Design and synthesis of potent nonpeptidic farnesyltransferase inhibitors based on a terphenyl scaffold

Article abstract of DOI:10.1021/jm0103099

By modification of key carboxylate, hydrophobic, and zinc-binding groups projected from a sterically restricted terphenyl scaffold, a series of simple and nonpeptide mimetics of the CysVal-Ile-Met tetrapeptide substrate of protein farnesyltransferase (FTase) have been designed and synthesized. A crystal structure of 4-nitro-2-phenyl-3′-methoxycarbonylbiphenyl shows that the triphenyl fragment provides a large hydrophobic surface that potentially mimics the hydrophobic side chains of the three terminal residues in the tetrapeptide. 2-Phenyl-3-(N-(1-(4-cyanobenzyl)-1H-imidazol-5-yl)methyl)amino- 3′carboxylbiphenyl, in which the free thiol group was replaced with a 1-(4-cyanobenzyl)imidazole group, shows submicromolar inhibition activity against FTase in vitro and inhibits H-Ras processing in whole cells.

Full text of DOI:10.1021/jm0103099

J . Med. Chem. 2002, 45, 177-188
177
Design a n d Syn th esis of P oten t Non p ep tid ic F a r n esyltr a n sfer a se In h ibitor s
Ba sed on a Ter p h en yl Sca ffold
J unko Ohkanda,† J effrey W. Lockman,† Mohit A. Kothare,† Yimin Qian,† Michelle A. Blaskovich,‡
Said M. Sebti,‡ and Andrew D. Hamilton*,†
Department of Chemistry, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107,
and Drug Discovery Program, H. Lee Moffitt Cancer Center and Research Institute,
Departments of Oncology and Biochemistry and Molecular Biology, University of South Florida, Tampa, Florida 33612
Received J uly 5, 2001
By modification of key carboxylate, hydrophobic, and zinc-binding groups projected from a
sterically restricted terphenyl scaffold, a series of simple and nonpeptide mimetics of the Cys-
Val-Ile-Met tetrapeptide substrate of protein farnesyltransferase (FTase) have been designed
and synthesized. A crystal structure of 4-nitro-2-phenyl-3′-methoxycarbonylbiphenyl shows that
the triphenyl fragment provides a large hydrophobic surface that potentially mimics the
hydrophobic side chains of the three terminal residues in the tetrapeptide. 2-Phenyl-3-(N-(1-
(4-cyanobenzyl)-1H-imidazol-5-yl)methyl)amino-3′carboxylbiphenyl, in which the free thiol group
was replaced with a 1-(4-cyanobenzyl)imidazole group, shows submicromolar inhibition activity
against FTase in vitro and inhibits H-Ras processing in whole cells.
In tr od u ction
(such as Rho, Rap, and Rac)8 with similar sequences at
the carboxyl terminus, except that the X residue is
leucine, isoleucine, or phenylalanine. GGTase-II cata-
lyzes the geranylgeranylation of Rab proteins, with
particular specificity for CXC, CCXX, or XXCC C-
terminal sequences.9 Because the function of Ras is
dependent on the increase in hydrophobicity that results
from farnesylation, inhibition of FTase has become a
target for blocking oncogenic Ras function and thus drug
design in cancer chemotherapy.10,11
FTase is a heterodimeric zinc metalloenzyme com-
posed of a 48 kDa R-subunit and a 46 kDa â-subunit. A
crystal structure of FTase with a tetrapeptide mimetic
Ac-Cys-Val-Ile-Met(Se)-OH and a farnesylpyrophos-
phate (FPP) analogue bound into the active site shows
that the tetrapeptide adopts an extended conformation
in which the cysteine thiol group coordinates to the
catalytic zinc ion.12 The terminal carboxylate of the
peptide binds to Gln 167R through a hydrogen bond, and
another hydrogen bond is formed between the C-
terminal amide oxygen and the Arg 202â.
Over the past few years, remarkable progress has
been made in the development of synthetic inhibitors
for FTase. We and others have previously reported
peptidomimetics and pseudopeptide derivatives of the
CAAX tetrapeptide sequence.9,13-18 These molecules
showed high inhibitory potency for FTase; however, in
some cases, they retain peptide characteristics such as
a methionine or metabolically unstable cysteine resi-
dues. In this paper, we report the design and synthesis
of a new series of CAAX mimetics as FTase inhibitors
based on a fully nonpeptidic terphenyl scaffold.
The four Ras proteins (H, N, KA and KB) are a family
of 21 kDa GTPases encoded by three ras genes.1 In
normal cells, Ras cycles between its GTP (active)- and
its GDP (inactive)-bound states and plays a crucial
function by transducing intracellular signals from growth
factor receptor tyrosine kinases to several signal trans-
duction pathways, such as the PI3K/Akt and the Raf/
MEK/Erk cascades.2 Single amino acid substitutions at
positions 12, 13, or 61 render Ras GTPase deficient and
therefore lock it in its GTP-bound state resulting in
uncontrolled cell growth. These mutations are found in
over 30% of human cancers, particularly in 50% of colon
and 95% of pancreatic cancers.3 To fulfill its signaling
function, Ras must associate with the plasma mem-
brane. This translocation is facilitated in Ras, and many
other small GTPases, by the attachment of prenyl and,
in some cases, palmitoyl groups onto the surface of the
protein.
Protein prenylation plays a crucial role in intracel-
lular signal transduction. In this process, farnesyl (C15)
or geranylgeranyl (C20) groups are covalently attached
to a key cysteine residue, near the protein carboxyl
terminus, through a thiol alkylation reaction that is
catalyzed by the isoprenyltransferase enzymes.4 Three
classes of the enzymes catalyzing the prenylation of
proteins have been identified in mammalian cells:
protein farnesyltransferase (FTase), type I protein gera-
nylgeranyltransferase (GGTase-I), and type II protein
geranylgeranyltransferase (GGTase-II).5-7 FTase cata-
lyzes farnesylation of proteins (such as Ras, Lamin B,
etc.) with a carboxyl terminal sequence CAAX, where
C is cysteine, A is an aliphatic amino acid, and X is
methionine, serine, alanine, glutamine, or cysteine.
GGTase-I catalyzes geranylgeranylation of proteins
Design
Tetrapeptide Cys-Val-Ile-Met (1, Figure 1), the C-
terminal tetrapeptide sequence of K-Ras-4B, inhibits
FTase in vitro (IC50 ) 340 nM) but is not active in whole
cells. In an attempt to improve its poor membrane
permeability and metabolic instability, we had previ-
* Corresponding author tel, (203)432-5570; fax, (203)432-3221;
e-mail, andrew.hamilton@yale.edu.
† Yale University.
‡ University of South Florida.
10.1021/jm0103099 CCC: $22.00 © 2002 American Chemical Society
Published on Web 12/08/2001

178 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1
Ohkanda et al.
F igu r e 1. Structures of previously reported inhibitors.
ously synthesized a series of peptidomimetics wherein
the hydrophobic Val-Ile dipeptide core was replaced by
a 4-aminobenzoic acid spacer.18 This provided a rigid
and hydrophobic link between the cysteine and the
methionine residues. For example, 2 inhibited FTase
with an IC50 of 150 nM,18 confirming that the central
residues in the tetrapeptide sequence could be replaced
with a structurally defined nonamino acid peptidomi-
metic.
To reduce the peptidic character of 2, the Val-Ile-Met
tripeptide of 1 was replaced with a more conformation-
ally restricted 4-amino-3′-carboxybiphenyl group, re-
sulting in 4. Moreover, further modifications lead to the
introduction of an additional phenyl group onto the
aromatic spacer of 2. The ortho-substituted benzene of
3 represented a better mimic of the hydrophobic side
chains of Val-Ile within tetrapeptide 1. The resulting
compound, FTI-276 (3), showed extremely high inhibi-
tion activity (IC50 ) 0.61 nM), improving by 103 relative
to 1.16
The success of scaffolds 3 and 4 suggested that
combining their structural features (hydrophobic sub-
stitution on the phenyl ring and a C-terminal benzoate)
could lead to improved and entirely nonpeptide FTase
inhibitors. These features would mimic important prop-
erties of CAAX, as the crystal structure of ternary
complex of FTase clearly demonstrates that the sub-
strate (Ac-Cys-Val-Ile-Met(Se)-OH) in the active site is
recognized by (1) hydrogen bonding of the methionine
C-terminal carboxylate with Arg 202â, (2) hydrophobic
interactions of the isobutyl and isopropyl groups of the
Val-Ile dipeptide with a hydrophobic pocket formed by
aromatic residues, and (3) chelation of the thiol group
of cysteine to the active site zinc ion.12 Thus, we further
modified our inhibitor design to optimize the functional-
F igu r e 2. Modified functional groups of nonpeptidic inhibi-
tors.
ity of (a) the carboxylate group, (b) the hydrophobic
group, and (c) the zinc-binding group based on the
biphenyl scaffold, as shown in Figure 2.
Resu lts a n d Discu ssion
(A) Mod ifica tion of th e Ca r boxyl Gr ou p . Previous
work had shown that the location of the carboxyl group
in the 3-position of the biphenyl moiety was important
for FTase inhibition activity.17 We further investigated
the substituent effects on biological activity by varying
the size and polarity of the groups in this position. One
interesting modification was to replace the carboxylic
acid with a tetrazole group, which has been successfully
used as a carboxylate isostere in many enzyme inhibitor
studies.19 The pKa value of a tetrazole (5-6) is very
similar to that of a carboxylic acid20 and should allow
it to interact favorably with carboxylate-binding resi-
dues in the active site of FTase.
The synthesis of the tetrazole-containing compound
8 is shown in Scheme 1. The tetrazole group was formed

Potent Nonpeptidic Farnesyltransferase Inhibitors
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1 179
Sch em e 1. Synthesis of Tetrazole-Containing Compound 8a
a
Reagents: (a) EDCI, HOBt, 80%; (b) Ph3P, DEAD, TMSN3, 48 h; (c) 1N NaOH, 24 h, 53%; (d) H2, Pd/C; (e) N-Boc-S-trityl-cysteinal,
NaBCNH3, 30%; (f) TFA, Et3SiH, 53%.
through Mitsunobu reaction of amide 9 with trimeth-
ylsilyl azide.20 Protection of the tetrazole in 10 with a
triphenylmethyl group failed because conditions re-
quired for reduction of the nitro group lead to cleavage
of the protecting group. Therefore, the tetrazole was left
unprotected in the reductive amination and deprotection
steps with the final product purified by reverse phase
preparative high-performance liquid chromatography
(HPLC).
tives inhibited potently GGTase-I, suggesting that the
biphenyl group is a better mimic of AAM than of AAL.
The results also suggest that methionine replacement
in these inhibitors is better tolerated by FTase than is
leucine replacement by GGTase-I.
(B) Mod ifica tion of th e Hyd r op h obic Gr ou p . The
large increase in potency that came from a phenyl
substituent in FTI-276 (3) on the unsubstituted spacer
in 2 prompted us to modify the biphenyl scaffold of 4
by incorporating a hydrophobic group. Methoxy, pro-
poxy, and phenyl groups were introduced at the 2-posi-
tion of the biphenyl scaffold in 4, as in 12-14.
The ability of these synthetic compounds to inhibit
FTase and GGTase-I in vitro was investigated by using
partially purified FTase and GGTase-I from human
Burkitt lymphoma (Daudi) cells.21 Enzyme preparations
were incubated with [3H]FPP and recombinant H-Ras-
CVLS (FTase) or [3H]GGPP and H-Ras-CVLL (GGTase-
I) in the presence of different concentrations of inhibi-
tors. After the preparations were incubated for 30 min
at 37 °C, the reaction was stopped and filtered on glass
fiber filters to separate free [3H]FPP from [3H]F-Ras.
The IC50 values of 4-8 for the inhibition of FTase are
reported in Table 1. As a comparison, the tetrapeptide
Cys-Val-Ile-Met (1) inhibited FTase with an IC50 of 340
nM. The high potency of 4 bearing a carboxyl group at
the 3-position relative to 1 shows that an appropriately
functionalized biphenyl group can act as an effective
mimic of the extended backbone conformation of the last
three amino acids of the Ras protein. Methylation of the
carboxylic acid, as in 5, or replacement of the carboxyl
group with a hydrogen or methyl group resulted in lower
activity.17 However, replacement of carboxylic acid by
tetrazole as in 8 increased potency by ∼5-fold as
compared to 4. Like the carboxylic acid group, tetrazole
bears a negative charge under neutral aqueous condi-
tions, confirming the importance of an ionic interaction
between the inhibitor and the enzyme active site. The
difference in charge distribution between tetrazole and
carboxylate presumably accounts for their different
inhibition potencies. Furthermore, none of these deriva-
The synthetic procedure for 13 is shown in Scheme
2. Deprotection of the methoxy group under acidic
conditions generated a substituted phenol (15) that was
alkylated to give 16. Reduction of the nitro group
followed by reductive amination provided 17, which was
deprotected to give the final product 13. To synthesize
the terphenyl scaffold in 14, we applied recently devel-
oped Suzuki chloride coupling reactions22,23 for chemose-
lective arylation of commercially available 3-bromo-4-
chloro-nitrobenzene (Scheme 3). The coupling reaction
of 3-bromo-4-chloronitrobenzene with one equivalent of
phenylboronic acid, Pd(PPh3)4 as the catalyst, and K2-
CO3 as the base in 20% EtOH/toluene afforded chloride
1824 in 94% yield. Recently, Buchwald et al. have
reported electron rich and sterically bulky phosphine
ligands as effective additives to activate the Pd0 center.22
By using a Pd(OAc)2/2-(dicyclohexylphosphino)biphe-
nyl22 catalyst system, successive modified Suzuki chlo-
ride couplings of 18 to m-methoxycarbonylphenylboronic

180 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1
Ohkanda et al.
Ta ble 1. IC50 Values for Enzyme Inhibition of CAAX Mimetic FTase Inhibitors
a
b
Where s.d. is given n G 3, otherwise n = 1. Ref 18.
acid25 with K3PO4 as the base under reflux in toluene
gave terphenyl derivative 19 in 86% yield.24 The methyl
ester in 19 was hydrolyzed, and the nitro group was
reduced with stannous chloride to afford amino car-
boxylic acid 21. Reductive amination with protected
cysteinal followed by deprotection gave inhibitor 14.
We have solved the X-ray crystal structure of 4-nitro-
2-phenyl-3′-methoxycarbonylbiphenyl (19), an interme-
diate in the synthesis of 14. The structure gives an
insight into the relative orientation of the three phenyl
rings and shows dihedral angles of 53° for the biphenyl
unit and 45° for the phenyl substituent. Figure 3 shows
a superimposition of the crystal structures of 19 and
the tripeptide fragment (Val-Ile-Met(Se)-OH) from the
FTase complex with the AcCys-Val-Ile-Met(Se)-OH tet-
rapeptide.12 When the nitro-N and the ester-C in 19 are
aligned with the Val-N and the Met carboxylate-C on
the tripeptide, the phenyl substituent occupies a similar
position to the isobutyl group of the Ile residue. Overall,
the triphenyl fragment provides a large hydrophobic
area covering the isopropyl, isobutyl, and part of me-
thylthioethyl groups in the tripeptide.
The FTase inhibition activities of 12-14 are shown
in Table 1. Substitution of hydrogen by alkyloxy or aryl
groups at the 2-position of the biphenyl ring in 4 gave
improved inhibition potency in each case by 3- to 8-fold.
This established that the key hydrophobic interaction
between the active site and the groups at the 2-position
of the inhibitors, preserved on going from the 4-ami-
nobenzoic acid spacer (in 3) to the 4-amino-3′-carboxy-

Potent Nonpeptidic Farnesyltransferase Inhibitors
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1 181
Sch em e 2. Synthesis of 13a
a
Reagents: (a) Pd(OAc)2, acetone/H2O reflux, 83%; (b) KMnO4, pyridine/H2O, reflux, 75%; (c) 48% aqueous HBr, reflux; (d) EtOH,
SOCl2, reflux, 2 steps 88%; (e) n-C3H7I, acetone, K2CO3, reflux, 77%; (f) aqueous NaOH/MeOH; (g) (COCl)2; (h) ButOK, 3 steps 30%; (i)H2,
Pd/C; (j) N-Boc-S-trityl-cysteinal, NaBCNH3, 60%; (k) TFA, Et3SiH.
biphenyl scaffold in 12-14, is important for biological
activity. Moreover, introducing a phenyl group (as in
14) improved the FTase inhibition activity of 4 by 8-fold.
As shown in Figure 3, the phenyl substituent is pre-
sumably located at the same position as the isobutyl side
chain of the Ile residue in Cys-Val-Ile-Met and binds in
the large hydrophobic pocket formed by aromatic resi-
dues in the FTase active site.12 Here again, with the
exception of 14, the derivatives were highly selective
for FTase over GGTase-I.
(C) Mod ifica tion of th e Zin c-Bin d in g Gr ou p . The
free thiol functionality in 14, while important for
binding to the Zn2+ ion, is oxidatively unstable and
complicates further biological evaluations. To overcome
this problem, we and others have previously developed
nonthiol-containing FTase inhibitors in which the cys-
teine residue was replaced by an imidazole.13,26-29 In
this study, a similar strategy would be to replace the
cysteine residue of 14 with alternative Zn2+ ion coordi-
nating groups such as imidazole, arylthiol, and alky-
lthiol groups. The structures of the noncysteine inhibi-
tors 22-38 are shown in Figure 4. It is noteworthy that
these are nonpeptide, achiral derivatives.
p-nitrobenzyl bromide with simultaneous deprotection
gave the corresponding aldehydes 40a 13 and 40b, re-
spectively (Scheme 4). Coupling of 40 with terphenyl
scaffold 20 or 21 under reductive amination conditions
gave imidazole-containing derivatives 24-27, respec-
tively (Scheme 3). Compounds 28 and 29 were derived
from further reduction of the nitro group in 26 and 27.
Protection of the free thiol in p-, m-, or o-mercaptoben-
t
zoic acid with butoxycarbonyl (Boc) and reduction of the
benzoic acids to the alcohols 42a -c via mixed anhydride
formation, followed by Swern oxidation, gave the cor-
responding aldehydes 43a -c, respectively (Scheme 4).
As with the imidazole derivatives, reductive amination
of these aldehydes with 20 or 21 followed by deprotec-
tion under acidic conditions gave the corresponding
mercaptoaryl-containing derivatives 30-33 and 36
(Scheme 3).
The results of an in vitro assay for inhibition of FTase
by 22-38 are shown in Table 1. In most cases, replace-
ment of the cysteine residue of 14 by an imidazole group
as in 22-29 leads to a retention of FTase inhibition
activity with IC50 values at submicromolar levels.
Moreover, introducing a benzyl substituent onto the
nitrogen of the imidazole improved the activity signifi-
cantly. For example, 24, which contains a p-cyanobenzyl
group, showed 5-fold higher inhibition potency against
FTase than nonsubstituted 22. These observations
The representative synthetic approach used for the
preparation of the compounds is shown in Schemes 3
and 4. Protection of 4(5)-imidazocarboxyaldehyde with
a trityl group, followed by alkylation with p-cyano- or

182 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1
Ohkanda et al.
Sch em e 3. Representative Synthesis of FTase Inhibitors Based on a Terphenyl Scaffolda
a
Reagents: (a) Pd(PPh3)4, phenylboronic acid, K2CO3, reflux, overnight, 94%; (b) Pd(OAc)2, m-methoxycarbonylphenylboronic acid,
2-(dicyclohexylphosphino)biphenyl, K3PO4, toluene, 85 °C, 1 h, 86%; (c) LiOH, THF/H2O, reflux, 95%; (d) SnCl2, AcOEt, reflux; (e) R2CHO,
AcOH, NaBH4, room temperature; (f) TFA/CH2Cl2.
Inhibition activity of the achiral compounds in whole
cells was also investigated. The whole cell inhibition of
farnesylation and geranylgeranylation was determined
based on the level of inhibition of H-Ras and Rap1A
processing, respectively. Oncogenic H-Ras-transformed
NIH 3T3 cells were treated with various concentrations
of inhibitors and incubated for 48 h. The cell lysates
were separated on 12.5% sodium dodecyl sulfate poly-
acrylamide gel electrophoresis. The separated proteins
were transferred to nitrocellulose and immunoblotted
using an anti-Ras antibody (Y13-238) or an anti-Rap1
antibody (SC-65). Antibody reactions were visualized
using HRP-conjugated anti-rat or anti-rabbit IgG and
an enhanced chemiluminescence detection system. As
a reference, FTI-215326 and GGTI-29830 were used for
H-Ras and Rap1A processing inhibition, respectively.
F igu r e 3. The crystal structures of tripeptide Val-Ile-Met
The results of the Western blot are shown in Figure 5.
The imidazole derivatives containing p-substituted ben-
zyl groups, 24 (FTI-2312; lanes 12 and 13), 25 (FTI-
2297; lanes 15-19), 26 (FTI-2325; lanes 27 and 28), and
27 (FTI-2307; lanes 8 and 9), inhibited H-Ras processing
at 1-10 µM concentrations, whereas unsubstituted
imidazole derivative 23 (FTI-2296) did not show inhibi-
tion activity (lanes 4 and 5). Mercaptoarylmethylamino
derivatives 30 (FTI-2342; lane 29) and 31 (FTI-2316;
lanes 23 and 24) or mercaptoalkylamido derivatives 37
(FTI-2317; lanes 25 and 26) and 38 (FTI-2306; lanes 6
and 7) did not show whole cell activity. The methyl ester
forms (25 and 27, lanes 15-19 and 8 and 9, IC50 values
∼2 and 4 µM) showed higher inhibition activity against
H-Ras processing than the corresponding free carboxy-
late derivatives (24 and 26, lanes 12 and 13 and 27 and
28, IC50 values ∼10 and 50 µM) suggesting that an
increase of the hydrophobicity of the inhibitors could
lead to higher cell permeability.
(shown below as ball and stick) and that of 19 (shown above
as bold lines): most hydrogens are excluded for clarity.
suggest that the imidazole acts as a chelator to Zn2+
,
and its aromatic substituent binds to a hydrophobic
pocket in FTase. Furthermore, the nitro and cyano
groups were better tolerated than the amino group at
this position. Replacement of the cysteine of 14 by a
mercaptoarylamido or mercaptoarylmethylamino group
(30-36), to rigidify the link between the thiol and the
terphenyl groups, was unsuccessful, presumably due to
the molecules being constrained in a conformation less
optimal for binding to Zn2+. In contrast, 37, in which
the cysteine was replaced by a mercaptoalkylamido
group, retained moderate FTase inhibition activity (IC50
) 3.8 µM). The flexible thiol group may be able to adopt
a more appropriate conformation for binding to the zinc
ion. However, 14 was 200-fold more potent than 37
suggesting that in addition to the thiol group, the
alkylamino group from the reduced cysteine fragment
may play an important role in binding to the FTase
active site.
In summary, we have developed a potent series of
peptidomimetics that inhibit FTase with submicromolar
IC50 values. The inhibitors are based on a terphenyl

Potent Nonpeptidic Farnesyltransferase Inhibitors
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1 183
F igu r e 4. Nonpeptide and achiral inhibitors based on a terphenyl scaffold.
Sch em e 4a
a
Reagents: (a) Ph3CCl, Et3N, DMF, 99%; (b) p-substituted benzylbromide/CH3CN, 60 °C, overnight, 70%; (c) Boc2O, Et3N, DMAP,
THF; (d) EtOCOCl, NaBH4; (e) (COCl)2, DMSO, Et3N.
detector with a Rainin 250 mm × 4.6 mm, 5 µm Microsorb
scaffold that functions as a nonpeptidic mimetic of the
C-18 column. High-resolution mass spectra (HRMS) and low-
key CAAX tetrapeptide substrate of FTase. By incor-
resolution mass spectra (LRMS) were performed on a Varian
porating imidazole and benzoate groups as replacements
MAT-CH-5 (HRMS) or VG 7070 (LRMS) mass spectrometer.
for Cys and Met residues, we have generated simple and
Compounds 14, 34, and 37 were prepared by previously
achiral inhibitors (e.g., 25) that show whole cell inhibi-
tion activity against H-Ras processing.
reported procedures.24
4-Nitr o-3′-[(2-cya n oeth yl)a m in oca r bon yl]bip h en yl (9).
4-Nitro-3′-carboxybiphenyl17 (1.70 g, 7.0 mmol) was coupled
with 3-aminopropionitrile (0.566 mL, 7.70 mmol) by using
EDCI (1.48 g, 1.10 equiv) and HOBt (1.04 g, 1.10 equiv) to
give 9 (1.64 g, 80%). mp 142-143 °C. 1H NMR (CDCl3): δ 8.32
(d, J ) 8.8 Hz, 2H), 8.07 (s, 1H), 7.74-7.81 (m, 4H), 7.59 (t, J
) 7.8 Hz, 1H), 6.67 (br t, 1H, amide), 3.76 (q, J ) 6.1 Hz, 2H),
2.80 (t, J ) 6.1 Hz, 2H). 13C NMR (CDCl3): δ 167.4, 147.4,
146.3, 139.5, 134.5, 130.8, 129.5, 127.9, 126.9, 126.4, 124.2,
118.2, 36.3, 18.5.
Exp er im en ta l Section
Melting points were determined with an Electrothermal
capillary melting point apparatus and are uncorrected. 1H and
13C NMR spectra were recorded on a Bruker AM-500, 400, or
QE-plus 300 spectrometer. Chemical shifts were reported in
δ (ppm) relative to tetramethylsilane. All coupling constants
were described in Hz. Elemental analyses were performed by
Atlantic Microlab, Inc., GA. Flash column chromatography was
performed on silica gel (40-63 µm) under a pressure of about
4 psi. Solvents were obtained from commercial suppliers and
purified as follows: tetrahydrofuran and ether were distilled
from sodium benzophenone ketyl; methylene chloride was
distilled over calcium hydride. All synthesized final compounds
were checked for purity by analytical HPLC, which was
performed using a Rainin HP controller and a Rainin UV-C
4-N-[2-(R)-Am in o-3-m er ca p top r op yl]a m in o-3′-(2H-tet-
r a zol-5-yl)bip h en yl Tr iflu or oa ceta te (8). Compound 9 (1.47
g, 5.0 mmol) was dissolved in 50 mL of tetrahydrofuran (THF).
To this solution were added triphenylphosphine (2.64 g, 10
mmol) and DEAD (1.58 mL, 10.0 mmol) at 0 °C. After the
solution was stirred for 20 min, trimethylsilyl azide (1.34 mL,
10.0 mmol) was added. The mixture was stirred at room

184 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1
Ohkanda et al.
F igu r e 5. Effect of imidazole-containing terphenyl derivatives on processing of H-Ras and Rap1A in NIH 3T3 cells. Western blot
analysis demonstrates the inhibition of farnesylated H-Ras or geranylgeranylated Rap 1A as seen by the band shift from processed
(P) to unprocessed (U) protein. Lanes 1, 14 and 20: vehicle control; lanes 2, and 21: 5 µM FTI-2153;26 lanes 3 and 22: 5 µM
GGTI-298; lanes 4 and 5: 1 and 10 µM FTI-2296 (23); lanes 6 and 7: 1 and 10 µM FTI-2306 (38); lanes 8 and 9: 1 and 10 µM
FTI-2307 (27); lanes 10 and 11: 1 and 10 µM FTI-2310 (29); lanes 12 and 13: 1 and 10 µM FTI-2312 (24); lanes 15-19: 0.1, 0.3,
1, 3, and 10 µM FTI-2297 (25); lanes 23 and 24: 1 and 10 µM FTI-2316 (31); lanes 25 and 26: 1 and 10 µM FTI-2317 (37); lanes
27 and 28: 1 and 10 µM FTI-2325 (26); lane 29: 10 µM FTI-2342 (30).
temperature for 48 h. After the solvents were evaporated, the
residue was dissolved in 10 mL of THF and 10 mL of 1 N
sodium hydroxide was added. The mixture was stirred at room
temperature for 24 h, and then solvents were evaporated. The
residue was extracted into 1 N NaOH solution, and the
aqueous phase was acidified with 1 N HCl. The precipitate
was collected and dried to give 10 (702 mg, 53%).
J ) 8.6 Hz, 2H), 3.50-3.57 (m, 2H, Cys R H, CH2N), 3.42 (m,
1H, CH2N), 2.96 (dd, J ) 4.9, 14.8 Hz, 1H, CH2S), 2.83 (dd, J
) 5.6, 14.8 Hz, 1H, CH2S). 13C NMR (CD3OD): δ 149.3, 143.7,
130.9, 130.8, 130.4, 130.0, 128.9, 125.6, 125.5, 114.5, 53.9, 45.3,
25.3 (expect 11 aromatic C, observed 10). Anal. Calcd for
C
16H18N6S‚1.3CF3COOH‚H2O: C, 45.34; H, 4.32; N, 17.06.
Found: C, 45.47; H, 4.17; N, 17.07.
Compound 10 (530 mg, 2.0 mmol) was dissolved in a mixture
of THF and methanol, and the solution was hydrogenated at
40 psi with Pd-C (5% equiv). Hydrogenation was stopped after
30 min, and the hydrogenated product was treated with N-Boc-
S-trityl-L-cysteinal (1.0 equiv). NaBCNH3 (252 mg, 2.0 eq) was
added, and the mixture was stirred overnight. After the
solvents were evaporated, the residue was extracted with
methylene chloride and 0.5 N HCl. Solvents were evaporated,
and the residue was purified by flash column chromatography
(CH2Cl2:methanol ) 10:1) to give the reductive amination
product 11 (398 mg, 30%). mp 89-90 °C (decomp). 1H NMR
(CDCl3): δ 7.97 (s, 1H), 7.90 (d, J ) 7.7 Hz, 1H), 7.55 (d, J )
7.9 Hz, 1H), 7.35-7.42 (m, 9H), 7.14-7.31 (m, 9H), 6.47 (d, J
) 8.6 Hz, 2H), 4.80 (d, J ) 8.4 Hz, 1H, Boc amide), 3.92 (br,
1H, Cys R H), 3.08 (m, 2H, CH2N), 2.40-2.48 (m, 2H, CH2S),
1.45 (s, 9H, Boc).
4-Nitr o-2-h yd r oxy-3′-eth oxyca r bon ylbip h en yl (15). The
coupling of 1-bromo-2-methoxy-4-nitrobenzene with 3-meth-
ylphenylboronic acid gave 2-methoxy-4-nitro-3′-methylbiphe-
nyl, which was then oxidized to give 2-methoxy-4-nitro-3′-
carboxybiphenyl (75%). This compound (1 g, 3.6 mmol) was
suspended in 25 mL of 48% aqueous HBr and 20 mL of acetic
acid. The mixture was refluxed for 5 h, and then, 50 mL of
water was added. The pale yellow solid was filtered to give
the demethylated product (88%). mp 236-237 °C. This inter-
mediate (730 mg, 2.81 mmol) was mixed with ethanol (25 mL)
and thionyl chloride (0.4 mL, 2 equiv). The mixture was
refluxed for 2 h and then cooled in an ice bath. The precipitate
was filtered off (0.32 g), and the filtrate was first evaporated
and then washed with NaHCO3 to give another fraction of
product (0.48 g, combined yield 98%). mp 201-202 °C. 1H NMR
(acetone-d6): δ 9.55 (s, 1H, phenol), 8.30 (s, 1H), 8.06 (d, J )
7.7 Hz, 1H), 7.84-7.93 (m, 3H), 7.60-7.65 (m, 2H), 4.41 (q, J
) 7.1 Hz, 2H), 1.38 (t, J ) 7.1 Hz, 3H). HRMS (EI): calcd for
The compound prepared above (70 mg) was deprotected with
trifluoroacetic acid (TFA), and the crude product (70% purity
according to analytical HPLC) was purified by preparative
HPLC to give 8 as a hydroscopic TFA salt (28 mg, 53%). mp
C
15H13NO5, 287.0794; observed, 287.0796.
4-Nitr o-2-p r op a n oxy-3′-eth oxyca r bon ylbip h en yl (16).
Compound 15 (750 mg, 2.61 mmol) was dissolved in 20 mL of
acetone, and 1-iodopropane (0.38 mL, 2.50 equiv) and potas-
1
90 °C (decomp). H NMR (CD3OD): δ 8.23 (s, 1H), 7.87 (d, J
) 7.7 Hz, 1H), 7.73 (d, J ) 7.7 Hz, 1H), 7.57 (m, 3H), 6.83 (d,

Potent Nonpeptidic Farnesyltransferase Inhibitors
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1 185
sium carbonate (1.08 g, 3 equiv) were added. The mixture was
refluxed for 5 h and then filtered. The filtrate was evaporated
and then recrystallized from 95% ethanol to give white crystals
NaHCO3. The organic layers were dried with Na2SO4 and then
removed by evaporation to give the product as a yellow solid
(233 mg, 70%). mp 120 °C. 1H NMR (CDCl3): δ 9.73 (s, 1H,
CHO), 8.16 (d, J ) 8 Hz, 2H, ortho to NO2), 7.88 (s, 1H,
NCHN), 7.84 (s, 1H, NCHCCHO), 7.31 (d, J ) 8 Hz, 2H, meta
to NO2), 5.64 (s, 2H, CH2Ar).
1
(657 mg, 77%). mp 90.5-91.0 °C. H NMR (CDCl3): δ 8.27 (s,
1H), 8.09 (d, J ) 7.8 Hz, 1H), 7.92 (d, J ) 8.3 Hz, 1H), 7.82 (s,
1H), 7.75 (d, J ) 7.8 Hz, 1H), 7.48-7.54 (m, 2H), 4.41 (q, J )
7.1 Hz, 2H), 4.07 (t, J ) 6.3 Hz, 2H), 1.86 (m, 2H), 1.43 (t, J
) 7.1 Hz, 3H), 1.01 (t, J ) 7.3 Hz, 3H). HRMS: calcd for
2-P h e n yl-3-(N -(1-(4-n it r ob e n zyl)-1H -im id a zol-5-yl)-
m eth yl)a m in o-3′-ca r boxylbip h en yl (26) Compound 40b (75
mg, 0.32 mmol) and 2124 (94 mg, 0.32 mmol) were added to
MeOH (6 mL) containing 0.4 g of molecular sieves. The solution
was stirred at room temperature under nitrogen for 1 h, after
which acetic acid (262 mg, 4.4 mmol) was added. After 5 min,
NaCNBH3 (40 mg, 0.64 mmol) was added in portions. The
mixture was stirred at room temperature under nitrogen
overnight. The reaction mixture was then extracted from CH2-
Cl2 and saturated NaHCO3. The aqueous layer was extracted
with CH2Cl2, after which the combined organic layers were
washed with brine. The organic layer was then dried with Na2-
SO4, and the solvent was removed by evaporation. The crude
product was purified using flash chromotography (100:40:8 )
CHCl3:acetone:EtOH) and then preparative HPLC to give a
yellow amorphous solid (19 mg, 12%). 1H NMR (CD3OD): δ
8.04 (d, 2H, J ) 9 Hz, ortho to NO2), 7.84 (s, 1H, NCHNAr),
7.69 (m, 2H, Aryl H), 7.19 (d, 2H, J ) 9 Hz, meta to NO2),
7.08 (m, 7H, Aryl H), 6.92 (m, 2H, Aryl H), 6.54 (dd, 1H, J )
8 and 2 Hz, Aryl H), 6.36 (d, 1H, J ) 2 Hz, Aryl H), 5.44 (s,
2H, CH2Ar), 4.19 (s, 2H, CH2N). HRMS (FAB): calcd for
C
18H19NO5, 329.1263; observed, 329.1261.
2-P r op a n oxy-4-N-[2-(R)-N-ter t-bu toxyca r bon yla m in o-
3-(tr ip h en ylm eth yl)th iop r op yl]a m in o-3′-ter t-bu toxyca r -
bon ylbip h en yl (17). Compound 16 was hydrolyzed with
NaOH-MeOH to give 2-propanoxy-4-nitro-3′-carboxybiphenyl
(100%, mp 198-199 °C). This intermediate (513 mg, 1.70
mmol) was converted to an acid chloride with oxalyl chloride
(0.22 mL, 1.5 equiv) and then reacted with KOBut (382 mg,
2.0 equiv) to give 2-propanoxy-4-nitro-3′-tert-butoxycarbonyl-
biphenyl (182 mg) as a pale yellow waxy product after column
1
chromatography purification (30%). H NMR (CDCl3): δ 8.18
(s, 1H), 8.17 (d, J ) 7.7 Hz, 1H), 7.92 (d, J ) 8.3 Hz, 1H), 7.81
(s, 1H), 7.71 (d, J ) 7.5 Hz, 1H), 7.50 (t, 2H), 4.05 (t, J ) 6.3
Hz, 2H), 1.83 (m, 2H), 1.60 (s, 9H), 1.01 (t, J ) 7.3 Hz, 3H).
The above intermediate (124 mg, 0.34 mmol) was hydroge-
nated and then treated with N-Boc-S-trityl-L-cysteinal (1.0
equiv) in the presence of NaBCNH3 (34 mg, 1.5 equiv). After
flash column chromatography (hexane:AcOEt ) 4:1), 17 was
obtained (160 mg, 60%). mp 68-70 °C (decomp). 1H NMR
(CDCl3): δ 8.13 (s, 1H), 7.86 (d, J ) 7.8 Hz, 1H), 7.65 (d, J )
7.8 Hz, 1H), 7.40-7.44 (m, 7H), 7.20-7.38 (m, 9H), 7.14 (d, J
) 8.2 Hz, 1H), 6.20 (m, 2H), 4.58 (br d, J ) 7.2 Hz, 1H, Boc
amide), 3.88 (m, 4H, Cys R H, NH, and OCH2), 3.13 (m, 2H,
CH2N), 2.49 (m, 2H, CH2S), 1.76 (m, 2H, propyl), 1.58 (s, 9H,
But), 1.43 (s, 9H, Boc), 0.97 (t, J ) 7.3 Hz, 3H, propyl). 13C
NMR (CDCl3): δ 166.1, 157.0, 155.5, 148.8, 144.4, 138.9, 133.3,
131.4, 131.3, 130.3, 129.5, 128.0, 127.6, 126.9, 126.7, 119.1,
104.8, 97.1, 80.6, 79.6, 69.7, 67,0, 49.4, 47.2, 34.3, 28.3, 28.2,
22.6, 10.8. Anal. Calcd for C47H54O5N2S: C, 74.40; H, 7.12; N,
3.69; S, 4.22. Found: C, 74.59; H, 7.52; N, 3.54; S, 4.04.
C
30H24O4N4, 505.1875; observed, 505.1874.
2-P h e n yl-3-(N -(1-(4-n it r ob e n zyl)-1H -im id a zol-5-yl)-
m eth yl)a m in o-3′-m eth oxyca r bon ylbip h en yl (27). Com-
pound 40b was reacted with 2024 in a manner similar to that
described for 26. The crude product (yellow oil) was purified
using flash chromotography (CHCl3:acetone:EtOH ) 100:40:
8). After the product was dried under vacuum, a yellow
amorphous solid was obtained (71%). 1H NMR (CDCl3): δ 8.15
(d, 2H, J ) 12 Hz, ortho to NO2), 7.89 (t, 1H, J ) 1.5 Hz, Aryl
H), 7.80 (dt, 1H, J ) 1.5 and 8 Hz, Aryl H), 7.63 (s, 1H, NCHN),
7.16-7.22 (m, 7H, Aryl H), 7.12 (dt, 1H, J ) 2 and 8 Hz, Aryl
H), 7.04 (m, 2H, Aryl H), 6.61 (dd, 1H, J ) 2 and 8 Hz, ortho
to NH), 6.54 (d, 1H, 3 Hz, Aryl H), 5.35 (s, 2H, CH2Ar), 4.18
(d, 2H, 4 Hz, CH2NH), 3.87 (s, 3H, COOCH3), 3.69 (broad, 1H,
NH). 13C NMR (CDCl3): δ 167.14, 147.70, 146.73, 143.50,
141.73, 141.54, 141.18, 134.58, 132.11, 131.57, 130.63, 130.10,
129.93, 129.63, 128.03, 127.67, 127.26, 127.09, 126.81, 124.27,
115.08, 112.49, 52.08, 48.21, 38.32 (expected 22 aryl carbons,
found 21). LRMS (M+): 519.2. HRMS (FAB): calcd for
2-P r op a n oxy-4-N-[2-(R)-a m in o-3-m er ca p top r op yl]a m i-
n o-3′-ca r boxybip h en yl Hyd r och lor id e (13). Compound 17
(100 mg, 0.13 mmol) was deprotected with TFA in the presence
of triethylsilane, and the TFA salt was converted to the
hydrochloride salt to give 13 (45 mg, 79%). mp 170-172 °C
1
(decomp). H NMR (CD3OD): δ 8.18 (s, 1H), 7.89 (d, J ) 7.8
Hz, 1H), 7.68 (d, J ) 7.8 Hz, 1H), 7.44 (t, J ) 7.8 Hz, 1H),
7.20 (d, J ) 8.1 Hz, 1H), 6.56 (s, 1H), 6.53 (d, J ) 8.1 Hz, 1H),
3.94 (t, J ) 6.3 Hz, 2H, OCH2), 3.60 (m, 2H, Cys R H and
CH2N), 3.47 (m, 1H, CH2N), 2.99 (dd, J ) 4.8, 14.6 Hz, 1H,
CH2S), 2.85 (dd, J ) 5.5, 14.6 Hz, 1H, CH2S), 1.74 (m, 2H,
propyl), 0.98 (t, J ) 7.3 Hz, 3H, propyl). LRMS (EI): calcd for
C
31H26O4N4S, 519.2032; observed, 519.2033.
2-P h en yl-3-(N-(1H-im idazol-5-yl)m eth yl)am in o-3′-m eth -
oxyca r bon ylbip h en yl (23). 4(5)-Imidazolecarboxaldehyde
(24 mg, 0.25 mmol) was reacted with 20 (50 mg, 0.17 mmol)
in a manner similar to that described for 26. The crude oil
was purified by flash column chromatography (CHCl3:acetone:
EtOH ) 100:40:8) to give the product as a colorless amorphous
C
19H24O3N2S: 360 (M+, 30), 284 (100).
P r oced u r e for th e Syn th esis of Im id a zole-Con ta in in g
In h ibitor s 22-29. Typ ica l Exa m p le Given for Com p ou n d
26. 1-Tr ip h en ylm eth yl-4-im id a zoleca r boxa ld eh yd e (39).
4(5)-Imidazolecarboxaldehylde (3.0 g, 31 mmol) and Et3N (6.24
g, 62 mmol) were stirred at room temperature in dimethyl-
formamide (DMF) (20 mL) under nitrogen. Triphenylmethyl
chloride (8.7 g, 31 mmol) in DMF (45 mL) was added dropwise,
and the resulting solution was stirred at room temperature
overnight. The mixture was poured into 300 mL of water,
which resulted in a white precipitate. This solid was isolated
by filtration and dissolved in AcOEt (approximately 600 mL).
The solution was dried with sodium sulfate and the solvent
then removed under vacuum to give the product as a white
1
solid (62%). H NMR (CDCl3): δ 7.88 (m, 1H, Aryl H), 7.77-
7.79 (m, 1H, Aryl H), 7.61 (s, 1H, imid-2H), 7.24-7.26 (m, 2H,
Aryl H), 7.08-7.18 (m, 7H, Aryl H), 6.99 (s, 1H, imid-5H), 6.73
(br s, 1H, Aryl H), 6.70 (br s, 1H, Aryl H), 4.37 (s, 2H, CH2N),
3.85 (s, 3H, CO2CH3). LRMS: (M+, intensity 100) calcd for
C
24H21N3O2, 383. HRMS (FAB): calcd, 383.1711; observed,
383.1712.
2-P h en yl-3-(N-(1-(4-cya n ob en zyl)-1H -im id a zol-5-yl)-
m eth yl)a m in o-3′-ca r boxylbip h en yl (24). Compound 21 was
reacted with 40a 13 in a manner similar to that described for
26 (67%). 1H NMR (10% CD3OD in CDCl3): δ 7.92 (s, 1H, Aryl
H), 7.82 (d, J ) 6.4 Hz, 1H, Aryl H), 7.63 (br s, 1H, imid-2H),
7.59 (d, J ) 8.0 Hz, 2H, Aryl H), 7.26 (d, J ) 8.4 Hz, 1H, Aryl
H), 7.06-7.20 (m, 10H, Aryl H and imid-4H), 6.60 (dd, J )
2.4 and 8.0 Hz, 1H, Aryl H), 6.54 (d, J ) 2.4 Hz, 1H, Aryl H),
5.31 (s, 2H, CH2N), 4.16 (s, 2H, CH2NH). LRMS: (M+,
intensity 100) calcd for C31H24N4O2, 485. HRMS (FAB): calcd,
485.1980; observed, 485.1977.
1
solid (10.45 g, 99%). mp 186 °C. H NMR (CDCl3): δ 9.86 (s,
1H, CHO), 7.59 (s, 1H, NCHN), 7.51 (s, 1H, NCHCCHO),
7.32-7.38 (m, 12H, Trt), 7.08-7.12 (m, 7H, Trt).
1-(4-Nit r ob en zyl)-5-im id a zoleca r b oxa ld eh yd e (40b ).
Compound 39 (0.5 g, 1.5 mmol) and 4-nitrobenzyl bromide
(0.33 g, 1.5 mmol) were stirred in acetonitrile (10 mL) at 60
°C under nitrogen overnight. The solvent was removed by
evaporation, and the resulting paste was triturated with
acetone (approximately 20 mL). The resulting solid was
isolated by filtration and extracted with CH2Cl2 and saturated
2-P h en yl-3-(N-(1-(4-cya n ob en zyl)-1H -im id a zol-5-yl)-
m eth yl)a m in o-3′-m eth oxyca r bon ylbip h en yl (25). Com-
pound 20 was reacted with 40a (33 mg, 0.15 mmol) in a

186 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1
Ohkanda et al.
manner similar to that described for 26 (45%). 1H NMR
(CDCl3): δ 7.89 (t, J ) 1.5 Hz, 1H, Aryl H), 7.81 (dt, J ) 2.0
and 7.0 Hz, 1H, Aryl H), 7.60 (s, 1H, imid-2H), 7.59 (d, J )
8.5 Hz, 2H, Aryl H), 7.06-7.22 (m, 11H, Aryl H and imid-4H),
6.61 (dd, J ) 2.5 and 8.0 Hz, 1H, Aryl H), 6.55 (d, J ) 2.5 Hz,
1H, Aryl H), 5.30 (s, 2H, CH2N), 4.17 (d, J ) 5.0 Hz, 2H, CH2-
NH), 3.83 (s, 3H, CO2CH3), 3.68 (br s, 1H, NH). LRMS: (M+,
intensity 100) calcd for C32H26N4O2, 499. HRMS (FAB): calcd,
499.2132; observed, 499.2134.
NMR (CDCl3): δ 1.49 (s, 9H, tBu), 3.60 (br s, 1H, OH), 4.53 (s,
2H, CH2), 7.28 (d, J ) 7.6 Hz, 2H, Aryl H), 7.43 (d, J ) 7.6
Hz, 2H, Aryl H). 13C NMR (CDCl3): δ 28.12, 64.08, 85.51,
127.07, 127.28, 142.60, 128.06.
4-S-(t-Bu toxyca r bon yl)m er ca p toben za ld eh yd e (43a ).
To a solution of oxalyl chloride (55 µL, 0.63 mmol) in dry CH2-
Cl2 (0.5 mL) was added freshly distilled DMSO (96 µL, 1.35
mmol) in dry CH2Cl2 (0.5 mL) by syringe at -70 °C under a
N2 stream. The solution was stirred for 20 min at -70 °C, and
then 42a (126 mg, 1.35 mmol) in CH2Cl2 (0.5 mL) was slowly
added by syringe at -70 °C. After the solution was stirred for
1 h at -70 °C, freshly distilled Et3N (362 µL, 2.60 mmol) was
added, and the bath was removed to allow the temperature to
rise to room temperature. To the solution was added Et2O (50
mL) and saturated NaHCO3, and the organic layer was washed
with H2O and brine and dried (MgSO4). Evaporation of the
solvent gave the product as a colorless oil (111 mg, 90%). The
aldehyde was used for the next step reaction immediately
without further purification. 1H NMR (CDCl3): δ 10.02 (s, 1H,
Aryl H), 7.88 (d, J ) 6.4 Hz, 2H, Aryl H), 7.69 (d, J ) 6.4 Hz,
2-P h en yl-3-(N-(1-(4-a m in ob en zyl)-1H -im id a zol-5-yl)-
m eth yl)a m in o-3′-m eth oxyca r bon ylbip h en yl (28). Com-
pound 26 (58 mg, 0.115 mmol) and SnCl2 (135 mg, 0.60 mmol)
were added to AcOEt (4 mL). A few drops of MeOH were added
to cause 26 to dissolve. The solution was heated at reflux for
2 h, after which it was extracted with AcOEt and saturated
NaHCO3. The combined organic layers were dried over Na2-
SO4 and concentrated to yield a clear oil. The crude product
was purified using flash chromotography (5:1 ) CHCl3:MeOH
followed by 100:40:8 ) CHCl3:acetone:EtOH) yielding a white
oily solid after it was dried under vacuum overnight (1.4 mg,
1
t
2H, Aryl H), 1.52 (s, 9H, Bu). 13C NMR (CDCl3): δ 191.43,
3%). H NMR (CD3OD): δ 7.92 (s, 1H, Aryl H), 7.82 (m, 1H,
Aryl H), 7.55 (s, 1H, Aryl H), 7.27 (d, 2H, J ) 8 Hz, Aryl H),
7.17 (m, 9H, Aryl H), 7.03 (s, 1H, Aryl H), 6.92 (d, 2H, 8 Hz,
Aryl H), 6.62 (m, 4H, Aryl H), 5.08 (s, 2H, CH2Ar), 4.20 (s,
2H, CH2N). LRMS: (M+, intensity 35) calcd, 475.2.
166.18, 136.43, 136.18, 134.37, 127.82, 86.47, 27.91.
2-P h en yl-3-(4-m er ca p to)ben zyla m in o-3′-m eth oxyca r -
bon ylbip h en yl (31). The aldehyde 43a (60 mg, 0.25 mmol)
and 20 (51 mg, 0.17 mmol) were dissolved in CH2Cl2 (1 mL),
and AcOH (20 mg) was added to the mixture. The solution
was stirred for 1 h at room temperature, and then, NaBH4 (9
mg, 0.25 mmol) was added. After the solution was stirred for
an additional 2 h at room temperature, the solvent was
evaporated. The residue was dissolved in CH2Cl2 (50 mL), and
the organic layer was washed with saturated NaHCO3 and
brine and dried (MgSO4). The crude product was purified by
flash column chromatography (hexane:AcOEt ) 4:1) to give
2-phenyl-3-(4-t-butoxycarbonylmercapto)benzylamino-3′-meth-
oxycarbonylbiphenyl as a white fine powder (69 mg, 78%). mp
2-P h en yl-3-(N-(1-(4-a m in ob en zyl)-1H -im id a zol-5-yl)-
m eth yl)a m in o-3′-m eth oxyca r bon ylbip h en yl (29). Com-
pound 27 (81 mg, 0.16 mmol) and SnCl2 (205 mg, 0.91 mmol)
were added to AcOEt (6 mL). The solution was heated under
reflux for 2 h, and then, saturated NaHCO3 (15 mL) was
added. The mixture was extracted, and the aqueous layer was
washed with AcOEt (10 mL, 2×). The combined organic
portions were dried with sodium sulfate, and the solvent was
removed by evaporation. A white amorphous solid was ob-
tained (57 mg, 75%). 1H NMR (CDCl3): δ 7.90 (s, 1H, Aryl H),
7.80 (d, 1H, J ) 7 Hz, Aryl H), 7.53 (s, 1H, NCHN), 7.09-7.21
(m, 8H, Aryl H), 7.06 (s, 1H, NCHCCH2N), 6.89 (d, 2H, J )
10 Hz, meta to NH2), 6.55-6.61 (m, 4H, Aryl H), 5.04 (s, 2H,
CH2Ar), 4.19 (s, 2H, CH2NH), 3.86 (s, 3H, COOCH3), 3.77 (s,
1H, NH). 13C NMR (CDCl3): δ 167.19, 147.07, 146.51, 141.79,
141.49, 138.70, 134.64, 131.48, 130.65, 129.85, 129.77, 129.45,
129.27, 128.49, 128.29, 127.94, 127.60, 126.92, 129.61, 125.38,
115.33, 112.35, 52.03, 48.71, 38.18. LRMS: (M+, intensity 40)
calcd, 489.2. HRMS (FAB): calcd, 489.2991; observed, 489.2993.
Syn th etic P r oced u r e for Ar ylth iol-Con ta in in g In h ibi-
tor s 30-36: Typ ica l Exa m p le Given for Com p ou n d 31.
4-S-(t-Bu toxyca r bon yl)m er ca p toben zoic Acid (41a ). To
a solution of 4-mercaptobenzoic acid (1.0 g, 6.5 mmol), Boc2O
(1.6 g, 7.1 mmol), and DMAP (8 mg, 0.06 mmol) in THF (10
mL) was added Et3N (992 µL, 7.1 mmol), and the mixture was
stirred at room temperature overnight. After the solvent
evaporated, the residual oil was dissolved in AcOEt (100 mL)
and the organic layer was washed with 10% citric acid, brine,
and dried (MgSO4). Evaporation of the solvent gave a crude
pale yellow solid (1.7 g). The crude solid was recrystallized
from an Et2O/petroleum ether mixture to give the product as
colorless crystals (1.4 g, 82%). mp 129-130 °C. 1H NMR
(CDCl3): δ 8.12 (d, J ) 8.4 Hz, 2H, Aryl H), 7.65 (d, J ) 8.4
Hz, 2H, Aryl H), 1.53 (s, 9H, tBu). 13C NMR (CDCl3): δ 134.78,
134.15, 130.66, 130.42, 86.38, 28.17.
1
170-171 °C. H NMR (CDCl3): δ 7.89 (s, 1H, Aryl H), 7.78-
7.81 (m, 1H, Aryl H), 7.52 (d, J ) 8.1 Hz, 2H, Aryl H), 7.43 (d,
J ) 8.1 Hz, 2H, Aryl H), 7.08-7.27 (m, 8H, Aryl H), 6.66-
6.69 (m, 2H, Aryl H), 4.42 (s, 2H, CH2), 4.25 (br s, 1H, NH),
t
3.86 (s, 3H, OCH3), 1.51 (s, 9H, Bu). 13C NMR (CDCl3): δ
167.91, 167.19, 147.43, 141.88, 141.50, 140.69, 135.22, 134.64,
131.58, 130.66, 129.84, 129.79, 129.13, 128.33, 128.10, 127.90,
127.53, 127.38, 126.85, 126.57, 114.88, 111.92, 85.65, 51.99,
47.83, 28.18. LRMS: (M+, intensity 80) calcd for C27H23NO2S,
525. HRMS (FAB): calcd, 525.1975; observed, 525.1974.
To a solution of 2-phenyl-3-(4-t-butoxycarbonylmercapto)-
benzylamino-3′-methoxycarbonylbiphenyl (55 mg, 0.11 mmol)
in CH2Cl2 (1 mL) was added TFA (1 mL), and the solution was
stirred at room temperature for 30 min. Evaporation of the
solvent gave 31 as a yellow amorphous solid (45 mg, 100%).
1H NMR (CDCl3): δ 7.87-7.90 (m, 2H, Aryl H), 7.45 (d, J )
8.8 Hz, 1H, Aryl H), 7.34-7.36 (m, 2H, Aryl H), 7.11-7.23
(m, 9H, Aryl H), 6.95-6.97 (m, 2H, Aryl H), 4.43 (s, 2H, CH2),
3.88 (s, 3H, CO2CH3), 3.47 (br s, 1H, SH). 13C NMR (CDCl3):
δ 167.08, 142.79, 141.00, 139.95, 138.86, 134.39, 134.35,
134.00, 132.23, 131.18, 130.58, 130.16, 129.53, 129.28, 128.52,
128.37, 128.15, 127.65, 126.50, 125.04, 121.95, 56.36, 52.36.
LRMS: (M+, intensity 90) calcd for C27H23NO2S, 424. HRMS
(FAB): calcd, 424.1369; observed, 424.1371.
2-P h en yl-3-(4-m er ca p t o)b en zyla m in o-3′-ca r b oxylb i-
p h en yl (30). Compound 43a and amine 21 were reacted in a
manner similar to that described for 31 to give S-Boc-protected
form 30 as a white solid (23%). mp 138 °C. 1H NMR (CD3OD):
δ 7.93-7.75 (m, 2H, ArH), 7.56 (s, 1H, ArH), 7.38 (m, 4H, ArH),
7.13-6.98 (m, 7H, ArH), 6.60 (m, 2H, ArH), 4.35 (s, 2H,
4-S-(t-Bu toxyca r bon yl)m er ca p toben zyl Alcoh ol (42a ).
To a solution of 41a (600 mg, 2.36 mmol) and NEt3 (362 µL,
2.60 mmol) in THF (10 mL) was added ethyl chloroformate
(248 µL, 2.60 mmol) in THF (2 mL) dropwise at 0 °C. After
the solution was stirred at 0 °C for 30 min, additional dry THF
(15 mL) was added to the mixture and the precipitate was
filtered off. To the filtrate was added NaBH4 (197 mg, 5.20
mmol) at 0 °C, and the mixture was stirred at 0 °C for 1 h.
The reaction was quenched by adding 0.5 N HCl (2 mL) at 0
°C, and the THF was evaporated. The product was extracted
with AcOEt (100 mL) and 5% NaHCO3, and the organic layer
was washed with brine and dried (MgSO4). The crude oil was
purified by flash column chromatography (hexane:AcOEt )
2:1) to give the product as a colorless oil (516 mg, 91%). 1H
ArCH2), 1.41 (s, 9H, (CH3)3C). HRMS (FAB): calcd for C31H29
NO4S, 511.1817; observed, 511.1816.
-
The above compound was deprotected in a manner similar
to that described for 31 to afford 30 as a yellow amorphous
solid (87%). 1H NMR (CDCl3): δ 7.86 (m, 3H, ArH), 7.20-7.04
(m, 12H, ArH and NH or SH), 6.64-6.62 (m, 2H, ArH), 4.95-
4.90 (br s, 1H, SH or NH), 4.29 (s, 2H, ArH). 13C NMR
(CDCl3): δ 170.08, 145.84, 140.62, 140.28, 140.00, 134.05,

Potent Nonpeptidic Farnesyltransferase Inhibitors
J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1 187
130.21, 129.86, 128.39, 128.25, 127.81, 127.55, 127.01, 126.97,
126.80, 126.76, 126.60, 126.36, 126.14, 125.30, 116.01, 113.80,
110.91, 64.50. HRMS (FAB): calcd for C26H21NO2S, 411.1293;
observed, 411.1291.
Deprotection of the above compound by the same procedure
as for 34 gave 35 as a yellow amorphous solid (93%). 1H NMR
(CDCl3): δ 7.96 (s, 1H, Aryl H), 7.93 (s, 1H, Aryl H), 7.88 (dt,
J ) 2.5 and 7.5 Hz, 1H, Aryl H), 7.83 (s, 1H, Aryl H), 7.78 (dd,
J ) 2.5 and 8.5 Hz, 1H, Aryl H), 7.65 (d, J ) 8.0 Hz, 2H, Aryl
H), 7.47 (d, J ) 7.5 Hz, 1H, Aryl H), 7.39 (t, J ) 7.0 Hz, 1H,
Aryl H), 7.21-7.23 (m, 4H, Aryl H), 7.14-7.17 (m, 2H, Aryl
H), 3.89 (s, 3H, CO2CO3). LRMS: (M+, intensity 40) calcd for
2-P h en yl-[4-(3-m er ca p toben zyl)a m in o]-3′-ca r boxylbi-
ph en yl (32). 3-(S-t-Bu toxycar bon yl)m er captoben zoic acid
(41b). This compound was prepared by the same method as
described for 41a . Recrystallization from a Et2O/hexanes
mixture afforded a colorless powder (97%). mp 127-128 °C.
1H NMR (CDCl3): δ 8.27 (s, 1H, Aryl H), 8.13 (d, J ) 7.5 Hz,
1H, Aryl H), 7.77 (d, J ) 7.5 Hz, 1H, Aryl H), 7.51 (t, J ) 8.1
Hz, 1H, Aryl H), 1.52 (s, 9H, Boc). 13C NMR (CDCl3): δ 168.60,
167.47, 139.45, 136.23, 131.19, 130.82, 129.32, 129.16, 86.18,
28.16.
C
27H21NO3S, 440. HRMS (FAB): calcd, 440.1319; observed,
440.1320.
2-P h en yl-3-(2-m er ca p to)ben zyla m in o-3′-m eth oxyca r -
b on ylb ip h en yl (36). 2-(S-t-Bu t oxyca r b on yl)m er ca p t o-
ben zoic a cid (41c). Protection of thiosalicylic acid with Boc2O
was carried out by the same procedure as for 41a to give a
pale yellow solid (83%). This protected acid was used for the
next step reaction without further purification. mp 121-123
3-S-(t-Bu toxyca r bon yl)m er ca p toben zyl Alcoh ol (42b).
This compound was prepared from 41b by the same method
as for 42a (100%). 1H NMR (CDCl3): δ 7.33-7.48 (m, 4H, Aryl
1
°C. H NMR (10% CD3OD in CDCl3): δ 7.97 (dd, J ) 1.6 and
t
H), 4.61 (s, 2H, CH2), 3.30 (br s, 1H, OH), 1.49 (s, 9H, Bu).
7.6 Hz, 1H, Aryl H), 7.69 (dd, J ) 1.2 and 9.2 Hz, 1H, Aryl H),
7.51 (dd, J ) 1.2 and 6.4 Hz, 1H, Aryl H), 7.43 (td, J ) 1.2
13C NMR (CDCl3): δ 168.07, 142.04, 133.81, 133.16, 129.07,
128.50, 127.91, 85.87, 64.42, 27.93.
t
and 6.4 Hz, 1H, Aryl H), 1.50 (s, 9H, Bu). 13C NMR (CDCl3):
3-S-(t-Bu toxyca r bon yl)m er ca p toben za ld eh yd e (43b).
This compound was prepared from 42b by the same method
as for 43a (60%). This aldehyde was used for the next step
reaction immediately without further purification. 1H NMR
(CDCl3): δ 10.02 (s, 1H, CHO), 8.03 (s, 1H, Aryl H), 7.90 (d, J
) 8.0 Hz, 1H, Aryl H), 7.78 (d, J ) 8.0 Hz, 1H, Aryl H), 7.57
δ 168.64, 167.32, 136.09, 131.51, 130.72, 129.39, 128.68,
128.64, 85.55, 27.71.
2-S-(t-Bu toxyca r bon yl)m er ca p toben zyl Alcoh ol (42c).
This compound was prepared from 41c by the same method
as for 42a , and the crude product was purified by flash column
chromatography (hexane:AcOEt ) 10:1 to 4:1) to give the
t
(t, J ) 7.6 Hz, 1H, Aryl H), 1.52 (s, 9H, Bu).
1
product as a colorless oil (65%). H NMR (CDCl3): δ 7.55 (dd,
Compound 43b and amine 21 (0.12 g, 0.42 mmol) were
reacted in a manner similar to 31 to afford the S-Boc-protected
form of 32 as a white solid (10 mg, 4%). mp 150 °C. TLC: Rf,
J ) 1.2 and 7.6 Hz, 1H, Aryl H), 7.50 (dd, J ) 1.2 and 7.6 Hz,
1H, Aryl H), 7.42 (td, J ) 1.6 and 7.6 Hz, 1H, Aryl H), 7.28
(td, J ) 1.6 and 7.6 Hz, 1H, Aryl H), 4.72 (d, J ) 4.4 Hz, 2H,
1
0.41 (silica gel, CHCl2:MeOH 8:1). H NMR (CDCl3:CD3OD )
t
CH2), 2.90 (s, 1H, OH), 1.48 (s, 9H, Bu). 13C NMR (CDCl3): δ
1:1): δ 7.65 (m, 2H, ArH), 7.45-7.28 (s, 4H, ArH), 7.07-6.95
(m, 8H, ArH), 6.60-6.55 (m, 2H, ArH), 4.31 (s, 2H, ArCH2),
1.35 (s, 9H, (CH3)3C). HRMS (FAB): calcd for C31H29NO4S,
511.1817; observed, 511.1816.
168.15, 144.44, 136.56, 130.55, 128.16, 126.39, 86.01, 63.33,
28.07.
2-S-(t-Bu toxyca r bon yl)m er ca p toben za ld eh yd e (43c).
This compound was prepared from 42c by the same method
The above 2-phenyl-4-[3-S-(t-butoxylcarbonyl)mercaptoben-
zyl]amino-3′-carboxylbiphenyl was deprotected to afford 32 as
1
as 43a (79%). H NMR (CDCl3): δ 10.43 (s, 1H, CHO), 8.00-
1
8.03 (m, 1H, Aryl H), 7.54-7.63 (m, 3H, Aryl H), 1.50 (s, 9H,
tBu). This compound was used for the next step reaction
without further purification.
a yellow amorphous solid (7 mg, 88%). H NMR (CDCl3:CD3-
OD ) 1:1): δ 7.66-7.64 (m, 2H, ArH), 7.24-6.95 (m, 13H,
ArH), 6.63 (m, 1H, ArH), 4.27 (s, 2H, ArH). HRMS (FAB):
calcd for C26H21NO2S, 411.1293; observed, 411.1291.
The fully protected compound was prepared from 43c and
20 by the same method as for 31. The crude compound was
purified by column chromatography (hexane:AcOEt ) 10:1)
to give 2-phenyl-3-(2-t-butoxycarbonylmercapto)benzylamino-
2-P h en yl-3-(3-m er ca p to)ben zyla m in o-3′-m eth oxyca r -
bon ylbip h en yl (33). The fully protected form of 33 was
prepared from the reaction of 43b with 20 by the same
procedure as for 31. The crude yellow oil was purified by flash
column chromatography (hexane:AcOEt ) 10:1) to give 2-phen-
yl-3-(3-t-butoxycarbonylmercapto)benzylamino-3′-methoxycar-
bonylbiphenyl as colorless oil (50%). 1H NMR (CDCl3): δ 7.90
(s, 1H, Aryl H), 7.80 (dd, J ) 1.8 and 6.6 Hz, 1H, Aryl H), 7.56
(s, 1H, Aryl H), 7.38-7.47 (m, 3H, Aryl H), 7.25-7.28 (m, 1H,
Aryl H), 7.08-7.20 (m, 7H, Aryl H), 6.67-6.69 (m, 2H, Aryl
H), 4.41 (s, 2H, CH2N), 4.26 (br s, 1H, NH), 3.86 (s, 3H, CO2-
1
3′-methoxycarbonylbiphenyl as a colorless oil (64%). H NMR
(CDCl3): δ 7.79 (dt, J ) 1.5 and 1.5 Hz, 1H, Aryl H), 7.55-
7.60 (m, 2H, Aryl H), 7.43 (td, J ) 1.5 and 8.0 Hz, 1H, Aryl
H), 7.33 (td, J ) 1.5 and 8.0 Hz, 1H, Aryl H), 7.25 (d, J ) 8.0
Hz, 1H, Aryl H), 7.10-7.18 (m, 7H, Aryl H), 6.68-6.69 (m,
2H, Aryl H), 4.52 (s, 2H, NCH2), 4.30 (br s, 1H, NH), 3.86 (s,
t
3H, CO2CH3), 1.48 (s, 9H, Bu). 13C NMR (CDCl3): δ 167.68,
167.19, 147.54, 142.65, 141.97, 141.56, 137.18, 134.66, 131.54,
130.65, 130.58, 129.81, 129.20, 128.82, 128.13, 127.87, 127.53,
127.33, 126.78, 126.51, 114.82, 111.81, 85.93, 51.98, 46.85,
28.13.
t
Me), 1.51 (s, 9H, Bu). LRMS: (M+, intensity 95) calcd for
C
32H31NO4S, 525. HRMS (FAB): calcd, 525.1975; observed,
525.1974.
Deprotection of the above compound by the same manner
Compound 36 was obtained from the deprotection of the
above compound in the same manner as for 31 (100%). 1H
NMR (CDCl3): δ 7.88-7.90 (m, 2H, Aryl H), 7.39-7.49 (m,
3H, Aryl H), 7.15-7.27 (m, 10H, Aryl H), 6.99-7.02 (m, 2H,
Aryl H), 4.72 (s, 2H, CH2), 3.88 (s, 4H, CO2CH3 and SH). 13C
NMR (CDCl3): δ 167.12, 142.65, 140.67, 140.08, 139.04,
134.85, 134.40, 133.73, 132.31, 132.10, 130.98, 130.75, 130.59,
130.31, 130.15, 129.57, 128.46, 128.34, 128.14, 127.92, 127.61,
124.47, 121.44, 54.96, 52.34. LRMS: (M+, intensity 100) calcd
for C27H23NO2S, 424. HRMS (FAB): calcd, 424.1369; observed,
424.1371.
as for 31 gave 33 as a yellow amorphous solid (100%). 1H NMR
(CDCl3): δ 7.88-7.91 (m, 2H, Aryl H), 7.46 (d, J ) 8.0 Hz,
1H, Aryl H), 7.34-7.38 (m, 2H, Aryl H), 7.09-7.24 (m, 10H,
Aryl H), 6.98-7.00 (m, 2H, Aryl H), 4.42 (s, 2H, CH2N), 3.89
(s, 3H, CO2CH3), 3.44 (s, 1H, SH). LRMS: (M+, intensity 100)
calcd for C27H23NO2S, 425. HRMS (FAB): calcd, 425.1252;
observed, 425.1450.
2-P h en yl-4-(3-m er ca p toben zoyl)a m in o-3′-m eth oxyca r -
bon ylbip h en yl (35). The S-protected 35 was prepared by the
reaction of 3-(S-tert-butoxycarbonyl)mercaptobenzoic acid and
1
20 in a similar procedure to 3424 (23%). H NMR (CDCl3): δ
2-P h en yl-4-(3-m er ca p toeth ylca r bon yl)a m in o-3′-m eth -
oxyca r bon ylbip h en yl (38). The S-protected compound was
prepared form S-tbutoxycarbonyl-â-mercaptopropionic acid and
20 by a manner similar to 3724 (61%). 1H NMR (CDCl3): δ
7.91 (s, 1H, Aryl H), 7.85 (dt, J ) 2.1 and 6.0 Hz, 1H, Aryl H),
7.73 (s, 1H, Aryl H), 7.65 (dd, J ) 7.8 and 2.1 Hz, 1H, Aryl H),
7.58 (d, J ) 2.1 Hz, 1H, Aryl H), 7.37 (d, J ) 8.7 Hz, 1H, Aryl
8.03 (s, 1H, Aryl H), 7.95 (s, 2H, Aryl H), 7.93 (s, 1H, Aryl H),
7.87 (dt, J ) 8.0 and 2.5 Hz, 1H, Aryl H), 7.78 (dd, J ) 8.5
and 2.5 Hz, 1H, Aryl H), 7.71 (d, J ) 8.0 Hz, 1H, Aryl H), 7.68
(d, J ) 2.5 Hz, 1H, Aryl H), 7.54 (t, J ) 8.0 Hz, 1H, Aryl H),
7.46 (d, J ) 8.0 Hz, 1H, Aryl H), 7.19-7.23 (m, 4H, Aryl H),
7.14-7.15 (m, 2H, Aryl H), 3.89 (s, 3H, CO2CH3), 1.53 (s, 9H,
Boc).

188 J ournal of Medicinal Chemistry, 2002, Vol. 45, No. 1
Ohkanda et al.
(15) Taveras, A. G.; Deskus, J .; Chao, J .; Vaccaro, C. J .; Njoroge, F.
G.; Vibulbhan, B.; Pinto, P.; Remiszewski, S.; del Rosario, J .;
Doll, R. J .; Alvarez, C.; Lalwani, T.; Mallams, A. K.; Rossman,
R. R.; Afonso, A.; Girijavallabhan, V. M.; Ganguly, A. K.;
Pramanik, B.; Heimark, L.; Bishop, W. R.; Wang, L.; Kir-
schmeier, P.; J ames, L.; Carr, D.; Patton, R.; Bryant, M. S.;
Nomeir, A.; Liu, M. Identification of Pharmacokinetically Stable
3,10-Dibromo-8-chlorobenzocycloheptapyridine Farnesyl Protein
Transferase Inhibitors with Potent Enzyme and Cellular Activi-
ties. J . Med. Chem. 1999, 42, 2651-2661.
(16) Qian, Y.; Marugan, J . J .; Fossum, R. D.; Vogt, A.; Sebti, S. M.;
Hamilton, A. D. Probing the Hydrophobic Pocket of Farnesyl-
transferase: Aromatic Substitution of CAAX Peptidomimetics
Leads to Highly Potent Inhibitors. Bioorg. Med. Chem. 1999, 7,
3011-3024.
(17) Qian, Y.; Vogt, A.; Sebti, S. M.; Hamilton, A. D. Design and
Synthesis of Nonpeptide Ras CAAX Mimetics as Potent Farne-
syltransferase Inhibitors. J . Med. Chem. 1996, 39, 217-223.
(18) Qian, Y.; Blaskovich, M. A.; Saleem, M.; Seong, C. M.; Wathen,
S. P.; Hamilton, A. D.; Sebti, S. M. Design and Structural
Requirements of Potent Peptidomimetic Inhibitors of p21Ras
Farnesyltransferase. J . Biol. Chem. 1994, 269, 12410-12413.
(19) Murry, W. V. Angiotensin II Receptor Antagonists: The Next
Step in the Evolution of Antihypertensive Therapy. Chemtracts
1993, 263-285.
(20) Carini, D. J .; Duncia, J . V.; Aldrich, P. E.; Chiu, A. T.; J ohnson,
A. L.; Pierece, M. E.; Price, W. A.; Santella, J . B.; Wells, G. J .;
Wexler, R. R.; Wong, P. C.; Yoo, S.; Timmermans, P. B.
Nonpeptide Angiotensin II Receptor Antagonists: The Discovery
of a Series of N-(Bisphenylmethyl)imidazoles as Potent, Orally
Active Antihypertensives. J . Med. Chem. 1991, 34, 2525-2547.
(21) Vogt, A.; Qian, Y.; Blaskovich, M. A.; Fossum, R. D.; Hamilton,
A. D.; Sebti, S. M. Nonpeptide Mimetic of Ras-CAAX: Selective
Inhibition of Farnesyltransferase and Ras Processing. J . Biol.
Chem. 1995, 270, 660-664.
(22) Wolfe, J . P.; Singer, R. A.; Yang, B. H.; Buchwald, S. L. Highly
Active Palladium Catalysts for Suzuki Coupling Reactions. J .
Am. Chem. Soc. 1999, 121, 9550-9561.
(23) Littke, A. F.; Dai, C.; Fu, G. C. Versatile Catalysts for the Suzuki
Cross-Coupling of Arylboronic Acids with Aryl and Vinyl Halides
and Triflates under Mild Conditions. J . Am. Chem. Soc. 2000,
122, 4020-4028.
(24) Kothare, M. A.; Ohkanda, J .; Lockman, J . W.; Qian, Y.; Blask-
ovich, M. A.; Sebti, S. M.; Hamilton, A. D. Development of a
Tripeptide Mimetic Strategy for the Inhibition of Protein Far-
nesyltransferase. Tetrahedron 2000, 9833-9841.
(25) Haino, T.; Matsumura, K.; Harano, T.; Yamada, K.; Saijyo, Y.;
Fukuzawa, Y. Synthesis and Binding Behavior of an Artificial
Receptor Based on “Upper rim” Functionalized Calix[5]arene.
Tetrahedron 1998, 54, 12185-12196.
(26) Sun, Z.; Blaskovich, M. A.; Knowles, D.; Qian, Y.; Ohkanda, J .;
Bailey, R. D.; Hamilton, A. D.; Sebti, S. M. Antitumor Efficacy
of a Novel Class of Nonthiol-Containing Peptidomimetic Inhibi-
tors of Farnesyltransferase and Geranylgeranyltransferase I:
Combination Therapy with the Cytotoxic Agents Cisplatin,
Taxol, and Gemcitabine. Cancer Res. 1999, 59, 4919-4926.
(27) Hunt, J . T.; Lee, V. G.; Leftheris, K.; Seizinger, B.; Carboni, J .;
Mabus, J .; Ricca, C.; Yan, N.; Manne, V. Potent, Cell Active,
Nonthiol Tetrapeptide Inhibitors of Farnesyltransferase. J . Med.
Chem. 1996, 39, 353-358.
(28) Anthony, N. J .; Gomez, R. P.; Schaber, M. D.; Mosser, S. D.;
Hamilton, K. A.; O’Neil, T. J .; Koblan, K. S.; Graham, S. L.;
Hartman, G. D.; Shah, D.; Rands, E.; Kolh, N. E.; Gibbs, J . B.;
Oliff, A. I. Design and in Vivo Analysis of Potent Nonthiol
Inhibitors of Farnesyl Protein Transferase. J . Med. Chem. 1999,
42, 3356-3368.
(29) Hunt, J . T.; Ding, C. Z.; Gatorsky, R.; Bednarz, M.; Bhide, R.;
Cho, Y.; Chong, S.; Chao, S.; Gullo-Brown, J .; Guo, P.; Kim, S.-
H.; Lee, F. Y. F.; Leftheris, K.; Miller, A.; Mitt, T.; Patel, M.;
Penhallow, B. A.; Ricca, C.; Rose, W. C.; Schmidt, R.; Slusarchyk,
W. A.; Vite, G.; Manne, V. Discovery of (R)-7-Cyano-2,3,4,5-
tetrahydro-1-(1H-imidazol-4-ylmethyl)-3-(phenylmethyl)-4-(2-
thenylsulfonyl)-1H-1,4-benzodiazepine (BMS-214662), a Farne-
syltransferase Inhibitor with Potent Preclinical Antitumor
Activity. J . Med. Chem. 2000, 43, 3587-3595.
(30) Vogt, A.; Qian, Y. M.; McGuire, T. F.; Hamilton, A. D.; Sebti, S.
M. Protein Geranylgeranylation, not Farnesylation, Is Required
for the G(1) to S Phase Transition in Mouse Fibroblasts.
Oncogene 1996, 13, 1991-1999.
H), 7.08-7.22 (m, 7H, Aryl H), 3.87 (s, 3H, CO2CH3), 3.16 (t,
J ) 6.3 Hz, 2H, CH2S), 2.78 (t, J ) 6.3 Hz, 2H, CH2CO), 1.49
t
(s, 9H, Bu).
The Boc-protected compound was treated with TFA to give
1
38 as a yellow oil (12 mg, 75%). H NMR (CDCl3): δ 7.90 (s,
1H, Aryl H), 7.85 (d, J ) 8.0 Hz, 1H, Aryl H), 7.82 (s, 1H, Aryl
H), 7.39 (d, J ) 8.0 Hz, 1H, Aryl H), 7.16-7.24 (m, 5H, Aryl
H), 7.07-7.09 (m, 2H, Aryl H), 3.89 (s, 3H, CO2CH3), 2.90-
2.94 (m, 2H, SCH2), 2.76 (t, J ) 7.0 Hz, 2H, CH2CO), 1.70 (t,
J ) 7.5 Hz, 1H, SH). LRMS: (M+, intensity 100) calcd for
C
23H21NO3, 392. HRMS (FAB): calcd, 392.1321; observed,
392.1320.
Ack n ow led gm en t. This work was supported by a
grant from the National Institutes of Health (CA67771).
We thank Susan R. DeGala for the X-ray crystal-
lographic analysis.
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
details for 19 (Figure 3) including tables of atomic coordinates,
thermal parameters, bond angles, and bond lengths (17 pages).
This material is available free of charge via the Internet at
http://pubs.acs.org.
Refer en ces
(1) Grand, B. A.; Owen, D. The Biochemistry of Ras p21. Biochem.
J . 1991, 279, 609-631.
(2) J ackson, J . H.; Cochrane, C. G.; Bourne, J . R.; Solski, P. A.; Buss,
J . E.; Der, C. J . Farnesol Modification of Kirsten-Ras Exon 4B-
Protein is Essential for Transformation. Proc. Natl. Acad. Sci.
U.S.A. 1990, 87, 3042-3046.
(3) Barbacid, M. Ras Genes. Annu. Rev. Biochem. 1987, 56, 779-
828.
(4) Casey, P. J . Biochemistry of Protein Prenylation. Lipid Res.
1992, 33, 1731-1740.
(5) Reiss, Y.; Goldstein, J . L.; Seabra, M. C.; Casey, P. A.; Brown,
M. S. Inhibition of Purified p21Ras Farnesyl-Protein Transferase
by Cys-AAX Tetrapeptides. Cell 1990, 62, 81-88.
(6) Chen, W.-J .; Moomaw, J . F.; Overton, L.; Kost, T. A.; Casey, P.
J . High-Level Expression of Mammalian Protein Farnesyltrans-
ferase in a Baculovirus System: The Purified Protein Contains
Zinc. J . Biol. Chem. 1993, 268, 9675-9680.
(7) Yokoyama, K.; Gelb, M. H. Purification of a Mammalian Protein
Geranylgeranyltransferase: Formation and Catalytic Properties
of an Enzyme-Geranylgeranyl Pyrophosphate Complex. J . Biol.
Chem. 1993, 268, 4055-4060.
(8) Der, C. J .; Cox, A. D. Isoprenoid Modification and Plasma-
Membrane Association: Critical Factors for Ras Oncogenicity.
Cancer Cells 1991, 3, 331-340.
(9) Witter, D. J .; Poulter, C. D. Yeast Geranylgeranyltransferase
Type-II: Steady-State Kinetic Studies of the Recombinant
Enzyme. Biochemistry 1996, 35, 925-932.
(10) Gibbs, J . B.; Oliff, A.; Kohl, N. E. Farnesyltransferase Inhibi-
tors: Ras Research Yields a Potential Cancer Therapeutic. Cell
1994, 77, 175-178.
(11) Sebti, S. M.; Hamilton, A. D. Inhibition of Ras Prenylation: A
Novel Approach to Cancer Chemotherapy. Pharmacol. Ther.
1997, 74, 103-114.
(12) Strickland, C. L.; Windsor, W. T.; Syto, R.; Wang, L.; Bond, R.;
Wu, Z.; Schwartz, J .; Le, H. V.; Beese, L.; Weber, P. C. Crystal
Structure of Farnesyl Protein Transferase Complexed with a
CaaX Peptide and Farnesyl Diphosphate Analogue. Biochemistry
1998, 37, 16601-16611.
(13) Williams, T. M.; Bergman, J . M.; Brashear, K.; Breslin, M. J .;
Dinsmore, C. J .; Hutchinson, J . H.; MacTough, S. C.; Stump, C.
A.; Wei, D. D.; Zartman, B.; Bogusky, M. J .; Culberson, J . C.;
Buser-Doepner, C.; Davide, J .; Greenberg, I. B.; Hamilton, K.
A.; Koblan, K. S.; Kohl, N. E.; Liu, D.; Lobell, R. B.; Mosser, S.
D.; O’Neill, T. J .; Rands, E.; Schaber, M. D.; Wilson, F.;
Senderak, E.; Motzel, S. L.; Gibbs, J . B.; Graham, S. L.;
Heimbrook, D. C.; Hartman, G. D.; Oliff, A. I.; Huff, J . R.
N-Arylpiperazinone Inhibitors of Farnesyltransferase: Discovery
and Biological Activity. J . Med. Chem. 1999, 42, 3779-3784.
(14) Williams, T. M.; Ciccarone, T. M.; MacTough, S. C.; Bock, R. L.;
Conner, M. W.; Davide, J . P.; Hamilton, K.; Koblan, K. S.; Kohl,
N. E.; Kral, A. M.; Mosser, S. D.; Omer, C. A.; Pompliano, D. L.;
Rands, E.; Schaber, M. D.; Shah, D.; Wilson, F. R.; Gibbs, J . B.;
Graham, S. L.; Hartman, G. D.; Oliff, A. I.; Smith, R. L.
2-Substituted Piperazines as Constrained Amino Acids: Ap-
plication to the Synthesis of Potent, Noncarboxylic Acid Inhibi-
tors of Farnesyltransferase. J . Med. Chem. 1996, 39, 1345-1348.
J M0103099