eight variable groups and rando-

mizes the length of the linking tether adding a ninth

degree of diversi®cation,³¹entails their twofold dimer-

ization by sequential coupling with appropriately func-

tionalized dicarboxylic acids. This is illustrated with the

preparation of the tetramers 17 derived ®rst from

dimerization of 4 with N-BOC-iminodiacetic acid (2) to

provide 16 which, following N-BOC deprotection, sets

up the second dimerization conducted with a range of

dicarboxylic acids (Scheme 4, Fig. 6). In addition to

the eight variable groups incorporated into the imino-

diacetic acid diamides, a ninth diversi®cation is incor-

porated with the second set of linking dicarboxylic

acids. A library of 1596 compounds was prepared in a

format of 168 mixtures of 10 or 8 compounds each.

Thus, 42 individual iminodiacetic acid diamides 4 were

prepared in a 3Â14³⁶format on a scale analogous to

that described previously. Deprotection of 4 (4 N HCl±

dioxane, 25 ^ꢀC, 4 h) followed by the individual

dimerization coupling of each amine hydrochloride

with N-BOC-iminodiacetic acid (1.0 equiv 2, 3 equiv

PyBrOP, 9 equiv i-Pr₂NEt, DMF, 25 ^ꢀC, 16 h, 31±100%)

provided 16. Conducting the reaction with excess amine

hydrochloride (3 molar equiv) and stoichiometry limit-

ing dicarboxylic acid insured complete dimerization

coupling and the excess starting amine, residual car-

boxylic acid, reagents, and reagent byproducts were

removed by acid/base extraction providing the 42 indi-

vidual dimers 16 (ꢁ95% pure, avg yield=81%). These

individual 42 diamide dimers (1.5 equiv/3 molar equiv),

which themselves constitute an important dimer sub-

library for antagonist screening, were deprotected (4 N

HCl±dioxane, 25 ^ꢀC, 4 h) and subsequently coupled (3

equiv PyBrOP, 9 equiv i-Pr₂NEt, DMF, 25 ^ꢀC, 16 h, 10±

97%, avg=80%) with 38 dicarboxylic acids in mixture

groupings of 10 or 8 (C1±C10, C11±C20, C21±C28, and

C41±C50) producing 168 mixtures each containing 10 or

8 compounds with mixture variations only in the last

Figure 5.

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1355

Table 4. Yields (%) of 3 and 4

3

A1, 97

A2, 99

A3, 83

A4, 90

A5, 89

A6, 92

A7, 91

A8, 70

4

A1

89

A2

100

85

A3

85

A4

100

87

A5

76

A6

100

78

A7

76

A8

100

90

B1

B2

B3

B4

B5

B6

B7

B8

B9

B10

70

86

100

78

100

76

91

79

89

99

100

79

100

90

93

100

94

100

92

75

78

85

100

93

100

98

87

96

100

44

90

75

89

100

89

90

88

100

89

100

96

100

94

100

95

100

93

100

94

100

95

100

83

100

97

100

86

100

78

100

Table 5. Yields (%) and isolated amounts (mg) of the 60 ®nal sublibraries 15 (AXBXC31-37)

5

A1

A2

A3

A4

A5

A6

A7

A8

B1

B2

B3

B4

B5

B6

B7

B8

B9

61 mg, 100% 58 mg, 100%

45 mg, 91% 68 mg, 100%

51 mg, 92% 65 mg, 100% 51 mg, 100% 42 mg, 75%

62 mg, 100% 64 mg, 100% 48 mg, 100% 74 mg, 100% 62 mg, 100% 67 mg, 100% 60 mg, 100% 50 mg, 98%

44 mg, 81%

48 mg, 85%

49 mg, 86%

55 mg, 94%

31 mg, 62%

30 mg, 59%

51 mg, 89%

52 mg, 88%

47 mg, 85%

43 mg, 75%

55 mg, 97%

56 mg, 80%

56 mg, 78% 20 mg, 36%

59 mg, 80% 22 mg, 38%

90 mg, 100% 78 mg, 100% 85 mg, 100% 80 mg, 100% 83 mg, 100% 43 mg, 100% 68 mg, 100% 57 mg, 99%

36 mg, 74% 30 mg, 63% 17 mg, 33% 39 mg, 75% 32 mg, 64% 60 mg, 84% 50 mg, 74% 10 mg, 18%

43 mg, 85% 61 mg, 100% 54 mg, 100% 51 mg, 100% 62 mg, 100% 43 mg, 84%

40 mg, 79% 53 mg, 100% 45 mg, 89% 33 mg, 100% 60 mg, 100% 32 mg, 64%

35 mg, 61% 54 mg, 92% 49 mg, 86% 54 mg, 93% 68 mg, 92% 18 mg, 30%

56 mg, 82% 77 mg, 100% 71 mg, 100% 82 mg, 100% 84 mg, 100% 57 mg, 84%

51 mg, 100% 63 mg, 100%

41 mg, 85% 54 mg, 100%

44 mg, 80%

48 mg, 91%

B10 70 mg, 100% 65 mg, 100%

linking dicarboxylic acid domain. Thus, the library pre-

paration and screening are conducted with small mix-

tures of 8 or 10 compounds, and deconvolution by

resynthesis of the individual components of a ®nal mix-

ture is straightforward from archived samples of the 42

precursors 16. Matrix full characterization of the 42

dimers 16, full characterization of representative indivi-

dual tetramers 17, and the resynthesis of the 176 indivi-

dual members of A2B4C1±10, A2B4C21±28, A2B4C41±

for a more complete de®nition of the structure±activity

relationships. One of the more extensive series we have

examined was based on the identi®cation of 5, A6B10C4

as a weak antagonist of endogenous ligand binding to a

target receptor in which the B10 subunit was critical to

observation of activity while that of A6 simply modu-

lated it (cf. Fig. 2). Based on these results, an exten-

sive series of A substitutions were examined and a more

classical detailed examination of the critical B10 subunit

was conducted simultaneously. The synthesis of 114

additional compounds containing the A substitutions

was carried out by sequential couplings to iminodiacetic

acid (Scheme 5, Fig. 7), whereas 77 compounds con-

taining B10 analogues were synthesized in one step from

diacid 20 which already contained the 4-¯uoro-

phenethylamine (A6) and isophthalic acid (C4) compo-

nents (Scheme 5, Fig. 8).

50,

A2B6C21±28,

A2B6C41±50,

A6B6C21±28,

A6B6C41±50, A7B3C11±20, A7B4C11±20, A7B4C21±28,

A7B4C41±50, A7B6C11±20, A7B6C21±28, A7B6C41±

50, A7B10C11±20, A7B14C21±28, A7B14C41±50,

A7B15C21±28, and A7B15C41±50 have been conducted

in deconvolution studies to identify screening leads. The

comparison of the reconstituted authentic equimolar

mixture with the sublibraries established the integrity of

the mixtures (A2B4C1±10, A2B4C41±50), and MS

characterization of the A2B4C1±10, A2B2⁰⁰C11±20, and

A2B4C41±50 sublibraries con®rmed the presence of all

10 components in the ®nal mixtures.

Subsequent to these studies which identi®ed 5:

A2B10C4, A5B10C4, A6B10C4, A7B10C4, A8B10C4,

A12B10C4, and A6B23C4 as viable ligand binding

antagonists, their potential conversion into agonists of

receptor dimerization and activation through chemical

dimerization was explored. This entailed adding a pro-

tected C5-aminoethoxy appendage to the isophthalic

Elaboration of lead antagonists. Follow up libraries

based upon the results of screening assays can be con-

ducted with the preparation of individual compounds

1356

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

core which allows a second dimerization of the imino-

diacetic acid diamides providing the target tetramers

(Scheme 6). The seven individual iminodiacetic acid

diamides were coupled to 22 using conditions analogous

to those previously described. Deprotection of the pri-

mary amine (4 N HCl±dioxane, 25 ^ꢀC, 2 h) was followed

by dimerization coupling (2.2 equiv of amine hydro-

chloride, 3 equiv PyBrOP, 6 equiv i-Pr₂NEt, DMF,

25 ^ꢀC, 12 h) with 10 individual dicarboxylic acids of

varied shape, length, and hydrophilicity (Fig. 9). Pur-

i®cation using acid/base extractions or solid/liquid

extractions cleanly provided the 70 individual com-

pounds in good to excellent yield (70±99%). One set of

10 products was fully characterized, and MS analysis

con®rmed the identity of the desired tetramers.

Conclusions. Complementary to our use of the ole®n

metathesis reaction to assemble higher order imino-

diacetic acid diamide libraries,^29±31their dimerization,

trimerization, or sequential dimerizations with symme-

trical carboxylic acids provide a powerful approach to

the convergent synthesis of combinatorial libraries

Scheme 4.

Figure 6.

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1357

200 mmol) dissolved in 200 mL of water. When a

homogeneous solution had formed, di-tert-butyl dicar-

bonate (25 mL, 110 mmol) was added in portions. After

stirring at 25 ^ꢀC for 72 h, the reaction mixture was

washed with Et₂O (2 Â100 mL) and the aqueous layer

was then acidi®ed with the addition of 10% aqueous

HCl (100 mL). This was extracted with EtOAc

(3Â150 mL) and the combined organic layers were

washed with saturated aqueous NaCl (2Â150 mL), and

dried (Na₂SO₄). Concentration provided 30 g of a color-

less oil, which upon addition of 30 mL of EtOAc fol-

lowed by 60 mL of hexane aorded 2 (17.2 g, 74%) as

colorless crystals: mp 135±137 ^ꢀC.

General procedure for 3: N-((tert-butyloxy)carbonyl)-N⁰-

(2-(4-methoxyphenyl)ethyl)iminodiacetic acid monoamide

(3, A2). Method A: A mixture of 2 (4.66 g, 20 mmol)

and EDCI (3.8 g, 20 mmol) in 60 mL of anhydrous

DMF was stirred for 1 h at 25 ^ꢀC. 4-Methoxyphenethyl

amine (A2, 3.0 g, 20 mmol) was added to the resulting

solution in four portions (slightly exothermic). The

reaction mixture was stirred for 20 h at 25 ^ꢀC before it

was poured into 250 mL of 10% aqueous HCl in a

separatory funnel. The product was extracted into

EtOAc (3Â200 mL) and the combined organic phases

were washed with 10% aqueous HCl (2Â200 mL), satu-

rated aqueous NaCl (2Â200 mL), dried (Na₂SO₄) and

the solvent removed in vacuo to aord 7.3 g (99%) of

1

the title compound as a white solid: H NMR (DMSO-

d₆, 500 MHz) d 8.27 (m, 1H), 7.12 (m, 2H), 6.84 (m,

2H), 3.91, 3.87, 3.83 and 3.80 (four s, 4H), 3.70 (s, 3H),

3.25 (m, 2H), 2.64 (m, 2H), 1.35 and 1.32 (two s, 9H);

IR (®lm) V_max2976, 2931, 1705, 1635, 1513, 1456, 1393,

1368, 1248, 1164, 1032, 824, 600 cm ¹; FABHRMS

(NBA±NaI) m/z 367.1862 (M+H⁺, C₁₈H₂₆N₂O₆

requires 367.1869).

Method B: A solution of 2 (0.058 g, 0.25 mmol) dis-

solved in DMF (5 mL) was added to polymer-bound

EDCI³³(0.5 g, 0.5 mmol/g, 0.25 mmol). This mixture

was allowed to stand for 1 h at 25 ^ꢀC. Tyramine (A3,

0.041 g, 0.30 mmol) was added and the mixture was

allowed to stand for 20 h. After ®ltration, the resin was

washed with DMF (5 mL) and EtOAc (50 mL). The

combined organic phases were washed with 10% aqu-

eous HCl (2Â25 mL) and saturated aqueous NaCl

(2Â50 mL), dried (Na₂SO₄) and concentrated to aord

0.060 g (68%) of A3 identical to that prepared with

solution-phase EDCI.

Scheme 5.

applicable to the discovery of antagonists of ligand

induced protein±protein dimerization/oligomerization

and their conversion to potential agonists. Such applica-

tions are in progress and will be disclosed in due course.

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(phenyl)ethyl)imino-

1

diacetic acid monoamide (3, A1): H NMR (DMSO-d₆,

Experimental

500 MHz) d 8.29 (m, 1H), 7.27 (m, 5H), 3.90, 3.86, 3.83

and 3.80 (four s, 4H), 3.33 (m, 2H), 2.73 (m, 2H), 1.35

and 1.33 (two s, 9H); IR (®lm) V_max3291, 2977, 2931,

1700, 1653, 1635, 1559, 1509, 1497, 1456, 1394, 1368, 1251,

N-((tert-Butyloxy)carbonyl)iminodiacetic acid (2). A 1 L

¯ask was charged with iminodiacetic acid (13.3 g,

100 mmol), dioxane (200 mL) and NaOH (8 g,

1358

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

Figure 7. Synthesis of a series of analogues for optimization of the A component of 5, AXB10C4 (A-scan).

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1359

Figure 8. Synthesis of a series of analogues for optimization of the B component of 5, A6BXC4 (B-scan).

1360

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1163, 1141, 857, 750, 700 cm ¹; FABHRMS (NBA±NaI)

N-((tert-Butyloxy)carbonyl)-N⁰-(2(4-¯uorophenyl)ethyl)-

iminodiacetic acid monoamide (3, A6): ¹H NMR

(DMSO-d₆, 500 MHz) d 8.23 (m, 1H), 7.24 (m, 2H), 7.09

(m, 2H), 3.89, 3.86, 3.82 and 3.80 (four s, 4H), 3.30 (m,

2H), 2.71 (m, 2H), 1.35 and 1.32 (two s, 9H); IR (®lm)

V_max3852, 3744, 3675, 3648, 3295, 2978, 1700, 1684,

1653, 1635, 1559, 1540, 1510, 1457, 1394, 1368, 1222,

1161, 896, 772 cm ¹; FABHRMS (NBA±NaI) m/z

355.1661 (M+H⁺, C₁₇H₂₃N₂O₅requires 355.1669).

m/z 337.1769 (M+H⁺, C₁₇H₂₄N₂O₅requires 337.1763).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-hydroxyphenyl)-

ethyl)iminodiacetic acid monoamide (3, A3): ¹H NMR

(DMSO-d₆, 500 MHz) d 9.19 (d, 1H, J=3.8 Hz), 8.26

(m, 1H), 6.99 (d, 2H, J=6.0 Hz), 6.66 (d, 2H,

J=6.0 Hz), 3.91, 3.87, 3.83 and 3.80 (four s, 4H), 3.22

(m, 2H), 2.60 (m, 2H), 1.35 and 1.33 (two s 9H); IR (®lm)

V_max3406, 1653, 1559, 1540, 1517, 1457, 1250, 1049,

1025, 1001, 826, 765 cm ¹; FABHRMS (NBA±NaI) m/z

353.1719 (M+H⁺, C₁₇H₂₄N₂O₆requires 353.1713).

N-((tert-Butyloxy)carbonyl)-N⁰-(5-((benzyloxycarbonyl)-

amino)-5-(methoxycarbonyl)pentyl)iminodiacetic acid mono-

1

amide (3, A7): H NMR (CDCl₃, 250 MHz) d 7.30 (m,

5H), 5.10 (m, 2H), 4.00 (m, 4H), 3.70 (m, 4H), 3.30 (m,

2H), 1.80 (m, 2H), 1.50 (m, 13H); IR (®lm) V_max3328,

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(3-methoxyphenyl)-

ethyl)iminodiacetic acid monoamide (3, A4): ¹H NMR

(DMSO-d₆, 500 MHz) d 8.26 (m, 1H), 7.19 (m, 1H), 6.76

(m, 3H), 3.90, 3.87, 3.84 and 3.81 (four s, 4H), 3.73 (s,

3H), 3.32 (m, 2H), 2.69 (q, 2H, J=10 Hz), 1.35 and 1.32

(two s, 9H); IR (®lm) V_max3853, 3744, 3675, 3648, 3294,

2976, 1700, 1653, 1635, 1584, 1559, 1506, 1490, 1457,

1

1394, 1368, 1259, 1165, 1038, 963, 877, 781, 697 cm

;

FABHRMS (NBA±NaI) m/z 367.1860 (M+H⁺,

C₁₈H₂₆N₂O₆requires 367.1869).

N-((tert-Butyloxy)carbonyl)-N⁰-(4-methoxybenzyl)imino-

1

diacetic acid monoamide (3, A5): H NMR (DMSO-d₆,

500 MHz) d 8.64 (m, 1H), 7.19 (m, 2H), 6.87 (m, 2H),

4.23 (d, 2H, J=5.8 Hz), 3.94, 3.92, 3.89 and 3.86 (four s,

4H), 3.72 (s, 3H), 1.35 and 1.29 (two s, 9H); IR (®lm)

V_max3406, 2978, 2530, 1700, 1653, 1559, 1514, 1457,

1394, 1368, 1302, 1250, 1165, 1142, 1048, 1026, 998, 908,

827, 766 cm ¹; FABHRMS (NBA±NaI) m/z 353.1720

(M+H⁺, C₁₇H₂₄N₂O₆requires 353.1713).

Scheme 6.

Figure 9.

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1361

2949, 1706, 1634, 1537, 1455, 1393, 1252, 1165,

1

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(2,5-dimethoxyphenyl)-

ethyl)-N⁰⁰-((5-(benzyloxycarbonyl)amino)-5-(methoxycarb-

onyl)pentyl)iminodiacetic acid diamide (4, A7B1): ¹H

NMR (CDCl₃, 500 MHz) d 7.27 (m, 5H), 6.74 (m, 3H),

5.70 (m, 1H), 5.08 (s, 2H), 4.35 (m, 1H), 3.71 (m,

13H), 3.50 (m, 2H), 3.25 (m, 2H), 2.75 (m, 2H), 1.80

(m, 2H), 1.55 (m, 2H), 1.38 (m, 11H); IR (®lm) V_max

3247, 3064, 2938, 1702, 1654, 1560, 1500, 1458, 1395,

1361, 1225, 1163, 1042, 847 cm ¹; FABHRMS (NBA±

CsI) m/z 805.2459 (M+Cs⁺, C₃₄H₄₈N₄O₁₀requires

805.2425).

1027 cm

; FABHRMS (NBA±CsI) m/z 642.1446

(M+Cs⁺, C₂₄H₃₅N₃O₉requires 642.1428).

N-((tert-Butyloxy)carbonyl)-N⁰-(4-(1⁰,4⁰-dioxolano)piper-

idino)iminodiacetic acid monoamide (3, A8): ¹H NMR

(CDCl₃, 400 MHz) d 4.21 (s, 2H), 3.97 (m, 4H), 3.88 (s,

2H), 3.75 (t, 2H, J=6 Hz), 3.50 (t, 2H, J=6 Hz), 1.74

(m, 4H), 1.42 and 1.418 (two s, 9H); IR (®lm) V_max

3462, 2973, 1702, 1609, 1452, 1396, 1241, 1140, 1103,

1

944, 908 cm

; FABHRMS (NBA) m/z 359.1830

(M+H⁺, C₁₆H₂₆N₂O₇requires 359.1818).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-¯uorophenyl)ethyl)-

N⁰⁰-(3-(N-pyrrolidin-2-onyl)propyl)iminodiacetic acid

diamide (4, A6B2): H NMR (DMSO-d₆, 500 MHz) d

General procedure for 4: N-((tert-butyloxy)carbonyl)-N⁰-

(4-methoxybenzyl)-N⁰⁰-(3-¯uoro-5-(tri¯uoromethyl)-

benzyl)iminodiacetic acid diamide (4, A5B5). The acid 3,

A5 (0.616 g, 1.75 mmol) was dissolved in DMF (18 mL)

and added to a ¯ask containing i-Pr₂NEt (0.45 g,

3.5 mmol) and 3-¯uoro-5-(tri¯uoromethyl)benzylamine

(B5, 0.37 g, 1.9 mmol). PyBOP (1.00 g, 1.9 mmol) was

added in portions and the resulting mixture was stirred

overnight (16 h). The reaction mixture was poured into

a separatory funnel containing 100 mL of 10% aqueous

HCl. Extraction into EtOAc (2Â40 mL) followed by

washing of the combined organic phases with 10%

aqueous HCl (2Â40 mL), saturated aqueous NaCl

(1Â40 mL), saturated aqueous NaHCO₃(2Â40 mL) and

saturated aqueous NaCl (1Â40 mL), drying (Na₂SO₄)

and evaporation provided 0.79 g (90%) of 4, A5B5 as an

1

8.65 (m, 2H), 7.25 (m, 2H), 7.09 (m, 2H), 3.79 (d, 2H,

J=6 Hz), 3.77 and 3.75 (two s, 2H), 3.30 (m, 4H),

3.17 (m, 2H), 3.08 (m, 2H), 2.77 (m, 2H), 2.19 (m,

2H), 1.96 (m, 2H), 1.58 (m, 2H), 1.33 and 1.31 (two s,

9H); IR (®lm) V_max3415, 3082, 2977, 2936, 1654,

1560, 1510, 1458, 1395, 1369, 1253, 1221, 1163, 1144,

1100, 1016, 961, 847, 761 cm ¹; FABHRMS (NBA±

CsI) m/z 611.1659 (M+Cs⁺, C₂₄H₃₅FN₄O₅requires

611.1646).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(phenyl)ethyl)-N⁰⁰-(1,2,

3,4-tetrahydro-1-(naphthyl)iminodiacetic acid diamide (4,

A1B2⁰): ¹H NMR (CDCl₃, 400 MHz) d 7.20 (m, 9H),

5.20 (m, 1H), 3.85 (m, 4H), 3.48 (m, 2H), 2.80 (m, 4H),

1.90 (m, 4H), 1.41 and 1.39 (two s, 9H); IR (®lm) V_max

1

oil: H NMR (DMSO-d₆, 400 MHz) d 9.50 (m, 0.5H),

9.30 (m, 0.5H), 8.96 (m, 1H), 7.49 (m, 3H), 7.18 (d, 2H,

J=6.4 Hz), 6.84 (d, 2H, J=8.8 Hz), 4.40 (m, 2H), 4.24

(m, 2H), 4.04 (s, 4H), 3.71 (s, 3H), 1.28 and 1.27 (two s,

9H); IR (®lm) V_max3246, 3071, 2978, 2935, 2839,

1656, 1610, 1563, 1514, 1456, 1394, 1366, 1343, 1302,

1251, 1230, 1170, 1131, 1030, 976, 959, 874, 847, 759,

718, 699 cm ¹; FABHRMS (NBA±NaI) m/z 550.1291

(M+Na⁺, C₂₅H₂₉F₄N₃O₅requires 550.1941).

3251, 2932, 1702, 1648, 1560, 1453, 1392, 1250,

1

1167 cm

; FABHRMS (NBA±NaI) m/z 488.2508

(M+Na⁺, C₂₇H₃₅N₃O₄requires 488.2525).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-methoxyphenyl)-

ethyl)-N⁰⁰-(2-(3,4-dimethoxyphenyl)ethyl)iminodiacetic

acid diamide (4, A2B3): ¹H NMR (DMSO-d₆, 400 MHz)

d 8.67 (m, 2H), 7.13 (m, 2H), 6.84 (m, 4H), 6.72 (d,

1H, J=8.0 Hz), 3.79 and 3.76 (two s, 2H), 3.73 (s,

3H), 3.72 and 3.70 (two s, 2H), 3.70 (s, 6H), 3.33 (m,

4H), 2.65 (m, 4H), 1.31 (s, 9H); IR (®lm) V_max3250,

3074, 2935, 2835, 2056, 1650, 1212, 1571, 1514, 1454,

1417, 1393, 1367, 1301, 1247, 1159, 1141, 1029, 960,

895, 848, 809, 762, 665 cm ¹; FABHRMS (NBA±CsI)

m/z 662.1850 (M+Cs⁺, C₂₈H₃₉N₃O₇requires

662.1842).

The remaining AXBX were characterized in a matrix

format which allowed for an assessment of the integrity

of each of the coupling reactions.

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(phenyl)ethyl)-N⁰⁰-(2-

(2,5-dimethoxyphenyl)ethyl)iminodiacetic acid diamide

1

(4, A1B1): H NMR (DMSO-d₆, 400 MHz) d 8.68 (m,

2H), 7.25 (m, 5H), 6.87 (d, 1H, J=8.5 Hz), 6.73 (s, 2H),

3.79 and 3.75 (two s, 2H), 3.72 (s, 3H), 3.72 and 3.68

(two s, 2H), 3.67 (s, 3H), 3.33 (m, 4H), 2.70 (m, 4H),

1.33 and 1.31 (two s, 9H); IR (®lm) V_max3423, 3074,

2975, 2934, 2833, 1970, 1651, 1567, 1500, 1454, 1393,

1367, 1337, 1305, 1250, 1225, 1165, 1141, 1043, 960,

895, 850, 802, 752, 701, 666 cm ¹; FABHRMS (NBA±

CsI) m/z 632.1745 (M+Cs⁺, C₂₇H₃₇N₃O₆requires

632.1737).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-hydroxyphenyl)-

ethyl)-N⁰⁰-(3,4,5-trimethoxybenzyl)iminodiacetic acid di-

amide (4, A3B4): ¹H NMR (DMSO-d₆, 400 MHz) d 9.20

(m, 1H), 8.70 (m, 1H), 7.01 (m, 2H), 6.68 (m, 2H), 6.65

(s, 1H), 6.62 (s, 1H), 4.30 (m, 2H), 3.85 (m, 4H), 3.78

and 3.76 (two s, 6H), 3.62 (s, 3H), 3.26 (m, 2H), 3.60 (m,

2H), 1.37 and 1.26 (two s, 9H); ¹H NMR (CDCl₃,

250 MHz) d 6.59 (d, 2H, J=8 Hz), 6.32 (d, 2H,

J=8 Hz), 6.20 (d, 2H, J=9 Hz),4.00 (m, 2H), 3.45 (m,

1362

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

13H), 3.00 (m, 2H), 2.21 (m, 2H), 0.98 and 0.92 (two s,

9H); IR (®lm) V_max3426, 2359, 1650, 1515, 1456, 1238,

1H), 8.67 (m, 1H), 6.98 (m, 2H), 6.67 (m, 2H), 4.15 and

4.10 (two s, 2H), 3.74 and 3.68 (two s, 2H), 3.44 (m,

8H), 3.26 (s, 3H), 2.24 (s, 3H), 3.22 (m, 2H), 2.57 (m,

2H), 1.34 and 1.33 (two s, 9H); IR (®lm) V_max3234,

1

1126 cm

; FABHRMS (NBA±CsI) m/z 664.1656

(M+Cs⁺, C₂₇H₃₇N₃O₈requires 664.1635).

3078, 2978, 2931, 1698, 1643, 1515, 1453, 1393, 1367,

1

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-¯uorophenyl)ethyl)-

N⁰⁰-(3,4,5-trimethoxybenzyl)iminodiacetic acid diamide

(4, A6B4): H NMR (DMSO-d₆, 400 MHz) d 9.15 (m,

1252, 1169, 1118, 1015, 962, 893, 832, 754, 665 cm

;

FABHRMS (NBA) m/z 468.4724 (M+H⁺, C₂₃H₃₇

N₃O₇requires 468.2710).

1

0.5H), 9.01 (m, 0.5H), 8.72 (m, 1H), 7.24 (m, 2H), 7.07

(m, 2H), 6.61 (d, 2H, J=11.4 Hz), 4.25 (m, 2H), 3.88 (s,

2H), 3.83 (m, 2H), 3.76 (s, 3H), 3.74 (s, 3H), 3.61 (s,

3H), 3.30 (m, 2H), 2.71 (m, 2H), 1.30 and 1.25 (two s,

9H); IR (®lm) V_max3348, 3073, 2997, 2839, 1700, 1653,

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(3-methoxyphenyl)ethyl)-

N⁰⁰-di(2-methoxyethyl)iminodiacetic acid diamide (4,

A4B6): ¹H NMR (CDCl₃, 400 MHz) d 7.15 (m, 1H),

6.75 (m, 3H), 4.16 (s, 1H), 4.04 (s, 1H), 3.91 (s, 1H), 3.55

(s, 1H), 3.54 (s, 4H), 3.50 (m, 10H), 3.30 (m, 5H), 2.80

1593, 1559, 1509, 1457, 1424, 1394, 1367, 1329, 1237,

1

1162, 1128, 1005, 959, 898, 826, 755, 667 cm

;

(m, 2H), 1.39 (s, 9H); IR (®lm) V_max3490, 3241, 2932,

1

FABHRMS (NBA±CsI) m/z 666.1574 (M+Cs⁺,

C₂₇H₃₆FN₃O₇requires 666.1592).

1703, 1643, 1583, 1454, 1254, 1167, 1118 cm

;

FABHRMS (NBA±CsI) m/z 614.1860 (M+Cs⁺,

C₂₄H₃₉N₃O₇requires 614.1842).

N-((tert-Butyloxy)carbonyl)-N⁰-(5-((benzyloxycarbonyl)-

amino)-5-methoxylcarbonyl)pentyl)-N⁰⁰-(3,4,5-trimethoxy-

benzyl)iminodiacetic acid diamide (4, A7B4): ¹H NMR

(CDCl₃, 500 MHz) d 8.59 and 8.20 (two s, 1H, NH),

7.25 (m, 5H), 6.60 and 6.52 (two s, 2H), 5.54 (apparent

d, 1H), 5.08 (apparent d, 2H), 4.38 (m, 3H), 3.88 (m,

13H), 3.32 (s, 3H), 3.25 (m, 2H), 1.80 (m, 2H), 1.74 (m,

2H), 1.68 (m, 2H), 1.38 and 1.29 (two s, 9H); IR (®lm)

V_max3426, 2995, 1641, 1508 cm ¹; FABHRMS (NBA±

CsI) m/z 821.2398 (M+Cs⁺, C₃₄H₄₈N₄O₁₁requires

821.2374).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-¯uorophenyl)ethyl)-

N⁰⁰-di(2-methoxyethyl)iminodiacetic acid diamide (4,

A6B6): ¹H NMR (CDCl₃, 500 MHz) d 9.20 and 9.96

(two t, 1H, NH), 7.05 (m, 2H), 6.80 (m, 2H), 4.05, 3.92,

3.76, and 3.66 (four s, 4H), 3.38 (m, 8H), 3.17 (m, 6H),

2.68 (m, 2H), 1.27 (s, 9H); IR (®lm) V_max3508, 3241,

3077, 2974, 2923, 1702, 1641, 1564, 1508, 1441, 1390,

1

1364 1251, 1221, 1164, 1010, 964, 928, 892, 826 cm

;

FABHRMS (NBA±CsI) m/z 602.1634 (M+Cs⁺,

C₂₃H₃₆FN₃O₆requires 602.1642).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-¯uorophenyl)ethyl)-

N⁰⁰-(3-¯uoro-5-(tri¯uoromethyl)benzyl)iminodiacetic acid

diamide (4, A6B5): H NMR (CDCl₃, 500 MHz) d 7.40

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-¯uorophenyl)ethyl)-

N⁰⁰-(5-hydroxy-3-oxapentyl)iminodiacetic acid diamide

(4, A6B7): H NMR (DMSO-d₆, 400 MHz) d 8.64 (m,

1

(d, 1H), 7.10 (m, 4H), 6.94 (m, 2H), 4.48 (m, 2H), 3.82

(m, 4H), 3.46 (m, 2H), 2.77 (m, 2H), 1.36 and 1.32 (two

s, 9H); IR (®lm) V_max3248, 3072, 2978, 2931, 1649,

2H), 7.26 (m, 2H), 7.08 (m, 2H), 3.79 (m, 4H), 3.37 (m,

10H), 2.71 (m, 2H), 1.33 and 1.30 (two s, 9H); IR (®lm)

V_max3450, 2977, 2937, 2118, 1650, 1459, 1609, 1456,

1561, 1508, 1455, 1390, 1343, 1249, 1226, 1167, 1132,

1

1392, 1368, 1340, 1253, 1220, 1161, 1140, 1065, 960,

1

1020, 972, 955, 867, 826, 773, 714, 697, 550 cm

;

823 cm

;

FABHRMS (NBA±CsI) m/z 574.1317

FABHRMS (NBA±NaI) m/z 530.2063 (M+H⁺,

C₂₅H₂₈F₅N₃O₄requires 530.2078).

(M+Cs⁺, C₂₁H₃₂FN₃O₆requires 574.1329).

N-((tert-Butyloxy)carbonyl)-N⁰-(4-methoxybenzyl)-N⁰⁰-

(trans-2-phenylcyclopropyl)iminodiacetic acid diamide (4,

A5B7⁰): ¹H NMR (CDCl₃, 400 MHz) d 7.20 (m, 7H),

6.79 (m, 2H), 4.35 (m, 2H), 3.75 (m, 7H), 2.95 (m, 1H),

2.06 (m, 1H), 1.39 and 1.30 (two s, 9H), 1.20 (m, 2H);

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-methoxyphenyl)-

ethyl)-N⁰⁰-di(2-methoxyethyl)iminodiacetic acid diamide

(4, A2B6): H NMR (DMSO-d₆, 500 MHz) d 8.70 (m,

1H), 7.12 (m, 2H), 6.82 (m, 2H), 4.15 (s, 1H), 4.10 (s,

1H), 3.74 (s, 1H), 3.71 (s, 3H), 3.68 (s, 1H), 3.43 (m,

10H), 3.26 (s, 3H), 3.23 (s, 3H), 2.64 (m, 2H), 1.34 and

1.32 (two s, 9H); IR (®lm) V_max3852, 3749, 3674, 3647,

1

IR (®lm) V_max3414, 2068, 1650, 1513, 1455, 1393, 1249,

1

1166 cm

; FABHRMS (NBA±CsI) m/z 600.1490

(M+Cs⁺, C₂₆H₃₃N₃O₅requires 600.1475).

3446, 2932, 1700, 1684, 1653, 1635, 1559, 1540, 1513,

1

1457, 1394, 1367, 1247, 1176, 1116, 1033, 844 cm

;

N-((tert-Butyloxy)carbonyl)-N⁰-(4-methoxybenzyl)-N⁰⁰-(2-

(4-methoxyphenyl)ethyl)iminodiacetic acid diamide (4,

A2B7⁰⁰): ¹H NMR (CDCl₃, 500 MHz) d 7.20±7.00 (m,

4H), 6.79 (m, 4H), 4.36 (m, 2H), 3.74 (m, 10H), 3.40 (m,

2H), 2.75 (m, 2H), 1.36 and 1.32 (two s, 9H); IR (®lm)

FABHRMS (NBA±CsI) m/z 614.1820 (M+Cs⁺,

C₂₄H₃₉N₃O₇requires 614.1842).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-hydroxyphenyl)ethyl)-

N⁰⁰-di(2-methoxyethyl)iminoacetic acid diamide (4,

A3B6): ¹H NMR (DMSO-d₆, 400 MHz) d 9.11 (br s,

V_max3225, 3072, 2931, 2837, 1696, 1655, 1567, 1514,

1

1455, 1390, 1243, 1173, 1138, 1032, 820 cm

;

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1363

FABHRMS (NBA±NaI) m/z 486.2615 (M+H⁺, C₂₆H₃₅

N₃O₆requires 486.2604).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-methoxyphenyl)ethyl)-

N⁰⁰-((5-(benzyloxycarbonyl)amino)-5-(methoxycarbonyl)-

pentyl)iminodiacetic acid diamide (4, A7B12 and

A2B10): ¹H NMR (CDCl₃, 500 MHz) d 7.31 (m, 5H),

7.10 (m, 2H), 6.80 (m, 2H), 5.60 (m, 1H), 5.07 (s, 2H),

4.30 (m, 1H), 3.75 (m, 10H), 3.50 (m, 2H), 3.25 (m, 2H),

2.75 (m, 2H), 1.75 (m, 2H), 1.38 (m, 13H); IR (®lm)

V_max3248, 3072, 2943, 1713, 1661, 1514, 1455, 1390,

1367, 1249, 1214, 1173, 1138, 1038, 903, 844, 732, 697,

597, 562 cm ¹; FABHRMS (NBA±CsI) m/z 775.2290

(M+Cs⁺, C₃₃H₄₆N₄O₉requires 775.2319).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-methoxyphenyl)ethyl)-

N⁰⁰-(3-(2,6-dimethoxybenzoyl)aminopropyl)iminodiacetic

acid diamide (4, A2B8): ¹H NMR (DMSO-d₆, 500 MHz)

d 8.66 (m, 2H), 8.00 (m, 1H), 7.27 (m, 1H), 7.12 (m, 2H),

6.83 (m, 2H), 6.64 (d, 2H, J=10 Hz), 3.80 (m, 4H), 3.71

(s, 9H), 3.22 (m, 6H), 2.64 (m, 2H), 1.60 (m, 2H), 1.34

and 1.31 (two s, 9H); IR (®lm) V_max3260, 2936, 2838,

1651, 1598, 1514, 1474, 1393, 1388, 1302, 1252, 1158,

1

1141, 1113, 1034, 959, 897, 847, 757, 666 cm

;

FABHRMS (NBA±CsI) m/z 719.2079 (M+Cs⁺,

C₃₀H₄₂N₄O₈requires 719.2057).

N-((tert-Butyloxy)carbonyl)-N⁰-((3-methoxyphenyl)ethyl)-

N⁰⁰-(5-(benzyloxycarbonyl)amino)-5-(methoxycarbonyl)-

pentyl)iminodiacetic acid diamide (4, A7B2⁰⁰and

A4B10): ¹H NMR (DMSO-d₆, 500 MHz) d 8.68 (m,

3H), 7.73 (m, 1H), 7.34 (m, 5H), 7.17 (m, 1H), 7.76 (m,

2H), 5.03 (s, 2H), 3.99 (m, 2H), 3.76 (m, 7H), 3.61 (s,

3H), 3.30 (m, 2H), 3.05 (m, 2H), 2.68 (m, 2H), 1.36 (m,

14H); IR (®lm) V_max3384, 3268, 3074, 2936, 1707, 1656,

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-¯uorophenyl)ethyl)-

N⁰⁰-(2-(2⁰-thienyl)ethyl)iminodiacetic acid diamide (4,

A6B8⁰): ¹H NMR (CDCl₃, 400 MHz) d 7.15 (m, 3H),

6.91 (m, 3H), 6.81 (m, 1H), 3.74 (d, 4H), 3.42 (m, 4H),

3.00 (m, 2H), 2.70 (m, 2H), 1.34 (s, 9H); IR (®lm) V_max

3238, 2974, 1655, 1570, 1509, 1454, 1394, 1165,

1

1583, 1562, 1546, 1492, 1454, 1393, 1367, 1266, 1210,

1

849 cm

;

FABHRMS (NBA±CsI) m/z 596.0975

1166, 1039, 848, 780, 752, 697 cm

;

FABHRMS

(M+Cs⁺, C₂₃H₃₀N₃O₄FS requires 596.0995).

(NBA±CsI) m/z 775.2328 (M+Cs⁺, C₃₃H₄₆N₄O₉

requires 775.2319).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(phenyl)ethyl)-N⁰⁰-(5-

acetamido-5-(methoxycarbonyl)pentyl)iminodiacetic acid

diamide (4, A1B9): ¹H NMR (DMSO-d₆, 500 MHz) d

8.73 (m, 2H), 8.57 (m, 1H), 7.27 (m, 5H), 4.17 (m, 1H),

3.78 (m, 4H), 3.60 (s, 3H), 3.32 (m, 2H), 3.12 (m, 2H),

2.71 (m, 2H), 1.43 (m, 4H), 1.39 (m, 2H), 1.32 and 1.30

(two s, 9H); IR (®lm) V_max3751, 3277, 3079, 2937, 1738,

1652, 1557, 1514, 1456, 1394, 1369, 1301, 1248, 1177,

1143, 1033, 961, 894, 847, 767, 665 cm ¹; FABHRMS

(NBA±CsI) m/z 653.1983 (M+Cs⁺, C₂₆H₄₀N₄O₇

requires 653.1951).

N-((tert-Butyloxy)carbonyl)-N⁰-(4-(1⁰,4⁰-dioxolano)piper-

idino)-N⁰⁰-((5-(benzyloxycarbonyl)amino)-5-(methoxycarb-

onyl)pentyl)iminodiacetic acid diamide (4, A7B14 and

A8B10): ¹H NMR (CDCl₃, 400 MHz) d 7.33 (m, 5H),

5.10 (s, 2H), 4.30 (m, 1H), 4.00 (m, 6H), 3.75 (m, 7H),

3.43 (m, 2H), 3.20 (m, 3H), 1.80 (m, 2H), 1.68 (m, 5H),

1.55 (m, 3H), 1.50 (m, 9H); IR (®lm) V_max3425, 2955,

1

1698, 1643, 1537, 1453, 1394, 1253, 1167, 1102 cm

;

FABHRMS (NBA±CsI) m/z 767.2293 (M+Cs⁺,

C₃₁H₄₇N₄O₁₀requires 767.2268).

N-((tert-Butyloxy)carbonyl)-N⁰-(5-((benzyloxycarbonyl)-

amino)-5-(methoxycarbonyl)pentyl)-N⁰⁰-methyl-N⁰⁰-(2-(3,4-

dimethoxyphenyl)ethyl)iminodiacetic acid diamide (4,

A7B9⁰): ¹H NMR (CDCl₃, 400 MHz) d 7.30 (m, 5H),

6.70 (m, 3H), 5.07 (d, 2H), 4.30 (m, 1H), 3.85 (m, 8H),

3.70 and 3.68 (two s, 3H), 3.55 (m, 4H), 3.13 (m, 2H),

2.90 (m, 2H), 2.70 (s, 3H), 1.55 (m, 6H), 1.39 and 1.36

(two s, 9H); IR (®lm) V_max3248, 2936, 1704, 1642, 1516,

1454, 1392, 1263, 1160 cm ¹; FABHRMS (NBA±CsI) m/z

819.2606 (M+Cs⁺, C₃₅H₅₀N₄O₁₀requires 819.2581).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-methoxyphenyl)-

ethyl)-N⁰⁰-(2-(phenyl)ethyl)iminodiacetic acid diamide (4,

A2B11): ¹H NMR (CDCl₃, 500 MHz) d 7.16 (m, 9H),

3.71 (m, 7H), 3.45 (m, 2H), 3.30 (m, 2H), 2.90±2.60 (m,

4H), 1.36 (s, 9H); IR (®lm) V_max3237, 3072, 2931, 1567,

1555, 1508, 1455, 1390, 1296, 1243, 1173, 1138, 1032,

1

820 cm

;

FABHRMS (NBA±NaI) m/z 470.2642

(M+H⁺, C₂₆H₃₅N₃O₅requires 470.2655).

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-¯uorophenyl)ethyl)-

N⁰⁰-((5-(benzyloxycarbonyl)amino)-5-(methoxycarbonyl)-

N-((tert-Butyloxy)carbonyl)-N⁰-benzyl-N⁰⁰-((5-benzyloxy-

carbonylamino)-5-(methoxycarbonyl)pentyl)iminodiacetic

pentyl)iminodiacetic acid diamide (4, A7B13): H NMR

1

(CDCl₃, 500 MHz) d 7.31 (m, 5H), 7.10 (m, 2H), 6.92

(m, 2H), 5.60 (m, 1H), 5.05 (s, 2H), 4.35 (m, 1H), 3.75

(m, 7H), 3.50 (m, 2H), 3.25 (m, 2H), 2.75 (m, 2H), 1.80

(m, 2H), 1.55 (m, 2H), 1.38 (m, 11H); IR (®lm) V_max

3260, 3060, 2931, 2861, 1708, 1655, 1549, 1508, 1455,

acid diamide (4, A7B9⁰⁰): H NMR (CDCl₃, 500 MHz) d

1

7.28 (m, 10H), 5.60 (m, 1H), 5.10 (s, 2H), 4.35 (m, 3H),

3.80 (m, 4H), 3.69 (s, 3H), 3.25 (m, 2H), 1.80 (m, 2H),

1.38 (m, 13H); IR (®lm) V_max3260, 3072, 2943, 1690,

1

1549, 1455, 1390, 1367, 1249, 1161, 844, 732, 697 cm

;

1390, 1367, 1249, 1220, 1161, 1138, 1044, 891, 832, 738,

1

FABHRMS (NBA±NaI) m/z 621.2914 (M+Na⁺,

C₃₁H₄₂N₄O₈requires 621.2900).

697 cm

;

FABHRMS (NBA±CsI) m/z763.2102

(M+Cs⁺, C₃₂H₄₃FN₄O₈requires 763.2119).

1364

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

N-((tert-Butyloxy)carbonyl)-N⁰-(2-(4-¯uorophenyl)ethyl)-

N⁰⁰-(furan-2-ylmethyl)iminodiacetic acid diamide (4,

A6B15): ¹H NMR (CDCl₃, 500 MHz) d 8.59±8.34 (m,

NH, 2H), 7.21 (m, 1H), 7.07 (m, 2H), 6.85 (m, 2H), 6.17

(m, 2H), 4.33 (m, 2H), 3.74 (m, 4H), 3.37 (m, 2H), 2.72

(m, 2H), 1.29 and 1.25 (two s, 9H); IR (®lm) V_max3237,

3060, 2966, 2919, 1655, 1555, 1502, 1455, 1390, 1361,

1249, 1220, 1161, 1138, 1014, 961, 897, 826, 732, 662,

597, 556 cm ¹; FABHRMS (NBA±NaI) m/z 434.0208

(M+H⁺, C₂₂H₂₈FN₃O₅requires 434.2091).

aqueous NaHCO₃(50 mL) and saturated aqueous NaCl

(50 mL), dried (Na₂SO₄) and the solvent was removed

under reduced pressure to provide 73 mg (89%) of the title

substance as an oil, which crystallized from slowly evapor-

ating EtOAc: ¹H NMR (DMSO-d₆, 250 MHz) d 8.62 and

8.23 (two t, 2H, NH), 7.11±7.06 (m, 5H), 7.00 (s, 2H, vinyl),

6.84±6.81 (m, 4H), 4.55, 4.27, 4.04 and 3.86 (br s, or pairs of

s, total 8H, NCH₂CO), 3.70 (two s, 6H, OCH₃), 2.61 (m,

4H, ArCH₂); IR (®lm) V_max3467, 3262, 1644, 1246,

1

1115 cm

;

FABHRMS (NBA±CsI) m/z 843.4542

(M+H⁺, C₄₂H₆₂N₆O₁₂requires 843.4504).

General procedure for 5: sublibrary A1B3C1±C10. A

sample of 4, A1B3 (0.075 g, 0.15 mmol) in CHCl₃(1 mL)

was treated with 4 N HCl±dioxane (1 mL) in a 4 mL vial

and this mixture was allowed to stand for 2 h. TLC

(10% CH₃OH±CHCl₃eluent) then indicated that con-

version to the amine was complete. The solvent and

excess acid were removed by evaporation. A stock solu-

tion was prepared by diluting a mixture of 0.5 mmol of

each diacid C1±C10 and 45 mmol of i-Pr₂NEt to 100 mL

in anhydrous DMF. This stock solution (1mL,

0.005 mmol of each diacid, 0.45 mmol of i-Pr₂NEt) was

added to the diamide and the mixture was shaken to eect

dissolution. PyBrOP (0.070g, 0.15 mmol) was added and

the mixture was capped, shaken, and allowed to stand for

8 h. The reaction mixture was diluted with EtOAc (25 mL)

and washed with 20% aqueous HCl saturated with NaCl

(3Â25 mL), saturated aqueous NaHCO₃(1Â25 mL) and

saturated aqueous NaCl (1Â25 mL), dried (Na₂SO₄) and

concentrated to aord 0.036g (79%) of the sublibrary.

N,N⁰-Bis(N-(2-(4-methoxyphenyl)ethyl)carboxamido-

methyl)-N,N⁰-bis(N,N-di(2-methoxyethyl)carboxamido-

1

methyl)ethyne-1,2-dicarboxamide (5, A2B6C1): H NMR

(DMSO-d₆, 250 MHz) d 8.43 and 8.23 (br t, 2H),

7.13±7.08 (m, 4H), 6.85±6.81 (m, 4H), 4.54, 4.26, 4.08

and 3.86 (br s or pairs of s, total 8H), 3.70 (two s, 6H),

2.62 (m, 4H); IR (®lm) V_max3487, 3272, 1651, 1246,

1

1115 cm

; FABHRMS (NBA±CsI) m/z 973.3369

(M+Cs⁺, C₄₂H₆₀N₆O₁₂requires 973.3324).

(E)-N,N⁰-Bis(N-(2-(4-methoxyphenyl)ethyl)carboxamido-

methyl)-N,N⁰-bis(N,N-di(2-methoxyethyl)carboxamido-

methyl)-2-butene-1,4-dicarboxamide (5, A2B6C3): ¹H

NMR (DMSO-d₆, 250 MHz) d 8.69 and 8.25 (two t,

2H), 7.12±7.08 (m, 4H), 6.84±6.80 (m, 4H), 5.50 (m,

2H), 4.40, 4.16, 3.93 and 3.78 (br s, 8H), 3.69 (two s,

6H), 2.63 (m, 4H); IR (®lm) V_max3446, 3261, 1650,

1

1245, 1115 cm

;

FABHRMS (NBA±CsI) m/z

1003.3841 (M+Cs⁺, C₄₄H₆₆N₆O₁₂requires 1003.3793).

MS data con®rming the integrity of the mixtures with

the inclusion of each expected member was collected for

the following 5 mixtures: A1B1C1±10, A2B1C1±10,

A3B1C1±10, A2B2C1±10, A2B6C1±10, A3B3C1±10,

A4B4C1±10, A5B5C1±10, A6B6C1±10, A5B7C1±10,

A4B8C1±10, A3B9C1±10 and A2B10C1±10.

N,N⁰-Bis(N-(2-(4-methoxyphenyl)ethyl)carboxamido-

methyl)-N,N⁰-bis(N,N-di(2-methoxyethyl)carboxamido-

methyl)benzene-1,3-dicarboxamide (5, A2B6C4): ¹H

NMR (DMSO-d₆, 250 MHz) d 8.45, 8.41 and 8.29 (t, t and

m, 2H), 7.45±7.33 (m, 4H), 7.15±7.09 (m, 4H), 6.84±6.81

(m, 4H), 4.31, 4.22, 3.94 and 3.77 (br s, 8H), 3.70 (s, 6H),

General procedure for the synthesis of individual sub-

library entries for 5, (A2B6C1±10): preparation of (E)-

(N,N⁰-bis(N-(2-(4-methoxyphenyl)ethyl)carboxamido-

methyl)-N,N⁰-bis(N,N-di(2-methoxyethyl)carboxamido-

methyl)ethene-1,2-dicarboxamide (5, A2B6C2). The

BOC-derivative 4, A2B6 (0.84 g) was stirred in 4 N HCl±

dioxane (8.5 mL) for 2 h. Removal of the solvent under

a stream of N₂and in vacuo gave the deprotected mate-

rial (0.78 g), which was dissolved in anhydrous DMF to

provide a 0.15 M solution (12.5 mL). An aliquot of this

solution (2 mL, 0.3 mmol) was syringed into a two dram

vial equipped with a stirring bar containing 11.6 mg

(0.1 mmol) of fumaric acid. i-Pr₂NEt (150 mL, 0.9 mmol)

and PyBrOP (140mg, 0.3 mmol) were added and the

reaction mixture was stirred for 16 h at 25 ^ꢀC. The reac-

tion mixture was diluted with EtOAc (50mL) and

washed (3Â50 mL) with acidic saturated aqueous NaCl

(10% aqueous HCl/saturated aqueous NaCl 1/1), 5%

2.65 (m, 4H); IR (®lm) V_max3487, 3262, 1651, 1246,

1

1113 cm

; FABHRMS (NBA±CsI) m/z 1025.3678

(M+Cs⁺, C₄₆H₆₄N₆O₁₂requires 1025.3637).

N,N⁰-Bis(N-(2-(4-methoxyphenyl)ethyl)carboxamido-

methyl)-N,N⁰-bis(N,N-di(2-methoxyethyl)carboxamido-

methyl)benzene-1,4-dicarboxamide (5, A2B6C5): ¹H

NMR (DMSO-d₆, 250 MHz) d 8.40 and 8.28 (two m,

2H), 7.38±7.34 (m, 4H), 7.14±7.08 (m, 4H), 6.85±6.81 (m,

4H), 4.31, 4.23, 3.93 and 3.77 (br s or d, 8H), 3.70 (br s,

6H), 2.65 (m, 4H); IR (®lm) V_max3497, 3272, 1644, 1244,

1

1115 cm

; FABHRMS (NBA±CsI) m/z 1025.3677

(M+Cs⁺, C₄₆H₆₄N₆O₁₂requires 1025.3637).

N,N⁰-Bis(N-(2-(4-methoxyphenyl)ethyl)carboxamido-

methyl)-N,N⁰-bis(N,N-di(2-methoxyethyl)carboxamido-

methyl)napthalene-1,4-dicarboxamide (5, A2B6C6): ¹H

NMR (DMSO-d₆, 250 MHz) d 8.31, 8.20 and 8.09 (m,

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1365

4H), 7.70±7.59 (m, 2H), 7.38±7.28 (m, 2H), 7.18±7.16

(m, 2H), 7.02±6.95 (m, 2H), 6.87±6.78 (m, 4H), 4.85,

4.40, 4.15, and 4.02 (br s, 4H), 3.70 (m, 6H), 2.69 (m,

diluted with EtOAc (90 mL) and washed with 10% aqu-

eous HCl (3Â90 mL), saturated aqueous NaHCO₃

(2Â90 mL) and saturated aqueous NaCl (90 mL), dried

(Na₂SO₄) and concentrated to aord 0.0441 g (81%) of

the sublibrary.

1

4H); IR (®lm) V_max3282, 1650, 1241, 1113 cm

;

FABHRMS (NBA±CsI) m/z 1075.3835 (M+Cs⁺,

C₅₀H₆₆N₆O₁₂requires 1075.3793).

ESMS data con®rming the integrity of the mixtures with

the inclusion of each expected member was collected for

the following 15 mixtures: A1B1C31±37, A1B2⁰C31±37,

A1B3C31±37, A1B9⁰C31±37, A2B3C31±37, A2B8⁰C31±

37, A3B2⁰C31±37, A3B4C31±37, A4B6C31±37, A5B7⁰

C31±37, A5B10C31±37, A6B8⁰C31±37, A7B9⁰C31±37,

A8B10C31±37. The seven components 15: A1B3C31±

A1B3C37 were individually prepared following the pro-

cedure detailed above and combined to provide an

authentic equimolar mixture. The individual coupling

yields were comparable with that of the mixture synth-

esis (Table 6) and the mass spectrum of the mixture

synthesis and authentic mixture material were indis-

tinguishable and the HPLC revealed no distinguishable

features between the two mixtures (Fig. 10).

cis- and trans-N,N⁰-Bis(N-(2-(4-methoxyphenyl)ethyl)-

carboxamidomethyl)-N,N⁰-bis(N,N-di(2-methoxyethyl)-

carboxamidomethyl)cyclohexane-1,3-dicarboxamide (5,

A2B6C7,8): (mixture of cis- and trans-isomers) ¹H

NMR (DMSO-d₆, 250 MHz) d 8.78, 8.67, 8.51 and 8.19

(m, 2H), 7.17±7.10 (m, 4H), 6.86±6.83 (m, 4H), 4.50±

3.75 (several m, 8H), 3.72 (br s, 6H), 2.64 (m, 4H); IR

1

(®lm) V_max3487, 3262, 1642, 1246, 1113 cm

;

FABHRMS (NBA±CsI) m/z 1031.4147 (M+Cs⁺,

C₄₆H₇₀N₆O₁₂requires 1031.4106).

cis- and trans-N,N⁰-Bis(N-(2-(4-methoxyphenyl)ethyl)-

carboxamidomethyl)-N,N⁰-bis(N,N-di(2-methoxyethyl)-

carboxamidomethyl)cyclohexane-1,4-dicarboxamide (5,

A2B6C9,10): (mixture of cis- and trans-isomers) ¹H

NMR (DMSO-d₆, 250 MHz) d 8.67, 8.23 and 8.17 (m,

2H), 7.13±7.08 (m, 4H), 6.85±6.80 (m, 4H), 4.50±3.75

(several m, 8H), 3.70 (br s, 6H), 2.62 (m, 4H); IR (®lm)

V_max3477, 3262, 1644, 1246, 1115 cm ¹; FABHRMS

(NBA±CsI) m/z 1031.4148 (M+Cs⁺, C₄₆H₇₀N₆O₁₂

requires 1031.4106).

1

15, A1B3C31: H NMR (CDCl₃, 400 MHz) d 7.17 (m,

18H), 6.72 (m, 9H), 3.80 (m, 30H), 3.40 (m, 12H), 2.75

(m, 12H); IR (®lm) V_max3260, 3063, 2933, 1650, 1515,

1454, 1261, 1236, 1156, 1141, 1027 cm ¹; ESMS pos:

M+H⁺1355, M+Na⁺1377; neg: M H⁺1353,

M+Cl 1389.

1

Preparation of the 5, sublibrary A2B6C1±10. A stock

solution was prepared through diluting a mixture of

0.5 mmol of each diacid C1±10 and 45 mmol of i-Pr₂NEt

to 100 mL in anhydrous DMF. A 2 mL sample of this

stock solution (0.1 mmol of diacid) was added to 2 mL

15, A1B3C32: H NMR (CDCl₃, 400 MHz) d 7.52 (m,

15H), 7.10 (m, 9H), 4.10 (m, 30H), 3.75 (m, 12H), 3.10

(m, 12H); IR (®lm) V_max3262, 2926, 2359, 1658, 1515,

1454, 1261, 1236, 1141, 1027 cm ¹; ESMS pos: M+H⁺

1361, M+Na⁺1383; neg: M H⁺1359, M+Cl 1395.

.

of the solution containing A2B6 HCl (0.3 mmol). After

1

the addition of PyBrOP (140 mg, 0.3 mmol), the mixture

was stirred for 16 h. Work-up as described above pro-

vided 84.5 mg (95%) of the mixture as an o-white

solid. TLC (10% CH₃OH±CHCl₃) R_f=0.47±0.62. The

results from HPLC-MS analysis of this mixture

(including selective ion monitoring) were in good agree-

ment with those obtained using a mixture produced by

pooling the individual compounds.

15, A1B3C33: H NMR (CDCl₃, 400 MHz) d 7.20 (m,

18H), 6.72 (m, 9H), 3.80 (m, 36H), 3.45 (m, 12H), 2.80

(m, 12H); IR (®lm) V_max3279, 2932, 1658, 1515, 1261,

1158, 1027 cm ¹; ESMS pos: M+H⁺1445, M+Na⁺

1467; neg: M-H⁺1443, M+Cl 1478.

1

15, A1B3C34: H NMR (CDCl₃, 400 MHz) d 7.40 (m,

3H), 7.25 (m, 15H), 6.75 (m, 9H), 4±4.40 (m, 6H), 3.85

(m, 30H), 3.50 (m, 12H), 2.80 (m, 12H); IR (®lm) V_max

3278, 2932, 1658, 1515, 1453, 1261, 1235, 1119,

1027 cm ¹; ESMS pos: M+H⁺1560, M+Na⁺1582;

neg: M H⁺1557, M+Cl 1594.

General procedure for 15: sublibrary A1B3C31±37. A

sample of 4, A1B3 (0.083 g, 0.157 mmol) in CHCl₃(1 mL)

was treated with 4 N HCl±dioxane (1 mL) in a 4 mL vial

and this mixture was allowed to stand for 3 h. The sol-

vent and excess acid were removed by evaporation. The

resulting residue is dissolved in 1 mL of DMF and

0.25 mL (1.5 mmol, 10 equiv) of i-Pr₂NEt was added.

After dissolution, 0.1 mL (0.035 mmol) of a triacid stock

solution (prepared by diluting a mixture of 0.45 mmol of

each triacid C31±C37³⁷in 9 mL of a mixture DMF/

CHCl₃8:1) was added, followed by 74 mg (0.157 mmol) of

PyBrOP. After stirring for 16 h, the reaction mixture was

Table 6. Individual and mixture coupling yields, 15

A1B3C31

A1B3C32

A1B3C33

A1B3C34

100%

47%

89%

73%

A1B3C35

A1B3C36

A1B3C37

average

94%

88%

85%

82%

A1B3C31±C37 81%

1366

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1.66 mmol), i-Pr₂NEt (2.60 mL, 14.98 mmol) and

PyBrOP (2.32 g, 5.00 mmol) were added sequentially.

The reaction mixture was stirred for 16 h at 25 ^ꢀC before

being diluted with EtOAc (200 mL) and washed with

10% aqueous HCl (2Â100 mL), saturated aqueous

NaHCO₃(2Â100 mL), saturated aqueous NaCl

(100 mL) and dried (Na₂SO₄). The solvent was removed

under reduced pressure to provide 2.09 g (94%) of the

1

title substance as an oil: H NMR (CDCl₃, 500 MHz) d

7.38 (br s, 10H), 6.75 (br s, 6H), 5.80±5.50 (m, 2H), 5.06

(s, 4H), 4.35 (br s, 2H), 4.21±3.62 (m, 28H), 3.50 (s, 4H),

3.20 (br s, 4H), 2.72 (br s, 4H), 1.72 (m, 4H), 1.60 (m,

4H), 1.35 (br s, 13H); IR (®lm) V_max3292, 3066, 2938,

2868, 1655, 1516, 1455, 1262, 1157, 1027, 846, 735,

1

699 cm

; FABHRMS (NBA±CsI) m/z 1474.5527

(M+Cs⁺, C₆₇H₉₁N₉O₂₀requires 1474.5435).

Figure 10. Reconstituted equimolar (left) and combinatorial

synthesis (right) mixture of 15, A1B3C31±37. Reverse-phase

HPLC separation of the mixture: 3.9Â300 mm C18, 1 mL/min,

CH₃CN±H₂O (containing 0.035% TFA) 50±50% to 65±35%

(30 min linear gradient), with monitored detection at 254 nm.

All desired components of the mixture elute within the reten-

tion times of 9±20 min.

N,N⁰-Bis(N-(2-(4-¯uorophenyl)ethyl)carboxamidomethyl)-

N,N⁰-bis(N,N-di(2-methoxyethyl)carboxamidomethyl)-

N⁰⁰-((tert-butyloxy)carbonyl)iminodiacetic acid diamide

(16, A6B6): ¹H NMR (CDCl₃, 500 MHz) d 7.13 (m,

4H), 6.89 (m, 4H), 4.51±3.82 (m, 12H), 3.45±3.21 (m,

32H), 2.73 (m, 4H), 1.34 (br s, 9H); IR (®lm) V_max3261,

1

15, A1B3C35: H NMR (CDCl₃, 400 MHz) d 7.20 (m,

2930, 1659, 1509, 1450, 1365, 1217, 1118, 965, 844 cm

;

27H), 6.78 (m, 9H), 4.50 (m, 6H), 3.80 (m, 30H), 3.50

(m, 12H), 3.25 (m, 3H), 2.80 (m, 12H), 2.40 (m, 3H); IR

(®lm) V_max3273, 2934, 1650, 1515, 1453, 1261, 1082,

1027 cm ¹; ESMS pos: M+H⁺1680, M+Na⁺1702;

neg: M H⁺1677.

FABHRMS (NBA±CsI) m/z 1068.3894 (M+Cs⁺,

C₄₅H₆₇N₇O₁₂F₂requires 1068.3870).

N,N⁰-Bis(N-(2-(4-methoxyphenyl)ethyl)carboxamido-

methyl)-N,N⁰-bis(N-(3,4,5-trimethoxybenzyl)carboxamido-

methyl)-N⁰⁰-((tert-butyloxy)carbonyl)iminodiacetic acid

diamide (16, A2B4): ¹H NMR (CDCl₃, 500 MHz) d

7.08 (m, 4H), 6.78 (m, 4H), 6.48 (m, 4H), 4.28 (m, 4H),

3.93 (m, 4H), 3.82±3.50 (m, 32H), 3.43 (m, 4H), 2.72 (m,

4H), 1.34 (m, 9H); IR (®lm) V_max3271, 3062, 2936,

1

15, A1B3C36: H NMR (CDCl₃, 400 MHz) d 7.20 (m,

27H), 6.80 (m, 9H), 4.50 (m, 6H), 3.80 (m, 30H), 3.50

(m, 30H), 2.80 (m, 12H), 2.20 (m, 1H); IR (®lm) V_max

3278, 2928, 2359, 1660, 1515, 1453, 1261, 1096,

1027 cm ¹; ESMS pos: M+H⁺1786, M+Na⁺1808;

neg: M H⁺1783, M+Cl 1819.

1667, 1592, 1512, 1462, 1329, 1248, 1126, 1033,

1

823 cm

; FABHRMS (NBA±CsI) m/z 1220.4132

(M+Cs⁺, C₅₅H₇₃N₇O₁₆requires 1220.4168).

1

15, A1B3C37: H NMR (CDCl₃, 400 MHz) d 7.55 (m,

9H), 7.25 (m, 15H), 6.90 (m, 6H), 6.75 (m, 9H), 4.60 (m,

6H), 4.10 (m, 5H), 3.80 (m, 25H), 3.50 (m, 12H), 2.80

(m, 12H); IR (®lm) V_max3274, 2932, 2360, 1659, 1518,

1453, 1235, 1026 cm ¹; ESMS pos: M+H⁺1674,

M+Na⁺1696; neg: M H⁺1672, M+Cl 1709.

N,N⁰-Bis(N-(2-(4-methoxyphenyl)ethyl)carboxamido-

methyl)-N,N⁰-bis(N,N-di(2-methoxyethyl)carboxamido-

methyl)-N⁰⁰-((tert-butyloxy)carbonyl)iminodiacetic acid

diamide (16, A2B6): ¹H NMR (CDCl₃, 500 MHz) d

7.10 (s, 4H), 6.80 (s, 4H), 4.40±3.65 (m, 14H), 3.60±3.30

(m, 36H), 2.75 (m, 4H), 1.33, (two s, 9H); IR (®lm) V_max

3263, 3066, 2937, 1664, 1592, 1512, 1459, 1423, 1329,

1246, 1176, 1129, 1012, 822, 734 cm ¹; FABHRMS

(NBA±CsI) m/z 1092.4302 (M+Cs⁺, C₄₇H₇₃N₇O₁₄

requires 1092.4270).

General procedure for 16: N,N⁰-bis(N-(2-(3,4-dimethoxy-

phenyl)ethyl)carboxamidomethyl)-N,N⁰-bis((N-((5-benzyl-

oxycarbonyl)amino)-5-(methoxycarbonyl)pentyl)carbox-

amidomethyl)-N⁰⁰-((tert-butyloxy)carbonyl)iminodiacetic

acid diamide (16, A7B3). A sample of 4 (A7B3, 3.36 g,

5.00 mmol) was stirred in a solution of 4 N HCl±dioxane

(26 mL) at 25 ^ꢀC for 4 h. ¹H NMR showed the dis-

appearance of the diagnostic BOC group (d 1.3, s, 9H).

Removal of the solvent under N₂and in vacuo gave the

deprotected material as a pale yellow solid, which was

dissolved in anhydrous DMF (20 mL). N-((tert-Buty-

N,N⁰-Bis(N-(2-(3-methoxyphenyl)ethyl)carboxamido-

methyl)-N,N⁰-bis((N-((5-benzyloxycarbonyl)amino)-5-

(methoxycarbonyl)pentyl)carboxamidomethyl)-N⁰⁰-((tert-

butyloxy)carbonyl)iminodiacetic acid diamide (16,

A7B2⁰⁰): ¹H NMR (CDCl₃, 400 MHz) d 7.27 (s, 10H),

7.12 (m, 2H), 6.68 (m, 6H), 5.60 (m, 2H), 5.02 (s, 4H),

4.23 (br m, 2H), 4.00 (m, 6H), 3.65 (m, 14H), 3.40 (m,

loxy)carbonyl)iminodiacetic

acid

(2,

0.388 g,

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1367

4H), 3.12 (m, 6H), 2.72 (m, 4H), 1.70 (m, 4H), 1.40 (br s,

4H) 1.39 (br s, 4H), 1.33 (s, 9H); IR (®lm) V_max3298,

N,N⁰-Bis(N-(4-(1⁰,4⁰-dioxolano)piperidino)carboxamido-

methyl)-N,N⁰-bis((N-((5-benzyloxycarbonyl)amino)-5-

(methoxycarbonyl)pentyl)carboxamidomethyl)-N⁰⁰-((tert-

butyloxy)carbonyl)iminodiacetic acid diamide (16,

A7B14): ¹H NMR (CDCl₃, 500 MHz) d 7.26 (s, 10H),

5.80±5.60 (m, 2H), 5.06 (s, 4H), 4.20±3.80 (m, 18H), 3.60

(m, 10H), 3.33±3.13 (m, 14H), 1.68 (m, 8H), 1.45 (m,

4H), 1.39 (m, 13H); IR (®lm) V_max3275, 2955, 2871,

3068, 2949, 1657, 1546, 1454, 1258, 1166, 1038, 845, 739,

1

698 cm

; FABHRMS (NBA±NaI) m/z 1304.6143

(M+Na⁺, C₆₅H₈₇N₉O₁₈requires 1304.6066).

N,N⁰-Bis(N-(3,4,5-trimethoxybenzyl)carboxamidomethyl)-

N,N⁰-bis((N-((5-benzyloxycarbonyl)amino)-5-(methoxy-

carbonyl)pentyl)carboxamidomethyl)-N⁰⁰-((tert-butyloxy)-

carbonyl)iminodiacetic acid diamide (16, A7B4): ¹H

NMR (CDCl₃, 500 MHz) d 7.28 (s, 10H), 6.55 (s, 4H),

5.90±5.70 (m, 2H), 5.06 (s, 4H), 4.35 (br s, 8H), 4.10±

3.60 (m, 34H), 3.20 (br s, 2H), 1.80 (m, 4H), 1.60 (m,

4H), 1.34 (m, 13H); IR (®lm) V_max3291, 3070, 2941,

1658, 1535, 1453, 1402, 1365, 1337, 1211, 1165, 1015,

1

843 cm

; FABHRMS (NBA±NaI) m/z 1288.5892

(M+Na⁺, C₆₁H₈₇N₉O₂₀requires 1288.5965).

N,N⁰-Bis(N-(2-furanyl)methylcarboxamidomethyl)-N,N⁰-

bis((N-((5-benzyloxycarbonyl)amino)-5-(methoxycarbonyl)-

pentyl)carboxamidomethyl)-N⁰⁰-((tert-butyloxy)carbonyl)-

iminodiacetic acid diamide (16, A7B15): ¹H NMR

(CDCl₃, 500 MHz) d 7.23 (m, 10H), 6.20 (m, 6H), 5.70

(m, 2H), 5.00 (s, 4H), 4.38±4.18 (m, 6H), 4.10±3.72 (m,

12H), 3.70±3.50 (m, 6H), 3.12 (s, 2H), 1.68 (m, 4H), 1.48

(m, 4H), 1.39 (m, 4H), 1.34 (s, 9H); IR (®lm) V_max3292,

1659, 1592, 1460, 1329, 1234, 1120, 1005, 845, 739,

1

699 cm

; FABHRMS (NBA±CsI) m/z 1506.5428

(M+Cs⁺, C₆₇H₉₁N₉O₂₂requires 1506.5333).

N,N⁰-Bis(N-(2-(4-¯uorophenyl)ethyl)carboxamidomethyl)-

N,N⁰-bis((N-((5-benzyloxycarbonyl)amino)-5-(methoxy-

carbonyl)pentyl)carboxamidomethyl)-N⁰⁰-((tert-butyloxy)-

carbonyl)iminodiacetic acid diamide (16, A7B13): ¹H

NMR (CDCl₃, 500 MHz) d 7.28 (s, 10H), 7.08 (br s,

4H), 6.86 (m, 4H), 5.83 (m, 2H), 5.04 (s, 4H), 4.26 (br s,

2H), 4.02±3.63 (m, 10H), 3.62±3.42 (m, 6H), 3.35 (m,

4H), 3.15 (br s, 4H), 2.70 (br s, 4H), 1.72 (m, 4H), 1.48

(br s, 4H), 1.33 (br s, 13H); IR (®lm) V_max3295, 3069,

3065, 2950, 2869, 2667, 1544, 1455, 1402, 1368, 1343,

1

1253, 1212, 1164, 1081, 1016, 845, 738, 699 cm

;

FABHRMS (NBA±NaI) m/z 1196.5199 (M+Na⁺,

C₅₇H₇₅N₉O₁₈requires 1196.5127).

General procedure for the synthesis of individual

sublibrary entries for 17: A2B4C43. The BOC derivative

16, A2B4 (0.104 g, 0.11 mmol) was stirred in a solution

of 4 N HCl±dioxane (1 mL) at 25 ^ꢀC for 4 h. Removal of

the solvent under N₂and in vacuo gave the deprotected

material as a pale yellow solid, which was dissolved in

anhydrous DMF (0.5 mL). Diglycolic acid (C43,

4.97 mg, 0.037 mmol), i-Pr₂NEt (0.058 mL, 0.33 mmol)

and PyBrOP (51.9 mg, 0.11 mmol) were added sequen-

tially. The reaction mixture was stirred for 16 h at

25 ^ꢀC before being diluted with EtOAc (50 mL) and

washed with 10% aqueous HCl (2Â50 mL), saturated

aqueous NaHCO₃(2Â50 mL), saturated aqueous NaCl

(50 mL) and dried (Na₂SO₄). The solvent was removed

under reduced pressure to provide 42.3 mg (65%) of

the title substance as an oil: ¹H NMR (CDCl₃,

500 MHz) d 7.08 (m, 8H), 6.75 (m, 8H), 6.50 (m, 8H),

(br s, 8H), 4.30 (m, 8H), 4.05±3.61 (m, 68H), 3.50 (m,

8H), 2.71 (m, 8H); IR (®lm) V_max3263, 3071, 2937,

2946, 1660, 1547, 1510, 1455, 1253, 1220, 1160, 1046,

1

845, 739, 699 cm

1280.5596

1280.5667).

;

FABHRMS (NBA±NaI) m/z

C₆₃H₈₁N₉O₁₆F₂requires

(M+Na⁺,

N,N⁰-Bis(N,N-di(2-methoxyethyl)carboxamidomethyl)-

N,N⁰-bis((N-((5-benzyloxycarbonyl)amino)-5-(methoxy-

carbonyl)pentyl)carboxamidomethyl)-N⁰⁰-((tert-butyloxy)-

carbonyl)iminodiacetic acid diamide (16, A7B6): ¹H

NMR (CDCl₃, 500 MHz) d 7.21 (s, 10H), 5.80±5.60 (m,

2H), 5.06 (s, 4H), 4.50±3.80 (m, 14H), 3.62 (s, 4H), 3.45

(m, 18H), 3.28 (m, 12H), 1.70 (m, 4H), 1.45 (br s, 4H),

1.30 (m, 13H); IR (®lm) V_max3290, 3066, 2936, 1651,

1

1537, 1454, 1271, 1231, 1118, 845, 739, 700 cm

FABHRMS (NBA±CsI) m/z 1378.5513 (M+Cs,

;

C₅₉H₉₁N₉O₂₀requires 1378.5435).

N,N⁰-Bis(N,N⁰-(2-(2-thienyl)ethyl)carboxamidomethyl)-

N,N⁰-bis((N-((5-benzyloxycarbonyl)amino)-5-(methoxy-

carbonyl)pentyl)carboxamidomethyl)-N⁰⁰-((tert-butyloxy)-

carbonyl)iminodiacetic acid diamide (16, A7B8⁰): ¹H

NMR (CDCl₃, 500 MHz) d 8.80±7.40 (m, 4H), 7.25 (s,

10H), 7.02 (s, 2H), 6.82 (s, 2H), 6.72 (s, 2H), 5.82 (m,

2H), 5.06 (s, 4H), 4.22 (s, 2H), 4.10±3.32 (m, 22H), 3.22

(m, 4H), 2.90 (m, 4H), 1.68 (m, 4H), 1.55 (m, 4H), 1.40

2837, 1668, 1592, 1512, 1461, 1424, 1329, 1246, 1178,

1

1126, 1032, 1006, 964, 823 cm

; MALDI±FTMS

(NBA±NaI) m/z 2095.9087 (M+Na⁺, C₁₀₄H₁₃₂N₁₄O₃₁

requires 2095.9081).

17, A2B4C1: ¹H NMR (CDCl₃, 500 MHz) d 7.08 (m,

8H), 6.72 (m, 8H), 6.49 (m, 8H), 4.30 (br s, 8H), 4.09±

3.65 (m, 72H), 3.45 (br s, 8H), 2.70 (m, 8H); IR (®lm)

V_max3279, 3073, 2937, 2837, 1652, 1592, 1512, 1463,

1423, 1329, 1301, 1245, 1126, 1032, 1005, 965, 824,

733 cm ¹; MALDI±FTMS (NBA±NaI) m/z 2075.8848

(M+Na⁺, C₁₀₄H₁₂₈N₁₄O₃₀requires 2075.8818).

(m, 13H); IR (®lm) V_max3291, 3065, 2945, 1660, 1537,

1

1454, 1402, 1252, 1164, 1045, 846, 737, 697 cm

;

FABHRMS (NBA±CsI) m/z 1234.5097 (M+H⁺,

C₅₉H₇₉N₉O₁₆S₂requires 1234.5164).

1368

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

17, A2B4C2: ¹H NMR (CDCl₃, 500 MHz) d 7.06 (m,

8H), 6.77 (m, 8H), 6.54 (m, 8H), 4.37±3.84 (m, 18H),

3.83±3.67 (m, 64H), 3.42 (br s, 8H), 2.70 (br s, 8H); IR

1423, 1329, 1303, 1245, 1126, 1031, 999, 965, 821,

735 cm ¹; MALDI±FTMS (NBA±NaI) m/z 2133.9620

(M+Na⁺, C₁₀₈H₁₃₈N₁₄O₃₀requires 2133.9601).

(®lm) V_max3274, 3067, 2937, 2836, 1659, 1592, 1512,

1

1462, 1423, 1328, 1244, 1193, 1126, 1032, 966, 822 cm

;

17, A2B4C9: ¹H NMR (CDCl₃, 500 MHz) d 7.06 (m,

8H), 6.78 (m, 8H), 6.51 (m, 8H), 4.33 (m, 8H), 4.12±3.67

(m, 72H), 3.40 (m, 8H), 2.72 (m, 8H), 2.50±1.20 (m,

10H); IR (®lm) V_max3266, 3074, 2939, 2827, 1656, 1592,

1512, 1462, 1423, 1328, 1300, 1245, 1126, 1030, 964,

844 cm ¹; MALDI±FTMS (NBA±NaI) m/z 2133.9516

(M+Na⁺, C₁₀₈H₁₃₈N₁₄O₃₀requires 2133.9601).

MALDI±FTMS (NBA±NaI) m/z 2077.8980 (M+Na⁺,

C₁₀₄H₁₃₀N₁₄O₃₀requires 2077.8975).

1

17, A2B4C3: H NMR (CDCl₃, 500 MHz) d 7.07 (br s,

8H), 6.78 (m, 8H), 6.52 (m, 8H), 4.32 (br s, 8H), 4.16±

3.69 (m, 74H), 3.41 (br s, 8H), 2.72 (m, 8H), 2.42 (s,

4H); IR (®lm) V_max3279, 3062, 2932, 2832, 1652, 1593,

1557, 1512, 1463, 1423, 1329, 1298, 1244, 1183, 1126,

1028, 1004, 969, 824 cm ¹; MALDI±FTMS (NBA±NaI)

m/z 2105.9273 (M+Na⁺, C₁₀₆H₁₃₄N₁₄O₃₀requires

2105.9287).

1

17, A2B4C10: H NMR (CDCl₃, 500 MHz) d 7.08 (m,

8H), 6.79 (m, 8H), 6.52 (m, 8H), 4.32 (m, 8H), 4.17±3.68

(m, 72H), 3.41 (m, 8H), 2.70 (m, 8H), 2.50±1.20 (m,

10H); IR (®lm) V_max3272, 3073, 2938, 2827, 1651, 1593,

1557, 1512, 1463, 1423, 1329, 1301, 1245, 1182, 1126,

1031, 1003, 964, 823, 733 cm ¹; MALDI±FTMS (NBA±

NaI) m/z 2133.9574 (M+Na⁺, C₁₀₈H₁₃₈N₁₄O₃₀

requires 2133.9601).

1

17, A2B4C4: H NMR (CDCl₃, 500 MHz) d 8.60±7.20

(m, 4H), 7.06 (br s, 8H), 6.67 (m, 8H), 6.54 (m, 8H), 4.32

(m, 8H), 4.12±3.69 (m, 72H), 3.40 (m, 8H), 2.72 (m, 8H);

IR (®lm) V_max3268, 3076, 2936, 2838, 1651, 1592, 1557,

1512, 1462, 1423, 1329, 1298, 1244, 1178, 1125, 1031,

999, 964, 822 cm ¹; MALDI±FTMS (NBA±NaI) m/z

17, A2B4C41: ¹H NMR (CDCl₃, 500 MHz) d 7.02 (br s,

8H), 6.75 (br s, 8H), 6.52 (br s, 8H), 4.30 (br s, 8H),

4.10±3.70 (m, 72H), 3.40 (br s, 8H), 2.71 (br s, 8H), 2.02

2127.9107

2127.9131).

(M+Na⁺,

C₁₀₈H₁₃₂N₁₄O₃₀

requires

(br s, 8H); IR (®lm) V_max3270, 3077, 2936, 1658, 1592,

1

1512, 1461, 1423, 1329, 1245, 1126, 1033, 964, 733 cm

;

1

17, A2B4C5: H NMR (CDCl₃, 500 MHz) d 8.31±7.20

(m, 4H), 7.08 (m, 8H), 6.78 (m, 8H), 6.54 (m, 8H), 4.32

(br s, 8H), 4.12±3.68 (m, 72H), 3.38 (m, 8H), 2.72 (m,

8H); IR (®lm) V_max3266, 3067, 2939, 2828, 1652, 1592,

1557, 1512, 1461, 1423, 1328, 1298, 1244, 1183, 1126,

1024, 1003, 959, 821 cm ¹; MALDI±FTMS (NBA±NaI)

m/z 2127.9062 (M+Na⁺, C₁₀₈H₁₃₂N₁₄O₃₀requires

2127.9131).

FABHRMS (NBA±CsI) m/z 2246.8790 (M+Cs⁺+¹³C,

C

₁₀₇H₁₃₆N₁₄O₃₁requires 2246.8584).

17, A2B4C42: ¹H NMR (CDCl₃, 500 MHz) d 7.02 (br s,

8H), 6.75 (br s, 8H), 6.52 (br s, 8H), 4.30 (br s, 8H),

4.10±3.70 (m, 72H), 3.40 (br s, 8H), 2.71 (br s, 8H), 2.02

(m, 8H), 1.60 (br s, 4H); IR (®lm) V_max3270, 3075,

2937, 1658, 1592, 1512, 1462, 1422, 1328, 1244, 1181,

1126, 1033, 823, 734 cm ¹; FABHRMS (NBA±CsI) m/

1

17, A2B4C6: H NMR (CDCl₃, 500 MHz) d 8.10±7.20

z

2274.9110 (M+Cs⁺+¹³C, C₁₀₉H₁₄₀N₁₄O₃₁requires

2274.8897).

(m, 6H), 7.05 (m, 8H), 6.79 (m, 8H), 6.51 (m, 8H), 4.30

(br s, 8H), 4.08±3.68 (m, 72H), 3.40 (m, 8H), 2.72 (m,

8H); IR (®lm) V_max3273, 3074, 2937, 2837, 1655, 1593,

17, A2B4C44: ¹H NMR (CDCl₃, 500 MHz) d 7.02 (br s,

8H), 6.75 (br s, 8H), 6.52 (br s, 8H), 4.30 (br s, 8H),

4.10±3.70 (m, 80H), 3.40 (br s, 8H), 2.71 (br s, 8H); IR

(®lm) V_max3270, 3069, 2937, 2837, 1657, 1592, 1512,

1512, 1463, 1423, 1328, 1298, 1244, 1195, 1126, 1030, 1009,

1

964, 826 cm

;

MALDI±FTMS (NBA±NaI) m/z

2181.9350 (M+Na⁺, C₁₁₂H₁₃₄N₁₄O₃₀requires 2181.9600).

1461, 1423, 1328, 1244, 1182, 1126, 1032, 964, 823,

1

17, A2B4C7: ¹H NMR (CDCl₃, 500 MHz) d 7.08 (m,

8H), 6.79 (m, 8H), 6.52 (m, 8H), 4.33 (br s, 8H), 4.08±

3.69 (m, 72H), 3.42 (m, 8H), 2.72 (m, 8H), 2.50±1.20 (m,

10H); IR (®lm) V_max3277, 3076, 2935, 2838, 1652, 1592,

1557, 1512, 1463, 1423, 1328, 1298, 1244, 1178, 1126,

1033, 959, 869, 822 cm ¹; MALDI±FTMS (NBA±NaI)

m/z 2133.9500 (M+Na⁺, C₁₀₈H₁₃₈N₁₄O₃₀requires

2133.9601).

733 cm

;

FABHRMS (NBA±CsI) m/z 2249.8351

(M+Cs⁺, C₁₀₆H₁₃₆N₁₄O₃₂requires 2249.8499).

17, A2B4C45: ¹H NMR (CDCl₃, 500 MHz) d 7.02 (br s,

8H), 6.75 (br s, 8H), 6.52 (br s, 8H), 4.30 (br s, 8H),

4.10±3.70 (m, 84H), 3.40 (br s, 8H), 2.71 (br s, 8H); IR

(®lm) V_max3291, 2938, 1659, 1592, 1512, 1462, 1423,

1328, 1244, 1126, 845 cm ¹; FABHRMS (NBA±CsI)

m/z 2293.8973 (M+Cs⁺, C₁₀₈H₁₄₀N₁₄O₃₃requires

2293.8762).

17, A2B4C8: ¹H NMR (CDCl₃, 500 MHz) d 7.07 (m,

8H), 6.79 (m, 8H), 6.53 (m, 8H), 4.32 (m, 8H), 4.12±3.69

(m, 72H), 3.40 (m, 8H), 2.73 (m, 8H), 2.50±1.20 (m,

10H); IR (®lm) V_max3275, 2938, 1654, 1593, 1512, 1451,

17, A2B4C46: ¹H NMR (CDCl₃, 500 MHz) d 7.01 (br s,

8H), 6.78 (br s, 8H), 6.51 (br s, 8H), 4.30 (br s, 8H),

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1369

4.10±3.70 (m, 86H), 3.40 (br s, 10H), 2.71 (br s, 8H); IR

(®lm) V_max3507, 3263, 3072, 2936, 2837, 1667, 1592,

1557, 1512, 1462, 1423, 1329, 1301, 1246, 1178, 1129,

1032, 1006, 965, 901, 824, 733 cm ¹; MALDI±FTMS

(NBA±NaI) m/z 2227.9926 (M+Na⁺, C₁₁₀H₁₄₄N₁₄O₃₄

requires 2227.9867).

(25 mL) washed with 20% aqueous HCl saturated with

NaCl (3Â25 mL), saturated aqueous NaHCO₃

(1Â25 mL) and saturated aqueous NaCl (1Â25 mL),

dried (Na₂SO₄) and concentrated to aord 60 mg (90%)

of the sublibrary. MS exhibited all the expected mole-

cular ion for 17, A2B4CI±C10: MALDI±MS (M+H⁺

or M+Na⁺) m/z 2050, 2052, 2079, 2106, 2129, 2180 (10

components, 6 dierent molecular weights). Similarly,

for 17, A2B4C41±C50, the yield is 71%. MS exhibited all

the expected molecular ions: MALDI±MS (M+H⁺or

M+Na⁺) m/z 2090, 2094, 2134, 2138, 2162, 2182, 2186,

2226, 2244, 2270. A summary of the individual and

mixture coupling yields is provided in Table 7.

17, A2B4C47: ¹H NMR (CDCl₃, 500 MHz) d 7.02 (br s,

8H), 6.73 (br s, 8H), 6.50 (br s, 8H), 4.32 (m, 8H), 4.12±

3.70 (m, 90H), 3.40 (br s, 10H), 2.71 (br s, 8H); IR (®lm)

V_max3507, 3264, 3071, 2935, 2837, 1741, 1670, 1611,

1592, 1561, 1542, 1461, 1424, 1367, 1329, 1301, 1246,

1

1178, 1163, 1128, 1032, 1006, 964, 901, 823 cm

;

MALDI±FTMS (NBA±NaI) m/z 2272.0250 (M+Na⁺,

C

₁₁₂H₁₄₈N₁₄O₃₅requires 2272.0129).

Similarly, seven tetra-amides 16: A6B6, A2B4, A2B6,

A7B15, A7B4, A7B6, A7B14 have been individually

coupled with each of the eight diacids in group C21±C28,

1

17, A6B6C48: H NMR (CDCl₃, 500 MHz) d 7.12 (m,

8H), 6.92 (m, 8H), 4.43±3.70 (m, 20H), 3.50±3.18 (m,

70H), 2.78 (m, 8H); IR (®lm) V_max3278, 2932, 1654,

1508, 1457, 1220, 1117, 824, 668 cm ¹; FABHRMS

(NBA±CsI) m/z 1917.7758 (M+Cs⁺, C₈₄H₁₂₀N₁₄O₂₄F₄

requires 1917.7590).

1

so that 56 single compounds of 17 have been made. H

NMR of each ensured the integrity of each compound

and full characterization has been carried out on

A6B6C21, A2B6C26 and A2B4C28.

17, A6B6C21: ¹H NMR (CDCl₃, 500 MHz) d 7.08 (br s,

8H), 6.91 (br s, 8H), 4.48±3.75 (m, 24H), 3.57±3.12 (m,

64H), 2.70 (br s, 8H), 1.45 (br s, 4H), 1.19 (m, 8H); IR

1

17, A2B4C49: H NMR (CDCl₃, 500 MHz) d 7.03±6.75

(two br s, 20H), 6.45 (m, 8H), 4.29 (br s, 8H), 4.10±3.60

(m, 76H), 3.35 (m, 8H), 2.70 (br s, 8H); IR (®lm) V_max

3568, 3268, 3071, 2936, 2837, 1743, 1670, 1611, 1592,

(®lm) V_max3272, 3073, 2932, 1655, 1560, 1509, 1471,

1

1219, 1194, 1158, 1117, 1015, 965, 843 cm

;

1560, 1548, 1461, 1424, 1367, 1329, 1301, 1246, 1178,

1

FABHRMS (NBA±CsI) m/z 1941.8205 (M+Cs⁺,

C₈₈H₁₂₈N₁₄O₂₂F₄requires 1941.8318).

1126, 1031, 1006, 965, 901, 823, 779, 733, 668 cm

;

MALDI-FTMS (NBA±NaI) m/z 2187.9455 (M+Na⁺,

1

C₁₁₀H₁₃₆N₁₄O₃₂requires 2187.9343).

17, A2B6C26: H NMR (CDCl₃, 500 MHz) d 7.10 (m,

8H), 6.78 (m, 8H), 4.55±3.78 (s, 28H), 3.55±3.18 (m,

72H), 2.72 (m, 8H), 1.60 (br s, 4H), 1.23 (br s, 28H); IR

(®lm) V_max3439, 2925, 2852, 1654, 1513, 1465, 1300,

1246, 1193, 1116, 1032, 962, 844 cm ¹; FABHRMS

(NBA±CsI) m/z 2130.0541 (M+Cs⁺, C₁₀₂H₁₆₀N₁₄O₂₆

requires 2130.0683).

17, A2B4C50: ¹H NMR (CDCl₃, 500 MHz) d 7.02 (br s,

8H), 6.75 (br s, 8H), 6.52 (br, 8H), 4.30 (br s, 8H), 4.10±

3.70 (m, 80H), 3.40 (br s, 8H), 2.71 (br s, 8H), 2.01 (s,

6H); IR (®lm) V_max3278, 3068, 2937, 2837, 1657, 1592,

1512, 1461, 1423, 1328, 1244, 1195, 1126, 1031,

1

841 cm

, FABHRMS (NBA±CsI) m/z 2355.9190

1

(M+Cs⁺, C₁₁₂H₁₄₂N₁₆O₃₂requires 2355.9030).

17, A2B4C28: H NMR (CDCl₃, 500 MHz) d 7.03 (br

s, 8H), 6.72 (br s, 8H), 6.60 (m, 8H), 4.31 (br s, 8H),

General procedure for 17 (C1±C10 and C41±C50): sub-

library A2B4C1±10 and A2B4C41±50. CHCl₃(1 mL) and

4 N HCl±dioxane (1 mL) were added to 16, A2B4

(0.1041 g, 0.09577 mmol) in a 4 mL vial and this mixture

was allowed to stand for 4 h at 25 ^ꢀC. TLC (15%

CH₃OH±EtOAc) then indicated that conversion to the

amine was complete. The solvent and excess acid were

removed by evaporation. A stock solution was prepared

by diluting a mixture of 0.5 mmol of each diacid (C1±

C10 and C41±C50), and 45 mmol of i-Pr₂NEt to 100 mL

in anhydrous DMF. This stock solution (0.638 mL,

0.00318 mmol of each diacid, 0.45 mmol of i-Pr₂NEt)

was added to the diamide and the mixture was shaken to

eect dissolution. PyBrOP (44.7 mg, 0.096 mmol) was

added and the mixture was capped and stirred for 12 h at

25 ^ꢀC. The reaction mixture was diluted with EtOAc

Table 7. Representative individual and mixture coupling

yields, 17

A2B4C1

A2B4C2

A2B4C3

A2B4C4

A2B4C5

A2B4C6

A2B4C7

A2B4C8

A2B4C9

A2B4C10

average

95%

78%

93%

78%

80%

78%

69%

76%

95%

84%

92%

A2B4C41

A2B4C42

A2B4C43

A2B4C44

A2B4C45

A2B4C46

A2B4C47

A2B4C48

A2B4C49

A2B4C50

average

80%

77%

79%

41%

62%

59%

79%

48%

40%

44%

61%

71%

A2B4C1±10

A2B4C41±50

1370

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

4.10±3.67 (m, 72H), 3.32 (br s, 8H), 2.72 (br s, 8H), 1.40

(br m, 4H), 1.20 (m, 36H); IR (®lm) V_max3046, 3073,

2924, 2849, 1656, 1593, 1512, 1462, 1423, 1329, 1301,

1245, 1180, 1126, 953, 844, 556 cm ¹; FABHRMS

(NBA±CsI) m/z 2442.1273 (M+Cs⁺, C₁₂₂H₁₆₈N₁₄O₃₀

requires 2442.1105).

molecular ions (10 dierent components which have

eight dierent molecular weights): ESMS (M+Cl ) m/z

2184, 2034, 2009, 2007, 1985, 1976, 1964, 1933.

1

Selected characterization for 5, AXB10C4 (A scan). H

NMR of each of the 114 compounds, A8B10C4±

A123B10C4, ensured the integrity of each compound in

the A scan. Full characterization has been carried out

on the following 11 compounds.

General procedure for the synthesis of individual

sublibrary entries for 17: preparation of A2B1C19. The

BOC derivative 16 (A2B1, 82 mg, 0.078 mmol) was stir-

red in a solution of 4 N HCl±dioxane (2 mL) at 25 ^ꢀC for

4 h. Removal of the solvent under N₂and in vacuo gave

the deprotected material as a yellow oil. The crude

amine hydrochloride was dissolved in anhydrous

DMF (2 mL) and C19 (10 mg, 0.026 mmol), i-Pr₂NEt

1

5, A8B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

(m, 4H), 7.29 (s, 10H), 5.80 (m, 2H), 5.05 (s, 4H), 4.30

(br s, 4H), 4.15±3.40 (m, 20H), 3.20 (m, 4H), 2.60±2.20

(m, 6H), 1.90±1.30 (m, 20H); IR (®lm) V_max3288, 2946,

1

1715, 1643, 1535, 1453, 1237, 1102, 1028 cm

;

(0.041 mL,

0.234 mmol)

and PyBrOP (36 mg,

FABHRMS (NBA±CsI) m/z 1331.4420 (M+Cs⁺,

C₆₀H₇₈N₈O₁₈requires 1331.4488).

0.078 mmol) were added sequentially. The mixture was

stirred for 16 h at 25^ꢀbefore being diluted with EtOAc

(20 mL) and washed with 10% aqueous HCl (2Â20 mL),

saturated aqueous NaHCO₃(2Â20 mL), saturated aqu-

eous NaCl (20 mL), and dried (Na₂SO₄). The solvent

was removed under reduced pressure to provide 39 mg

(66%) of the title substance as an oil: ¹H NMR (CDCl₃,

400 MHz) d 7.38±7.25 (m, 4H), 7.08±7.05 (m, 8H), 6.80±

6.65 (m, 24H), 4.11±3.68 (m, 60H), 3.45 (m, 16H), 2.80

(m, 16H); IR (®lm) V_max3282, 3067, 2923, 2831, 1651,

1569, 1508, 1462, 1246, 1221, 1174, 1036, 969, 841, 810,

733, 703 cm ¹; FABHRMS (NBA±CsI) m/z 2399.8858

(M+Cs⁺, C₁₁₇H₁₃₆F₆N₁₄O₂₆requires 2399.8709).

1

5, A12B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

(m, 4H), 7.25(s, 10H), 7.10 (m, 2H), 6.75 (m, 4H), 5.60±

5.40 (m, 2H), 5.02 (br s, 4H), 4.23±3.80 (m, 8H), 3.60 (br

s, 6H), 3.40±2.70 (m, 12H), 1.80±1.30 (m, 12H); IR

(®lm) V_max3288, 2934, 1651, 1540, 1454, 1249, 1026,

1

698 cm

; FABHRMS (NBA±CsI) m/z 1299.3571

(M+Cs⁺, C₅₈H₇₀N₈O₁₄S, requires 1299.3507).

1

5, A13B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

(m, 4H), 7.31 (s, 12H), 6.30 (m, 4H), 5.78 (br s, 2H),

5.06 (s, 4H), 4.40±4.30 (m, 6H), 4.10±3.80 (m, 6H), 3.70

(s, 6H), 3.20 (m, 4H), 1.80 (m, 4H), 1.41 (m, 4H), 1.35

(m, 4H); IR (®lm) V_max3278, 3055, 2949, 1658, 1545,

1453, 1248, 1025, 739, 699 cm ¹; FABHRMS (NBA±

CsI) m/z 1239.3589 (M+Cs⁺, C₅₆H₆₆N₈O₁₆requires

1239.3651).

1

17, A2B11C14: H NMR (CDCl₃, 400 MHz) d 7.96 (m,

2H), 7.50 (m, 4H), 7.25±7.05 (m, 28H), 6.80±6.74 (m,

8H), 4.10±3.70 (m, 36H), 3.46 (m, 16H), 2.80 (m, 16H);

IR (®lm) V_max3282, 3067, 2923, 1651, 1574, 1513, 1456,

1301, 1246, 1179, 1031, 823, 739 cm ¹; FABHRMS

(NBA±CsI) m/z 1983.7941 (M+Cs⁺, C₁₀₄H₁₁₈N₁₄O₁₈

requires 1983.7803).

1

5, A15B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

(m, 4H), 7.29 (br s, 10H), 5.65 (m, 2H), 5.05 (s, 4H),

4.30 (m, 4H), 4.15±3.60 (m, 16H), 3.30±2.50 (m, 10H),

1.95±1.40 (m, 8H), 1.40±1.30 (m, 20H); IR (®lm) V_max

2948, 1720, 1636, 1453, 1213, 1039 cm ¹; FABHRMS

(NBA±CsI) m/z, 1359.4871 (M+Cs⁺, C₆₂H₈₂N₈O₁₈

requires 1359.4801).

General procedure for 17: sublibrary A2B2⁰⁰C11±20. The

BOC derivative 16 (A2B2⁰⁰, 55 mg, 0.0552 mmol) was

stirred in a solution of 4 N HCl±dioxane (2 mL) at 25 ^ꢀC

for 4 h. Removal of the solvent under N₂and in vacuo

gave the deprotected material as a yellow oil. A diacid

stock solution was prepared through diluting a mixture

of 0.5 mmol of each diacid C11±C20 to 80 mL DMF and

20 mL DMSO. The crude amine hydrochloride was dis-

solved in anhydrous DMF (2 mL), and the diacid stock

solution (0.368 mL, 0.0184 mmol of C11±C20), i-Pr₂NEt

(0.029 mL, 0.166 mmol) and PyBrOP (26 mg, 0.0552

mmol) were added sequentially. The reaction mixture

was stirred for 16 h at 25 ^ꢀC before being diluted with

EtOAc (20 mL) and washed with 10% aqueous HCl

(2Â20 mL), saturated aqueous NaHCO₃(2Â20 mL),

and dried (Na₂SO₄). The solvent was removed under

reduced pressure to provide 30 mg (83%) of the title

substance as an oil. The MS exhibited all the expected

1

5, A29B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

(m, 4H), 7.50±7.05 (m, 20H), 5.70 (m, 2H), 5.02 (s, 4H),

4.50±3.45 (m, 22H), 3.20 (m, 4H), 2.50 (m, 4H), 1.90±

1.35 (m, 22H); IR (®lm) V_max3276, 2930, 1718, 1637,

1452, 1249, 842 cm ¹; FABHRMS (NBA±CsI) m/z

1395.5390 (M+Cs⁺, C₇₀H₈₆N₈O₁₄requires 1395.5318).

1

5, A33B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.55

(m, 4H), 7.50±6.85 (m, 30H), 5.60 (m, 2H), 5.02 (s, 4H),

4.80 (m, 4H), 4.30±3.30 (m, 18H), 1.80±1.30 (m, 12H);

IR (®lm) V_max3288, 2944, 1716, 1648, 1540, 1496, 1454,

1267, 1028, 700 cm ¹; FABHRMS (NBA±CsI) m/z

1411.4617 (M+Cs⁺, C₇₂H₇₈N₈O₁₄requires 1411.4692).

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1371

1

5, A38B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

viscous oil: ¹H NMR (CD₃OD, 400 MHz) d 7.31 (m,

24H), 5.16 (s, 4H), 5.13 (s, 4H), 4.32 (s, 4H), 4.08 (s,

4H); ¹³C NMR (CD₃OD, 100 MHz) d 171.4, 168.8,

168.6, 135.2, 135.1, 134.8, 129.1, 128.7, 128.6, 128.7,

125.5, 67.5, 67.2, 51.8, 47.8; IR (®lm) V_max1747, 1655,

1455, 1185 cm ¹; FABHRMS (NBA±CsI) m/z 889.1759

(M+Cs⁺, C₄₄H₄₀N₂O₁₀requires 889.1737).

(m, 4H), 7.30 (m, 10H), 6.70 (m, 6H), 5.90±5.60 (m, 6H),

5.01 (s, 4H), 4.30±3.50 (m, 18H), 3.28 (m, 4H), 1.80±1.20

(m, 12H); IR (®lm) V_max3287, 3056, 2924, 1718, 1648,

1544, 1490, 1444, 1250, 1037, 662 cm ¹; FABHRMS

(NBA±CsI) m/z 1347.3794 (M+Cs⁺, C₆₂H₇₀N₈O₁₈

requires 1347.3862).

1

5, A51B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

N,N⁰-Bis(N,N-di(carboxymethyl))benzene-1,3-dicarbox-

amide (19). A solution of 18 (5.5 g, 7.8 mmol) in THF±

EtOH (100 mL, 1:1) was treated with 10% Pd±C

(500 mg), and the suspension was stirred under a H₂

atmosphere for 6 h at 25 ^ꢀC. The mixture was ®ltered

through a pad of Celite and the solvent removed in

vacuo to provide 19 (2.9 g, 95%) as a white foam: ¹H

NMR (CD₃OD, 400 MHz) d 7.40 (m, 4H), 5.25 (br s,

8H), 4.28 (s, 4H), 4.05 (s, 4H); ¹³C NMR (CD₃OD,

(m, 4H), 8.65 (br s, 2H), 8.45 (br s, 2H), 8.24 (br s, 2H),

7.56 (two s, 6H), 7.28 (br s, 10H), 5.80 (m, 2H), 5.02 (br

s, 4H), 4.28 (br s, 2H), 3.70 (br s, 6H), 3.20 (br s, 10H),

2.80 (s, 8H), 1.80±1.10 (m, 28H); IR (®lm) V_max3263,

1

2933, 1648, 1454, 1324, 1163, 1138, 1013, 793 cm

;

FABHRMS (NBA±CsI) m/z 1725.4730 (M+Cs⁺,

C₇₈H₉₄Cl₂N₁₀O₁₈S₂requires 1725.4620).

1

5, A52B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

100 MHz) d 173.6, 172.2, 172.1, 136.9, 130.4, 129.4,

1

(m, 4H), 7.30 (m, 22H), 5.56 (m, 2H), 5.05 (m, 4H), 4.30

(br s, 4H), 3.65 (m, 10H), 3.30 (m, 6H), 2.20 (m, 6H),

1.78 (m, 4H), 1.48 (br s, 4H), 1.30 (br s, 4H); IR (®lm)

V_max3275, 2948, 1683, 1582, 1528, 1491, 1452, 1402,

1266, 1092, 1015, 686 cm ¹; FABHRMS (NBA±CsI)

m/z 1625.3360 (M+Cs⁺, C₇₆H₇₆Cl₄N₁₀O₁₄requires

1625.3351).

126.1, 52.8; IR (®lm) V_max2998, 1728, 1620, 1225 cm

;

FABHRMS (NBA±NaI) m/z 397.0875 (M+H⁺,

C₁₆H₁₆N₂O₁₀requires 397.0883).

N,N⁰-Bis(N-(carboxymethyl))-N,N⁰-bis(N-2-(4-¯uoro-

phenyl)ethyl)carboxamidomethyl)benzene-1,3-dicarbox-

amide (20). A solution of 19 (1.6 g, 3.9 mmol) in DMF

(20 mL) was treated with EDCI (1.6 g, 8.0 mmol). After

stirring for 1 h at 25 ^ꢀC, 4-¯uorophenethylamine

(1.0 mL, 8.0 mmol) was added and the mixture was stir-

red for another 4 h. The solvent was removed in vacuo,

and ¯ash chromatography (SiO₂, 1% HOAc, 5%

CH₃OH±CHCl₃) aorded 20 (1.7 g, 70%) as a white

foam: ¹H NMR (CD₃OD, 400 MHz) d 7.50 (m, 4H),

7.22 (m, 4H), 6.98 (m, 4H), 4.20±3.98 (m, 8H), 3.38 (t,

4H, J=7.3 Hz), 2.77 (t, 4H, J=7.3 Hz); ¹³C NMR

(CD₃OD, 100 MHz) d 173.6, 172.8, 172.4, 170.8, 170.4,

164.2, 136.8, 136.2, 131.5, 130.2, 126.4. 129.5, 116.3,

116.0, 54.6, 53.6, 51.7, 42.0; IR (®lm) V_max3481, 2935,

1732, 1645, 1510 cm ¹; FABHRMS (NBA±CsI) m/z

771.1268 (M+Cs⁺, C₃₂H₃₂N₂O₈requires 771.1243).

1

5, A68B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

(m, 4H), 7.35 (m, 30H), 6.70 (m, 6H), 5.65 (m, 2H), 5.12

(s, 12H), 3.90±3.60 (m, 14H), 3.40 (m, 4H), 3.20 (m,

4H), 2.75 (m, 4H), 1.80±1.30 (m, 12H); IR (®lm) V_max

3262, 3064, 2937, 1719, 1648, 1512, 1453, 1261, 1136,

1

1025, 736, 696 cm

; FABHRMS (NBA±CsI) m/z

1711.6155 (M+Cs⁺, C₉₀H₉₈N₈O₁₈requires 1711.6053).

1

5, A79B10C4: H NMR (CDCl₃, 500 MHz) d 8.50±7.50

(m, 4H), 7.30 (m, 12H), 6.40 (br s, 4H), 5.65 (m, 2H),

5.02 (br s, 4H), 4.30 (m, 6H), 3.70 (m, 20H), 3.25 (m,

4H), 2.20 (m, 4H), 1.80±1.20 (m, 12H); IR (®lm) V_max

3293, 2948, 1718, 1654, 1543, 1508, 1454, 1208, 1129,

1

1035 cm

; FABHRMS (NBA±CsI) m/z 1379.4418

(M+Cs⁺, C₆₄H₇₈N₈O₁₈requires 1379.4488).

General procedure for the B-scan: 5, A6B23C4. A solution

of 20 (25 mg, 0.039 mmol) in DMF (1 mL) was treated

with the amine hydrochloride (25 mg, 0.098 mmol),

PyBrOP (56 mg, 0.18 mmol) and i-Pr₂NEt (55 mL,

0.3 mmol) and the mixture was stirred for 12 h at 25 ^ꢀC.

EtOAc (50 mL) was added and the mixture was washed

with 10% aqueous HCl (3Â50 mL), saturated aqueous

NaHCO₃(1Â50 mL), saturated aqueous NaCl

(1Â50 mL) and dried (Na₂SO₄). The solvent was

removed in vacuo aording 36 mg (90%) of 5,

A6B23C4 as a yellow foam: ¹H NMR (CD₃OD,

400 MHz) d 7.60±7.40 (m, 4H), 7.33 (m, 10H), 7.20 (m,

4H), 6.97 (m, 4H), 5.09 (s, 4H), 4.21±4.00 (m, 8H), 3.50±

3.35 (m, 4H), 3.28 (m, 2H), 3.15 (m, 2H), 2.80±2.69 (m,

4H), 2.39 (m, 4H), 1.75±1.40 (m, 8H); IR (®lm) V_max3420,

1652, 1558, 1508, 1456 cm ¹; FABHRMS (NBA±CsI)

N,N⁰-Bis(N,N-di(benzyloxycarbonylmethyl))benzene-1,3-

dicarboxamide (18). DibenzylN-BOC-iminodiacetale

acid (7.8 g, 20 mmol) was treated with 4 N HCl±dioxane

(100 mL) for 6 h at 25 ^ꢀC. After removal of the solvent

under a stream of N₂, the crude amine hydrochloride

was suspended in THF (170 mL) and Et₃N (22 mL,

160 mmol) was added. Isophthaloyl dichloride (2.1 g,

10 mmol) dissolved in THF (8 mL) was added and the

mixture was stirred for 4 h at 25 ^ꢀC. The reaction mix-

ture was diluted with Et₂O (200 mL) and washed with

10% aqueous HCl (2Â200 mL), 1 N aqueous NaOH

(2Â200 mL), saturated aqueous NaCl (1Â200 mL), dried

(Na₂SO₄) and concentrated. Chromatography (SiO₂,

50% EtOAc±hexanes) aorded 18 (550 mg, 77%) as a

1372

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

m/z 1149.3485 (M+Cs⁺, C₅₆H₆₂F₂N₆O₁₀requires

1149.3550).

3.24±3.09 (m, 4H), 2.80±2.70 (m, 4H), 2.39 (s, 6H), 1.80±

1.30 (m, 12H); IR (®lm) V_max3420, 2936, 1740, 1652,

1

1160 cm

; FABHRMS (NBA±CsI) m/z 1363.3624

Full characterization of selected A6B88C4 members

follow and the remaining 5, A6B49C4±A6B88C4

have also been characterized by ¹H NMR, IR, and

HRMS.

(M+Cs⁺, C₆₀H₇₂F₂N₈O₁₄S₂requires 1363.3632).

1

5, A6B22C4: H NMR (CD₃OD, 400 MHz) d 7.60±7.40

(m, 4H), 7.30 (m, 10H), 7.20 (m, 4H), 6.97 (m, 4H), 5.03

(m, 4H), 4.21±4.00 (m, 8H), 3.95 (s, 1H), 3.86 (s, 1H),

3.50±3.32 (m, 4H), 3.09 (m, 4H), 3.10 (m, 4H), 2.80±2.69

(m, 4H), 1.65±1.30 (m, 12H); IR (®lm) V_max3396,

2937, 1652, 1508, 1019 cm ¹; FABHRMS (NBA±CsI)

m/z 1267.4210 (M+Cs⁺, C₆₀H₇₂F₂N₈O₁₂requires

1267.4292).

1

5, A6B16C4: H NMR (CD₃OD, 400 MHz) d 7.55±7.35

(m, 4H), 7.30 (m, 20H), 7.20 (m, 4H), 6.97 (m, 4H), 5.15

(s, 4H), 5.00 (s, 4H), 4.50±4.28 (m, 2H), 4.21±3.92 (m,

8H), 3.41±3.32 (m, 4H), 3.10 (m, 4H), 2.80±2.69 (m,

4H), 1.96±1.50 (m, 8H); IR (®lm) V_max3421, 1652, 1508,

1253, 1020 cm ¹; FABHRMS (NBA±CsI) m/z 1447.4597

(M+Cs⁺, C₇₂H₇₆F₂N₈O₁₄requires 1447.4503).

1

5, A6B24C4: H NMR (CD₃OD, 400 MHz) d 7.60±7.40

(m, 4H), 7.31 (m, 10H), 7.22 (m, 4H), 6.97 (m, 4H), 5.03

(s, 4H), 4.47 (m, 1H), 4.36 (m, 1H), 4.21±4.00 (m, 8H),

3.70 (s, 6H), 3.45±3.35 (m, 4H), 3.13 (m, 4H), 2.80±2.69

(m, 4H), 1.95±1.45 (m, 8H); IR (®lm) V_max3292, 3057,

2934, 1652, 1540, 1507, 1219 cm ¹; FABHRMS (NBA±

CsI) m/z 1295.3869 (M+Cs⁺, C₆₀H₆₈F₂N₈O₁₄requires

1295.3877).

1

5, A6B17C4: H NMR (CD₃OD, 400 MHz) d 7.55±7.35

(m, 4H), 7.30 (m, 10H), 7.20 (m, 4H), 6.97 (m, 4H), 5.02

(s, 4H), 4.29 (m, 2H), 4.21±3.97 (m, 8H), 3.44±3.36 (m,

4H), 3.11 (m, 4H), 2.80±2.70 (m, 4H), 1.96±1.74 (m,

4H), 1.61±1.40 (m, 8H), 1.44 (s, 18H); IR (®lm) V_max

3421, 1841, 1653, 1406, 1018 cm ¹; FABHRMS (NBA±

CsI) m/z 1407.5222 (M+Cs⁺, C₆₈H₈₄F₂N₈O₁₄requires

1407.5129).

1

5, A6B25C4: H NMR (CD₃OD, 400 MHz) d 7.60±7.40

(m, 4H), 7.22 (m, 4H), 6.97 (m, 4H), 4.22±4.00 (m, 8H),

3.65 (s, 6H), 3.50±3.35 (m, 4H), 3.26 (m, 2H), 3.17 (m,

2H), 2.80±2.69 (m, 4H), 2.42 (m, 2H), 2.29 (m, 2H), 1.84

(m, 2H), 1.73, (m, 2H); IR (®lm) V_max3421, 1734, 1652,

1508, 1220 cm ¹; FABHRMS (NBA±CsI) m/z 969.2646

(M+Cs⁺, C₄₂H₅₀F₂N₆O₁₀requires 969.2611).

1

5, A6B18C4: H NMR (CD₃OD, 400 MHz) d 7.55±7.35

(m, 4H), 7.22 (m, 4H), 6.98 (m, 4H), 4.56 (m, 1H), 4.35

(m, 1H), 4.21±3.00 (m, 8H), 3.73 (s, 6H), 3.41±3.39 (m,

4H), 3.03 (m, 4H), 2.80±2.69 (m, 4H), 1.96±1.74 (m,

4H), 1.61±1.40 (m, 8H), 1.41 (s, 18H); IR (®lm) V_max

3411, 1734, 1652, 1508, 1019 cm ¹; FABHRMS (NBA±

CsI) m/z 1255.4572 (M+Cs⁺, C₅₆H₇₆F₂N₈O₁₄requires

1255.4503).

1

5, A6B26C4: H NMR (CD₃OD, 400 MHz) d 7.60±7.40

(m, 4H), 7.22 (m, 4H), 6.97 (m, 4H), 4.22±4.00 (m, 8H),

3.63 (s, 6H), 3.50±3.35 (m, 4H), 3.25 (m, 2H), 3.13 (m,

2H), 2.80±2.69 (m, 4H), 2.32 (m, 4H), 1.60±1.28 (m,

1

5, A6B19C4: H NMR (CD₃OD, 400 MHz) d 7.55±7.35

(m, 4H), 7.31 (m, 10H), 7.20 (m, 4H), 6.97 (m, 4H), 5.06

(s, 4H), 4.14 (m, 2H), 4.2±3.98 (m, 8H), 3.44±3.37 (m,

4H), 3.21 (m, 2H), 3.09 (m, 2H), 2.80±2.69 (m, 4H),

12H); IR (®lm) V_max3267, 3072, 2937, 1734, 1652,

1

1509 cm

; FABHRMS (NBA±CsI) m/z 1025.2286

(M+Cs⁺, C₄₆H₅₈F₂N₆O₁₀requires 1025.3234).

1.85±1.40 (m, 12H); IR (®lm) V_max3420, 1652, 1508,

1

1418, 1016 cm

1293.4121

1293.4197).

;

FABHRMS (NBA±CsI) m/z

requires

5, A6B27C4: H NMR (CD₃OD, 400 MHz) d 7.60±7.40

(M+Cs⁺,

C₆₀H₇₀F₂N₁₀O₁₂

(m, 4H), 7.22 (m, 4H), 6.97 (m, 4H), 4.20±4.00 (m, 8H),

4.14 (q, 4H, J=7.2 Hz), 3.90±3.70 (m, 2H), 3.50±3.35

(m, 4H), 2.96 (m, 4H), 2.80±2.69 (m, 4H), 1.90±1.75 (m,

1

5, A6B20C4: H NMR (CD₃OD, 400 MHz) d 7.55±7.35

(m, 4H), 7.30 (m, 20H), 7.15 (m, 4H), 6.94 (m, 4H), 5.16

(m, 4H), 5.00 (br s, 4H), 4.49 (m, 1H), 4.35 (m, 1H),

4.15±3.92 (m, 8H), 3.41±3.30 (m, 4H), 3.05 (m, 4H),

2H), 1.48±1.26 (m, 2H), 1.25 (t, 6H, J=7.2 Hz); IR

1

(®lm) V_max3421, 1652, 1437, 1019, 953 cm

;

FABHRMS (NBA±CsI) m/z 1079.3402 (M+Cs⁺,

C₄₈H₆₀F₂N₈O₁₀requires 1079.3455).

2.80±2.63 (m, 4H), 1.75 (m, 4H), 1.51±1.26 (m, 8H); IR

1

(®lm) V_max3421, 1653, 1406, 1018, 953 cm

;

5, A6B28C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

FABHRMS (NBA±CsI) m/z 1475.4721 (M+Cs⁺,

C₇₄H₈₀F₂N₈O₁₄requires 1475.4816).

(m, 4H), 7.28 (m, 4H), 7.19 (m, 4H), 6.96 (m, 10H), 4.53

(s, 4H), 4. 48 (m, 2H), 4.21±3.92 (m, 8H), 3.70 (s, 6H),

3.41±3.32 (m, 4H), 3.24±3.09 (m, 4H), 2.80±2.69 (m,

4H), 1.96±1.74 (m, 4H), 1.61±1.40 (m, 8H); IR (®lm)

V_max3421, 2920, 1652, 1437, 1019 cm ¹; FABHRMS

(NBA±CsI) m/z 1323.4282 (M+Cs⁺, C₆₂H₇₂F₂N₈O₁₄

requires 1323.4190).

5, A6B21C4: ¹H NMR (CD₃OD, 400 MHz) d 7.68 (d,

4H, J=8.2 Hz), 7.60±7.40 (m, 4H), 7.32 (d, 4H,

J=8.2 Hz), 7.19 (m, 4H), 6.97 (m, 4H), 4.16±3.95 (m,

8H), 3.82 (m, 2H), 3.45±3.35 (m, 4H), 3.37, (m, 6H),

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1373

1

5, A6B29C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 4.24 (m, 2H), 4.21±3.92 (m, 8H), 3.67 (s, 6H),

3.41±3.32 (m, 4H), 3.24±3.09 (m, 4H), 2.80±2.69 (m,

4H), 1.96±1.40 (m, 12H); IR (®lm) V_max1652, 1437,

1318, 1019, 953 cm ¹; FABHRMS (NBA±CsI) m/z

(m, 4H), 7.30 (m, 4H), 7.19 (m, 4H), 7.06±6.77 (m, 10H),

4.21 (m, 2H), 4.12±3.92 (m, 8H), 3.71 (s, 6H), 3.41±3.32

(m, 4H), 3.24±3.09 (m, 4H), 2.80±2.69 (m, 4H),

1.96±1.74 (m, 4H), 1.61±1.40 (m, 8H); IR (®lm) V_max

1653, 1437, 1406, 1019 cm ¹; FABHRMS (NBA±CsI)

m/z 1295.3930 (M+Cs⁺, C₆₀H₆₈F₂N₈O₁₄requires

1295.3877).

1321.4564

1321.4510).

(M+Cs⁺,

C₆₂H₇₄F₂N₁₀O₁₂

requires

1

5, A6B36C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.22 (m, 4H), 6.96 (m, 4H), 4.33 (m, 2H), 4.21±

3.92 (m, 8H), 3.67 (s, 6H), 3.41±3.32 (m, 4H), 3.24±3.09

(m, 4H), 2.80±2.69 (m, 4H), 1.96±1.74 (m, 4H), 1.80 (m,

10H), 1.61±1.40 (m, 8H), 1.34 (m, 12H); IR (®lm) V_max

3406, 1654, 1437, 1407, 1020 cm ¹; FABHRMS (NBA±

CsI) m/z 1275.4999 (M+Cs⁺, C₆₀H₈₀F₂N₈O₁₂requires

1275.4918).

1

5, A6B30C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.23 (m, 4H), 6.98 (m, 4H), 4.3 (m, 2H), 4.21±

3.92 (m, 8H), 3.69 (s, 6H), 3.60 (s, 6H), 3.41±3.32 (m,

4H), 3.24±3.09 (m, 4H), 2.80±2.69 (m, 4H), 1.96±1.74

(m, 4H), 1.61±1.40 (m, 8H); IR (®lm) V_max3410, 1652,

1437, 1017, 953 cm ¹; FABHRMS (NBA±CsI) m/z

1171.3622

1171.3564).

(M+Cs⁺,

C₅₀H₆₄F₂N₈O₁₄

requires

1

5, A6B37C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.38 (s, 10H), 7.22 (m, 4H), 6.96 (m, 4H), 5.15

(m, 4H), 4.91 (m, 2H), 4.11±4.06 (m, 4H), 3.97 (br s,

4H), 3.71 (s, 6H), 3.41±3.32 (m, 4H), 3.28±3.09 (m, 4H),

1

5, A6B31C4: H NMR (CD₃OD, 400 MHz) d 7.82 (m,

4H), 7.50±7.45 (m, 4H), 7.44 (m, 6H), 7.19 (m, 4H), 6.96

(m, 4H), 4.56 (m, 2H), 4.21±3.92 (m, 8H), 3.70 (s, 6H),

3.41±3.32 (m, 4H), 3.24±3.09 (m, 4H), 2.80±2.69 (m,

4H), 1.96±1.74 (m, 4H), 1.61±1.40 (m, 8H); IR (®lm)

V_max3421, 1652, 1418, 1017, 952 cm ¹; FABHRMS

(NBA±CsI) m/z 1263.4045 (M+Cs⁺, C₆₀H₆₈F₂N₈O₁₂

requires 1263.3979).

2.80±2.69 (m, 4H), 1.84 (m, 4H), 1.61±1.36 (m, 8H); IR

1

(®lm) V_max3266, 3071, 1748, 1652, 1509, 1221 cm

;

FABHRMS (NBA±CsI) m/z 1325.3940 (M+Cs⁺,

C₆₂H₇₀F₂N₆O₁₆requires 1325.3871).

1

5, A6B38C4: H NMR (CD₃OD, 400 MHz) d 8.02 (m,

4H), 7.50±7.45 (m, 4H), 7.47 (m, 6H), 7.22 (m, 4H), 6.96

(m, 4H), 5.19 (m, 2H), 4.11±3.97 (m, 8H), 3.71 (s, 6H),

3.41±3.32 (m, 4H), 3.28±3.09 (m, 4H), 2.80±2.69 (m,

4H), 1.99 (m, 4H), 1.61±1.36 (m, 8H); IR (®lm) V_max

3648, 1717, 1653, 1508 cm ¹; FABHRMS (NBA±CsI)

m/z 1265.3659 (M+Cs⁺, C₆₀H₆₆F₂N₆O₁₄requires

1265.3733).

1

5, A6B32C4: H NMR (CD₃OD, 400 MHz) d 7.67 (m,

2H), 7.56 (m, 2H), 7.50±7.45 (m, 4H), 7.44 (m, 2H), 7.19

(m, 4H), 7.16 (m, 2H), 6.96 (m, 4H), 4.56 (m, 2H), 4.21±

3.92 (m, 8H), 3.70, (s, 6H), 3.41±3.32 (m, 4H), 3.24±3.09

(m, 4H), 2.80±2.69 (m, 4H), 1.96±1.74 (m, 4H), 1.61±

1.40 (m, 8H); IR (®lm) V_max3420, 1684, 1653, 1540,

1

1017 cm

; FABHRMS (NBA±CsI) m/z 1299.3879

1

(M+Cs⁺, C₆₀H₆₆F₄N₈O₁₂requires 1299.3791).

5, A6B39C4: H NMR (CD₃OD, 400 MHz) d 8.08 (m,

4H), 7.50±7.45 (m, 4H), 7.22 (m, 4H), 7.19 (m, 4H), 6.96

(m, 4H), 5.19 (m, 2H), 4.11±3.97 (m, 8H), 3.71 (s, 6H),

3.41±3.32 (m, 4H), 3.28±3.09 (m, 4H), 2.80±2.69 (m,

4H), 1.99 (m, 4H), 1.61±1.36 (m, 8H); IR (®lm) V_max

3261, 3070, 2937, 1718, 1653, 1508 cm ¹; FABHRMS

(NBA±CsI) m/z 1301.3539 (M+Cs⁺, C₆₀H₆₄F₄N₆O₁₄

requires 1301.3471).

1

5, A6B33C4: H NMR (CD₃OD, 400 MHz) d 7.89 (m,

4H), 7.50±7.45 (m, 4H), 7.19 (m, 4H), 7.16 (m, 4H), 6.96

(m, 4H), 4.56 (m, 2H), 4.21±3.92 (m, 8H), 3.70 (s, 6H),

3.41±3.32 (m, 4H), 3.24±3.09 (m, 4H), 2.80±2.69 (m,

4H), 1.96±1.74 (m, 4H), 1.61±1.40 (m, 8H); IR (®lm)

V_max3419, 1652, 1437, 1019, 953 cm ¹; FABHRMS

(NBA±NaI) m/z 1189.4635 (M+Na⁺, C₆₀H₆₆F₄N₈O₁₂

requires 1189.4634).

1

5, A6B40C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.33 (m, 4H), 7.20 (m, 4H), 6.95 (m, 4H), 5.02

(m, 2H), 4.11±3.97 (m, 8H), 3.82 (m, 18H), 3.71 (s, 6H),

3.41±3.32 (m, 4H), 3.28±3.09 (m, 4H), 2.80±2.69 (m,

1

5, A6B34C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.19 (m, 4H), 7.17 (m, 4H), 6.96 (m, 4H), 4.56

(dd, 2H, J=9.2, 5.2 Hz), 4.21±3.92 (m, 8H), 3.84 (s,

12H), 3.78 (s, 6H), 3.70, (s, 6H), 3.41±3.32 (m, 4H),

3.24±3.09 (m, 4H), 2.80±2.69 (m, 4H), 1.96±1.74 (m,

4H), 1.61±1.40 (m, 8H); IR (®lm) V_max3422, 1654, 1407,

1018, 953 cm ¹; FABHRMS (NBA±CsI) m/z 1444.5000

(M+Cs⁺, C₆₆H₈₀F₂N₈O₁₈requires 1444.4613).

4H), 1.99 (m, 4H), 1.61±1.36 (m, 8H); IR (®lm) V_max

1

3267, 2942, 1716, 1652, 1506, 1220, 1127 cm

;

FABHRMS (NBA±CsI) m/z 1445.4386 (M+Cs⁺,

C₆₆H₇₈F₂N₆O₂₀requires 1445.4293).

1

5, A6B41C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.31 (m, 6H), 7.22 (m, 4H), 7.19 (m, 4H), 6.94

(m, 4H), 5.19 (m, 4H), 4.91 (m, 2H), 4.11±4.06 (m, 4H),

3.97 (br s, 4H), 3.71 (s, 6H), 3.41±3.32 (m, 4H), 3.28±3.09

1

5, A6B35C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.26 (m, 10H), 7.19 (m, 4H), 6.96 (m, 4H), 4.26

1374

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

(m, 4H), 2.80±2.69 (m, 4H), 1.84 (m, 4H), 1.61±1.36 (m,

8H); IR (®lm) V_max3266, 3071, 1748, 1652, 1509,

(m, 8H), 2.80±2.69 (m, 4H), 1.66±1.28 (m, 32H); IR

1

(®lm) V_max3286, 3071, 2928, 1652, 1510, 1251 cm ;

FABHRMS (NBA±CsI) m/z 1347.5559 (M+Cs⁺,

C₆₈H₈₈F₂N₈O₁₀requires 1347.5646).

1

1221 cm

;

FABHRMS (NBA±CsI) m/z 1325.3940

(M+Cs⁺, C₆₂H₇₀F₂N₆O₁₆requires 1325.3871).

1

5, A6B42C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.31 (m, 10H), 7.18 (m, 4H), 6.96 (m, 4H), 5.04

5, A6B89C4: H NMR (CD₃OD, 400 MHz) d 7.55±7.45

(m, 4H), 7.30 (m, 20H), 7.15 (m, 4H), 6.94 (m, 4H), 5.16

(m, 4H), 5.00 (br s, 4H), 4.50±4.28 (m, 2H), 4.15±3.92

(m, 8H), 3.41±3.30 (m, 4H), 3.05 (m, 4H), 2.80±2.63 (m,

4H), 1.75 (m, 4H), 1.51±1.26 (m, 8H); IR (®lm) V_max

3421, 1653, 1540, 1508, 1252 cm ¹; FABHRMS (NBA±

CsI) m/z 1475.4723 (M+Cs⁺, C₇₄H₈₀F₂N₈O₁₄requires

1475.4816).

(s, 4H), 4.21±3.92 (m, 8H), 3.41±3.32 (m, 4H), 3.24±3.09

(m, 8H), 2.80±2.69 (m, 4H), 1.66±1.58 (m, 4H); IR (®lm)

V_max3284, 3069, 2937, 1652, 1509, 1254 cm

FABHRMS (NBA±CsI) m/z 1151.3510 (M+Cs⁺,

C₅₄H₆₀F₂N₈O₁₀requires 1151.3455).

1

;

1

5, A6B43C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.31 (m, 10H), 7.18 (m, 4H), 6.96 (m, 4H), 5.04

(s, 4H), 4.21±3.92 (m, 8H), 3.41±3.32 (m, 4H), 3.24±3.09

(m, 8H), 2.80±2.69 (m, 4H), 1.55 (br s, 4H), 1.44 (br s,

5, A6B90C4: ¹H NMR (CD₃OD, 400 MHz) d 8.10 (d,

4H, J=6.8 Hz), 7.60±7.45 (m, 4H), 7.30 (m, 10H), 7.17

(m, 4H), 6.94 (m, 4H), 6.87 (d, 4H, J=6.8 Hz), 5.08 (s,

4H), 4.50±4.28 (m, 2H),4.15±3.92 (m, 8H), 3.41±3.30 (m,

4H), 3.25±3.16 (m, 4H), 2.80±2.63 (m, 4H), 1.96±1.74 (m,

4H); IR (®lm) V_max3280, 3068, 2936, 1652, 1509,

1

1254 cm

; FABHRMS (NBA±CsI) m/z 1179.3702

(M+Cs⁺C₅₆H₆₄F₂N₈O₁₀requires 1179.3768).

4H), 1.61±1.40 (m, 8H); IR (®lm) V_max3422, 1652, 1509,

1

1292 cm

; FABHRMS (NBA±CsI) m/z 1475.4723

1

5, A6B44C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.31 (m, 10H), 7.18 (m, 4H), 6.96 (m, 4H), 5.04

(M+Cs⁺, C₇₂H₇₄F₂N₁₀O₁₈requires 1475.4816).

1

(s, 4H), 4.21±3.92 (m, 8H), 3.41±3.32 (m, 4H), 3.22±3.08

(m, 8H), 2.80±2.69 (m, 4H), 1.66±1.28 (m, 12H); IR

5, A6B91C4: H NMR (CD₃OD, 400 MHz) d 7.60±7.45

(m, 4H), 7.30 (m, 10H), 7.20 (m, 4H), 6.97 (m, 4H), 5.02

(s, 4H), 4.50±4.28 (m, 2H), 4.21±3.92 (m, 8H), 3.69, (s,

6H), 3.41±3.32 (m, 4H), 3.09 (m, 4H), 2.80±2.69 (m,

4H), 1.96±1.74 (m, 4H), 1.61±1.40 (m, 8H); IR (®lm)

V_max3422, 1652, 1508, 1219 cm ¹; FABHRMS (NBA±

CsI) m/z 1323.4112 (M+Cs⁺, C₆₂H₇₂F₂N₈O₁₄requires

1323.4190).

1

(®lm) V_max3279, 3070, 2936, 1652, 1509, 1248 cm

;

FABHRMS (NBA±CsI) m/z 1207.4012 (M+Cs⁺,

C₅₈H₆₈F₂N₈O₁₀requires 1207.4081).

1

5, A6B45C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.31 (m, 10H), 7.18 (m, 4H), 6.96 (m, 4H), 5.04

(s, 4H), 4.21±3.92 (m, 8H), 3.41±3.32 (m, 4H), 3.22±3.08

(m, 8H), 2.80±2.69 (m, 4H), 1.66±1.28 (m, 16H); IR

1

5, A6B92C4: H NMR (CD₃OD, 400 MHz) d 7.60±7.45

1

(®lm) V_max3278, 2936, 1652, 1508, 1254 cm

;

(m, 4H), 7.30 (m, 10H), 7.20 (m, 4H), 6.97 (m, 4H), 5.02

(s, 4H), 4.50±4.28 (m, 2H), 4.21±3.92 (m, 8H), 3.69, (s,

6H), 3.41±3.32 (m, 4H), 3.09 (m, 4H), 2.80±2.69 (m,

4H), 1.96±1.74 (m, 4H), 1.61±1.40 (m, 8H); IR (®lm)

V_max3421, 1652, 1508, 1456, 1221 cm ¹; FABHRMS

(NBA±CsI) m/z 1323.4269 (M+Cs⁺, C₆₂H₇₂F₂N₈O₁₄

requires 1323.4190).

FABHRMS (NBA±CsI) m/z 1235.4470 (M+Cs⁺,

C₆₀H₇₂F₂N₈O₁₀requires 1235.4394).

1

5, A6B46C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.31 (m, 10H), 7.18 (m, 4H), 6.96 (m, 4H), 5.04

(s, 4H), 4.21±3.92 (m, 8H), 3.41±3.32 (m, 4H), 3.22±3.08

(m, 8H), 2.80±2.69 (m, 4H), 1.66±1.28 (m, 20H); IR

1

(®lm) V_max3285, 3071, 2933, 1652, 1509, 1248 cm

;

Dimethyl 5-((2-((tert-butyloxy)carbonyl)amino)ethoxy)-

benzene-1,3-dicarboxylate (21). A solution of N-BOC-2-

bromoethylamine (986 mg, 4.4 mmol) in butanone

(17 mL) was treated with dimethyl 5-hydroxyiso-

phthalate (840 mg, 4.0 mmol), NaI (660 mg, 4.4 mmol)

and Cs₂CO₃(1.44 g, 4.4 mmol), and the resulting sus-

pension was stirred vigorously at 70 ^ꢀC for 8 h. The

cooled reaction mixture was diluted with CH₂Cl₂

(200 mL) and washed with saturated aqueous NaCl

(2Â100 mL), dried (Na₂SO₄) and concentrated. Flash

chromatography (SiO₂, 5% EtOAc±CH₂Cl₂) provided

FABHRMS (NBA±CsI) m/z 1263.4632 (M+Cs⁺,

C₆₂H₇₆F₂N₈O₁₀requires 1263.4707).

1

5, A6B47C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.31 (m, 10H), 7.18 (m, 4H), 6.96 (m, 4H), 5.04

(s, 4H), 4.21±3.92 (m, 8H), 3.41±3.32 (m, 4H), 3.22±3.08

(m, 8H), 2.80±2.69 (m, 4H), 1.66±1.28 (m, 24H); IR

1

(®lm) V_max3284, 3071, 2931, 1652, 1509, 1252 cm

;

FABHRMS (NBA±CsI) m/z 1291.5095 (M+Cs⁺,

requires C₆₄H₈₀F₂N₈O₁₀1291.5020).

1

21 (1.13 g, 80%) as a white amorphous solid: H NMR

(CDCl₃, 400 MHz) d 7.97 (s, 1H), 7.45 (s, 2H), 3.99 (m,

1

5, A6B48C4: H NMR (CD₃OD, 400 MHz) d 7.50±7.45

(m, 4H), 7.31 (m, 10H), 7.18 (m, 4H), 6.96 (m, 4H), 5.04

(s, 4H), 4.21±3.92 (m, 8H), 3.41±3.32 (m, 4H), 3.22±3.08

2H), 3.91 (t, 2H, J=5 Hz), 3.73 (s, 6H), 1.26 (s, 9H); ¹³

C

NMR (CDCl₃, 100 MHz) d 165.6, 158.4, 155.8, 131.4,

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

1375

122.9, 119.4, 79.1, 67.5, 52.2, 39.8, 28.2; IR (®lm) V_max

1

4H), 5.08 (s, 4H), 4.37±4.21 (m, 4H), 4.17±4.06 (m,

10H), 3.73 (s, 6H), 3.67 (s, 6H), 3.40±3.29 (m, 4H), 3.27±

3.12 (m, 4H), 1.80±1.45 (m, 12H), 1.40 (s, 9H); IR (®lm)

V_max3260, 2940, 1651, 1512, 1250 cm ¹; FABHRMS

(NBA±CsI) m/z 1478.5206 (M+Cs⁺, C₆₉H₈₇N₉O₁₉

requires 1478.5173).

3387, 2953, 1732, 1595, 1518, 1434, 1340, 1248 cm

;

FABHRMS (NBA±NaI) m/z 354.1564 (M+H⁺,

C₁₇H₂₃NO₇requires 354.1553).

5-(2-(((tert-Butyloxy)carbonyl)amino)ethoxy)benzene-1,3-

dicarboxylic acid (22). A solution of 21 (780 mg,

2.2 mmol) in THF±CH₃OH±H₂O (15 mL, 3:1:1) was

23, A6B10: ¹H NMR (CD₃OD, 400 MHz) d 7.31 (m,

11H), 7.24±7.12 (m, 4H), 7.06 (m, 2H), 6.98 (m, 4H),

5.05 (s, 4H), 4.18±3.92 (m, 10H), 3.67 (s, 6H), 3.46 (m,

4H), 3.38 (m, 4H), 3.26±3.12 (m, 4H), 3.28±3.07 (m,

4H), 1.83±1.44 (m, 12H), 1.41 (s, 9H); IR (®lm) V_max

3363, 2970, 1717, 1537, 1245 cm ¹; FABHRMS (NBA±

CsI) m/z 1482.5184 (M+Cs⁺, C₆₉H₈₅N₉O₁₇requires

1482.5086).

.

treated with LiOH H₂O (464 mg, 11.1 mmol) and stirred

for 1.5 h at 25 ^ꢀC. The solution was concentrated to a

volume of 3 mL and diluted with 35 mL H₂O. Con-

centrated aqueous HCl (1.0 mL) was slowly added while

stirring at 0 ^ꢀC. The precipitate that formed was ®ltered,

washed with 50 mL H₂O, and dried in vacuo to provide

22 (550 mg, 77%) as a white powder: ¹H NMR (DMSO-

d₆, 400 MHz) d 13.32 (s, 2H), 8.09 (s, 1H), 7.65 (s, 2H),

7.06 (t, 1H, J=5.0 Hz), 4.09 (t, 2H, J=5.0 Hz), 3.33 (m,

2H), 1.38 (s, 9H); ¹³C NMR (DMSO-d₆, 100 MHz) d

166.4, 158.7, 155.7, 132.6, 122.4, 119.3, 77.8, 67.2, 39.8,

23, A7B10: ¹H NMR (CD₃OD, 400 MHz) d 7.30 (m,

21H), 7.08 (m, 2H), 5.08, (s, 8H), 4.20±3.90 (m, 12H),

3.67 (s, 12H), 3,37 (m, 4H), 3.25±3.06 (m, 8H), 1.83±1.45

(m, 12H), 1.41 (s, 9H); IR (®lm) V_max3328, 2951,

1700, 1653, 1540 cm ¹; FABHRMS (NBA±CsI) m/z

28.3; IR (®lm) V_max2978, 2361, 1699, 1507, 1266,

1

1168 cm

; FABHRMS (NBA±NaI) m/z 348.1076

(M+Na⁺, C₁₅H₁₉NO₇requires 348.1059).

1792.6494

1792.6650).

(M+Cs⁺,

C₈₃H₁₀₉N₁₁O₂₅

requires

General procedure for the synthesis of 23, A6B23. The

N-BOC-iminodiacetic acid diamide 4, A6B23 (345 mg,

0.66 mmol) was treated with 4 N HCl±dioxane (5 mL)

and allowed to stand at 25 ^ꢀC for 2 h. The solvent was

removed under a stream of N₂, and the resulting residue

was treated with a solution of 22 (97.5 mg, 0.3 mmol) in

DMF (6 mL), followed by PyBrOP (420 mg, 0.9 mmol),

and i-Pr₂NEt (420 mL, 2.40 mmol) and the mixture was

stirred for 12 h at 25 ^ꢀC. The solution was diluted with

EtOAc (100 mL) and washed with 10% aqueous HCl

(3Â75 mL), saturated aqueous NaHCO₃(1Â75 mL),

and saturated aqueous NaCl (1Â75 mL). Drying

(Na₂SO₄), and evaporation provided 210 mg (88%) of

23, A6B23 as a yellow foam: ¹H NMR (CD₃OD,

400 MHz) d 7.36±7.28 (m, 11H), 7.18 (m, 4H), 7.08 (m,

2H), 6.96 (m, 4H), 5.07 (s, 4H), 4.12±3.90 (m, 8H), 3.43

(m, 4H), 3.36 (m, 4H), 3.26±3.10 (m, 4H), 2.84 ±2.69 (m,

4H), 2.37 (m, 4H), 1.70±1.42 (m, 8H), 1.40 (s, 9H); IR

23, A8B10: ¹H NMR (CD₃OD, 400 MHz) d 7.33 (m,

11H), 7.13±7.04 (m, 2H), 5.06 (s, 4H), 4.42 (m, 2H), 4.30

(m, 2H), 4.19±4.08 (m, 4H), 4.02±3.88 (m, 10H), 3.70 (s,

6H), 3.59 (m, 4H), 3.43 (m, 2H), 3.26±3.12 (m, 4H),

1.80±1.45 (m, 20H), 1.43 (s, 9H); IR (®lm) V_max3438,

2953, 1645, 1456, 1240 cm ¹; FABHRMS (NBA±CsI)

m/z 1490.5487 (M+Cs⁺, C₆₇H₉₁N₉O₂₁requires

1490.5384).

1

23, A12B10: H NMR (CD₃OD, 400 MHz) d 7.30 (m,

11H), 7.19 (m, 2H), 7.08 (m, 2H), 6.88 (m, 4H), 5.04 (s,

4H), 4.18±3.90 (m, 10H), 3.67 (s, 6H), 3.49 (m, 4H), 3.42

(m, 4H), 3.26±3.10 (m, 4H), 3.01 (m, 4H), 1.80±1.46 (m,

12H), 1.41 (s, 9H); IR (®lm) V_max3316, 2938, 1652, 1540,

1

1252 cm

; FABHRMS (NBA±CsI) m/z 1458.4503

(M+Cs⁺, C₆₅H₈₃N₉O₁₇S₂requires 1458.4403).

(®lm) V_max3423, 3077, 2941, 1649, 1507, 1223,

1

General procedure for 24, A6B23C4. A sample of 23

(A6B23, 55 mg, 0.044 mmol) was treated with 4 N

HCl±dioxane (1 mL) and this mixture was allowed to

stand for 3 h before solvent and excess acid were

removed under a stream of N₂. The resulting residue

was dissolved in DMF (300 mL) and i-Pr₂NEt (20 mL,

0.12 mmol) was added. After dissolution, 100 mL of

diglycolic acid stock solution (prepared by dissolving

2 mmol of diglycolic acid in 10 mL DMF) was added

followed by PyBrOP (28 mg, 0.06 mmol). After stirring

for 12 h at 25 ^ꢀC the reaction mixture was diluted with

EtOAc (50 mL) and washed with 10% aqueous HCl

(3Â50 mL), saturated aqueous NaCl (1Â50 mL), satu-

rated aqueous NaHCO₃(1Â50 mL), and saturated

aqueous NaCl (1Â50 mL). Drying (Na₂SO₄), and

1161 cm

; FABHRMS (NBA±NaI) m/z 1198.5359

(M+Na⁺, C₆₃H₇₅F₂N₇O₁₃requires 1198.5288).

23, A2B10: ¹H NMR (CD₃OD, 400 MHz) d 7.29 (m,

11H), 7.12 (m, 4H), 7.07 (m, 2H), 6.78 (m, 4H), 5.06 (s,

4H), 4.19±3.90 (m, 10H), 3.71 (s, 6H), 3.65 (s, 6H), 3.40

(m, 4H), 3.35 (m, 4H), 3.26±3.12 (m, 4H), 2.72 (m, 4H),

1.84±1.48 (m, 12H), 1.40 (s, 9H); IR (®lm) V_max3455,

2951, 2467, 1646, 1430 cm ¹; FABHRMS (NBA±CsI)

m/z 1506.5522 (M+Cs⁺, C₇₁H₉₁N₉O₁₉requires

1506.5486).

23, A5B10: ¹H NMR (CD₃OD, 400 MHz) d 7.31 (m,

11H), 7.24 (m, 4H), 7.16 (m, 4H), 7.11 (m, 2H), 6.84 (m,

1376

D. L. Boger et al./Bioorg. Med. Chem. 6 (1998) 1347±1378

evaporation provided 24, A6B23C4 (47 mg, 88%) as a

yellow foam: ¹H NMR (CD₃OD, 400 MHz) d 7.50±7.33

(m, 4H), 7.32±7.24 (m, 14H), 7.24±7.05 (m, 20H), 6.97±

6.91 (m, 8H), 5.07 (s, 8H), 4.14±3.94 (m, 20H), 3.59 (m,

4H), 3.45±3.30 (m, 8H), 3.23±3.14 (m, 8H), 2.75 (m,

8H), 2.38 (m, 8H), 1.68±1.40 (m, 16H); IR (®lm) V_max

3251, 2926, 1722, 1638, 1458, 1223 cm ¹; ESMS pos:

M+H⁺2282; neg: M H⁺2280.

24, A6B23C45: ¹H NMR (CD₃OD, 400 MHz) d 7.33±

7.25 (m, 14H), 7.22±7.13 (m, 8H), 7.08±7.01 (m, 6H),

6.97±6.91 (m, 8H), 5.08 (s, 8H), 4.14±3.94 (m, 24H),

3.72±3.52 (m, 12H), 3.46±3.30 (m, 8H), 3.23±3.14 (m,

8H), 2.75 (m, 8H), 2.38 (m, 8H), 1.68±1.40 (m, 16H); IR

(®lm) V_max2930, 1733, 1646, 1466, 1219 cm ¹; ESMS

pos: M+H⁺2339; neg: M H⁺2337.

24, A6B23C50. ¹H NMR (CD₃OD, 400 MHz) d 7.32±

7.24 (m, 14H), 7.24±7.05 (m, 20H), 6.97±6.91 (m, 8H),

5.07 (s, 8H), 4.14±3.94 (m, 20H), 3.59 (m, 4H), 3.46 (m,

4H), 3.42±3.30 (m, 8H), 3.23±3.08 (m, 12H), 2.78 (m,

24, A6B23C2: ¹H NMR (CD₃OD, 400 MHz) d 7.34±7.24

(m, 14H), 7.22±7.03 (m, 20H), 6.97±6.91 (m, 8H), 6.85

(m, 2H), 5.07 (s, 8H), 4.14±3.94 (m, 20H), 3.61 (m, 4H),

3.45±3.30 (m, 8H), 3.23±3.14 (m, 8H), 2.75 (m, 8H), 2.38

(m, 8H), 1.68±1.40 (m, 16H); IR (®lm) V_max3249, 2940,

1718, 1636, 1507, 1219 cm ¹; ESMS pos: M+H⁺2233;

neg: M H⁺2232.

4H), 2.73 (m, 8H), 2.38 (m, 8H), 1.68±1.40 (m, 16H); IR

1

(®lm) V_max3270, 2940, 1733, 1656, 1507, 1224 cm

ESMS pos: M+H⁺2401; neg: M H⁺2399.

;

24, A6B23C51: ¹H NMR (CD₃OD, 400 MHz) d 7.32±

7.24 (m, 14H), 7.24±7.05 (m, 20H), 6.97±6.91 (m, 12H),

5.07 (s, 8H), 4.14±3.94 (m, 20H), 3.69 (m, 4H), 3.47 (m,

4H), 3.48 (m, 4H), 3.43±3.30 (m, 8H), 3.23±3.14 (m,

24, A6B23C5: ¹H NMR (CD₃OD, 400 MHz) d 7.32±

7.24 (m, 18H), 7.24±7.02 (m, 20H), 6.96±6.91 (m, 8H),

5.05 (s, 8H), 4.14±3.94 (m, 20H), 3.58 (m, 4H), 3.45±3.30

(m, 8H), 3.23±3.13 (m, 8H), 2.75 (m, 8H), 2.38 (m, 8H),

1.68±1.40 (m, 16H); IR (®lm) V_max3274, 2926, 1728,

1633, 1458, 1223 cm ¹; ESMS pos: M+Na⁺2305; neg:

M+Cl 2317.

12H), 2.75 (m, 8H), 2.38 (m, 8H), 1.68±1.40 (m, 16H);

1

IR (®lm) V_max2930, 1713, 1631, 1466, 1218 cm

ESMS pos: M+H⁺2239; neg: M H⁺2237.

;

24, A6B23C16: ¹H NMR (CD₃OD, 400 MHz) d 7.32±

7.24 (m, 14H), 7.24±7.05 (m, 20H), 6.97±6.91 (m, 10H),

6.24 (m, 2H), 5.07 (s, 8H), 4.14±3.94 (m, 20H), 3.59 (m,

4H), 3.45±3.30 (m, 8H), 3.23±3.14 (m, 8H), 2.75 (m,

8H), 2.38 (m, 8H), 1.68±1.40 (m, 16H); IR (®lm) V_max

3251, 2926, 1727, 1638, 1453, 1223 cm ¹; ESMS pos:

M+Na⁺2281; neg: M+Cl 2293.

Acknowledgements

The authors gratefully acknowledge the ®nancial sup-

port of the National Institutes of Health (CA78045),

Johnson and Johnson, The Skaggs Institute for Chemi-

cal Biology, and the award of a National Defense Sci-

ence and Engineering predoctoral fellowship (J.G.).

24, A6B23C19: ¹H NMR (CD₃OD, 400 MHz) d 7.83

(m, 4H), 7.42 (m, 4H), 7.34±7.22 (m, 14H), 7.24±7.05

(m, 20H), 6.97±6.88 (m, 8H), 5.07 (s, 8H), 4.14±3.94 (m,

20H), 3.59 (m, 4H), 3.45±3.30 (m, 8H), 3.23±3.14 (m,

8H), 2.75 (m, 8H), 2.38 (m, 8H), 1.68±1.40 (m, 16H); IR

(®lm) V_max2940, 1631, 1502, 1464, 1217 cm ¹; ESMS

pos: M+H⁺2509; neg: M H⁺2507.

References and Notes

1. Heldin, C.-H. Cell 1995, 80, 213. Wells, J. A. Curr. Opin.

Cell Biol. 1994, 6, 163.

2. Hinterding, K.; Alonso-Diaz, D.; Waldmann, H. Angew.

Chem., Int. Ed. Engl. 1998, 37, 688.

3. Ullrich, A.; Schlessinger, J. Cell 1990, 61, 203. Lemmon, M.

A.; Schlessinger, J. Trends Biochem. Sci. 1994, 19, 459.

24, A6B23C43: ¹H NMR (CD₃OD, 400 MHz) d 7.32±

7.24 (m, 14H), 7.24±7.05 (m, 20H), 6.97±6.91 (m, 8H),

5.07 (s, 8H), 4.14±3.94 (m, 24H), 3.59 (m, 4H), 3.45±3.30

(m, 8H), 3.23±3.14 (m, 8H), 2.75 (m, 8H), 2.38 (m, 8H),

1.68±1.40 (m, 16H); IR (®lm) V_max3296, 2948, 1722,

1638, 1464, 1217 cm ¹; ESMS pos: M+Na⁺2273; neg:

M+Cl 2285.

4. Stahl, N.; Yancopoulos, G. D. Cell 1993, 74, 587.

5. Massague, J.; Attisano, L.; Wrana, J. L. Trends Cell Biol.

1994, 4, 172.

6. Smith, C. A.; Farrah, T.; Goodwin, R. G. Cell 1994, 76, 959.

7. Wells, J. A. Proc. Natl. Acad. Sci. U.S.A. 1996, 93, 1. Wells,

J. A. Science 1996, 273, 449.

8. Somers, W.; Ultsch, M.; De Vos, A. M.; Kossiako, A. A.

Nature 1994, 372, 478.

24, A6B23C44: ¹H NMR (CD₃OD, 400 MHz) d 7.36±

7.23 (m, 14H), 7.23±7.13 (m, 8H), 7.08±7.02 (m, 6H),

6.97±6.91 (m, 8H), 5.07 (s, 8H), 4.14±3.94 (m, 24H),

3.65±3.52 (m, 8H), 3.46±3.30 (m, 8H), 3.23±3.14 (m,

9. Wrighton, N. C.; Farrell, F. X.; Chang, R.; Kashyap, A. K.;

Barbone, F. P.; Mulcahy, L. S.; Johnson, D. L.; Barrett, R. W.;

Jollie, L. K.; Dower, W. J. Science 1996, 273, 458. Livnah, O.;

Stura, E. A.; Johnson, D. L.; Middleton, S. A.; Mulcahy, L. S.;

Wrighton, N. C.; Dower, W. J.; Jolie, L. K.; Wilson, I. A.

Science 1996, 273, 464. Watowich, S. S.; Yoshimura, A.;

Longmore, G. D.; Hilton, D. J.; Yoshimura, Y.; Lodish, H. F.

8H), 2.75 (m, 8H), 2.38 (m, 8H), 1.68±1.40 (m, 16H); IR

1

(®lm) V_max3274, 2936, 2365, 1733, 1649, 1458 cm

ESMS pos: M+Na⁺2317; neg: M+Cl 2329.

;

Article Doi

Higher order iminodiacetic acid libraries for probing protein-protein interactions

DOI: 10.1016/S0968-0896(98)00128-X

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