Inhibitors of farnesyl-protein transferase

The present invention is directed to compounds which inhibit farnesyl-protein transferase (FTase) and the farnesylation of the oncogene protein Ras. The invention is further directed to chemotherapeutic compositions containing the compounds of this invention and methods for inhibiting farnesyl-protein transferase and treatment of cancer.

BACKGROUND OF THE INVENTION 
The Ras gene is found activated in many human cancers, including colorectal 
carcinoma, exocrine pancreatic carcinoma, and myeloid leukemias. 
Biological and biochemical studies of Ras action indicate that Ras 
functions like a G-regulatory protein, since Ras must be localized in the 
plasma membrane and must bind with GTP in order to transform cells (Gibbs, 
J. et al., Microbiol. Rev. 53:171-286 (1989)). Forms of Ras in cancer 
cells have mutations that distinguish the protein from Ras in normal 
cells. 
At least 3 post-translational modifications are involved with Ras membrane 
localization, and all 3 modifications occur at the C-terminus of Ras. The 
Ras C-terminus contains a sequence motif termed a "CAAX" or "Cys-Aaa.sup.1 
-Aaa.sup.2 -Xaa" box (Aaa is an aliphatic amino acid, the Xaa is any amino 
acid) (Willumsen et al., Nature 310:583-586 (1984)). Other proteins having 
this motif include the Ras-related GTP-binding proteins such as Rho, 
fungal mating factors, the nuclear lamins, and the gamma subunit of 
transducin. 
Farnesylation of Ras by the isoprenoid farnesyl pyrophosphate (FPP) occurs 
in vivo on Cys to form a thioether linkage (Hancock et al., Cell 57:1167 
(1989); Casey et al., Proc. Natl. Acad. Sci. USA 86:8323 (1989)). In 
addition, Ha-Ras and N-Ras are palmitoylated via formation of a thioester 
on a Cys residue near a C-terminal Cys farnesyl acceptor (Gutierrez et 
al., EMBO J. 8:1093-1098 (1989); Hancock et al., Cell 57:1167-1177 
(1989)). Ki-Ras lacks the palmitate acceptor Cys. The last 3 amino acids 
at the Ras C-terminal end are removed proteolytically, and methyl 
esterification occurs at the new C-terminus (Hancock et al., ibid). Fungal 
mating factor and mammalian nuclear lamins undergo identical modification 
steps (Anderegg et al., J. Biol. Chem. 263:18236 (1988); Farnsworth et 
al., J. Biol. Chem. 
Inhibition of Ras farnesylation in vivo has been demonstrated with 
lovastatin (Merck & Co., Rahway, N.J.) and compactin (Hancock et al., 
ibid; Casey et al., ibid; Schafer et al., Science 245:379 (1989)). These 
drugs inhibit HMG-CoA reductase, the rate limiting enzyme for the 
production of polyisoprenoids and the farnesyl pyrophosphate precursor. It 
has been shown that a farnesyl-protein transferase using farnesyl 
pyrophosphate as a precursor is responsible for Ras farnesylation. (Reiss 
et. al., Cell, 62:81-88 (1990); Schaber et al., J. Biol. Chem., 
265:14701-14704 (1990); Schafer et al., Science, 249:1133-1139 (1990); 
Manne et al., Proc. Natl. Acad. Sci USA, 87:7541-7545 (1990)). 
Inhibition of farnesyl-protein transferase and, thereby, of farnesylation 
of the Ras protein, blocks the ability of Ras to transform normal cells to 
cancer cells. The compounds of the invention inhibit Ras farnesylation 
and, thereby, generate soluble Ras which, as indicated infra, can act as a 
dominant negative inhibitor of Ras function. While soluble Ras in cancer 
cells can become a dominant negative inhibitor, soluble Ras in normal 
cells would not be an inhibitor. 
A cytosol-localized (no Cys-Aaa.sup.1 -Aaa.sup.2 -Xaa box membrane domain 
present) and activated (impaired GTPase activity, staying bound to GTP) 
form of Ras acts as a dominant negative Ras inhibitor of membrane-bound 
Ras function (Gibbs et al., Proc. Natl. Acad. Sci. USA 
86:6630-6634(1989)). Cytosol localized forms of Ras with normal GTPase 
activity do not act as inhibitors. Gibbs et al., ibid, showed this effect 
in Xenopus oocytes and in mammalian cells. 
Administration of compounds of the invention to block Ras farnesylation not 
only decreases the amount of Ras in the membrane but also generates a 
cytosolic pool of Ras. In tumor cells having activated Ras, the cytosolic 
pool acts as another antagonist of membrane-bound Ras function. In normal 
cells having normal Ras, the cytosolic pool of Ras does not act as an 
antagonist. In the absence of complete inhibition of farnesylation, other 
farnesylated proteins are able to continue with their functions. 
Farnesyl-protein transferase activity may be reduced or completely 
inhibited by adjusting the compound dose. Reduction of farnesyl-protein 
transferase enzyme activity by adjusting the compound dose would be useful 
for avoiding possible undesirable side effects resulting from interference 
with other metabolic processes which utilize the enzyme. 
These compounds and their analogs are inhibitors of farnesyl-protein 
transferase. Farnesyl-protein transferase utilizes farnesyl pyrophosphate 
to covalently modify the Cys thiol group of Ras, and other cellular 
proteins, with a farnesyl group. Inhibition of farnesyl pyrophosphate 
biosynthesis by inhibiting HMG-CoA reductase blocks Ras membrane 
localization in vivo and inhibits Ras function. Inhibition of 
farnesyl-protein transferase is more specific and is attended by fewer 
side effects than is the case for a general inhibitor of isoprene 
biosynthesis. 
Previously, it has been demonstrated that tetrapeptides containing cysteine 
as an amino terminal residue with the CAAX sequence inhibit Ras 
farnesylation (Schaber et al., ibid; Reiss et al., ibid; Reiss et al., 
PNAS, 88:732-736 (1991)). It was, however, disclosed that tetrapeptides 
which further contained a cyclic amino acid residue, such as proline, had 
greatly reduced inhibitory activity when compared to tetrapeptides not 
containing a cyclic amino acid (Reiss et al., (1991)). Tetrapeptide 
inhibitors may inhibit while serving as alternate substrates for the Ras 
farnesyl-transferase enzyme, or may be purely competitive inhibitors (U.S. 
Pat. No. 5,141,851, University of Texas). 
Recently, it has been demonstrated that certain inhibitors of 
farnesyl-protein transferase selectively block the processing of Ras 
oncoprotein intracellularly (N. E. Kohl et al., Science, 260:1934-1937 
(1993) and G. L. James et al., Science, 260:1937-1942 (1993)). 
Among the inhibitors of farnesyl protein transferase that have been 
described in the art are benzodiazepine derivatives that mimic the CAAX 
motif of a prenylated protein (James, et al., Science, 1993, 260, 
1937-1942). These compounds are potent inhibitors of FPTase. However, the 
compounds described by James, et al., are carboxylic acids which have 
relatively poor activity as inhibitors of farnesylation in intact cells. 
To render such compounds useful for inhibition of the transformed 
phenotype of a cancer cell, esterification of the C-terminal carboxylate 
is required. Such a prodrug strategy significantly complicates the 
clinical application of an FPTase inhibitor by adding additional variables 
to its pharmokinetic and pharmodynamic behavior. 
It is, therefore, an object of this invention to develop non-peptide 
compounds which will inhibit farnesyl-protein transferase and the 
farnesylation of the oncogene protein Ras. It is a further object of this 
invention to develop chemotherapeutic compositions containing the 
compounds of this invention, and methods for producing the compounds of 
this invention. 
It is also the object of the invention to provide a FPTase inhibitor which 
includes substituted piperidine analogs which inhibit farnesyl-protein 
transferase and the farnesylation of the oncogene protein Ras p21, and 
chemotherapeutic compositions containing the compounds of this invention. 
SUMMARY OF THE INVENTION 
The present invention includes substituted piperidine analogs which inhibit 
farnesyl-protein transferase and the farnesylation of the oncogene protein 
Ras p21. This invention also includes chemotherapeutic compositions 
containing the compounds of this invention, methods of inhibiting 
farnesyl-protein transferase and methods for treating cancer. 
The compounds of this invention are illustrated by the Formula I: 
##STR1## 
DETAILED DESCRIPTION OF THE INVENTION 
The compounds of this invention are useful in the inhibition of 
farnesyl-protein transferase and the farnesylation of the oncogene protein 
Ras p21. In an embodiment of this invention, the inhibitors of 
farnesyl-protein transferase are illustrated by Formula I: 
##STR2## 
wherein: R.sup.1 is selected from: 
a) COR, 
b) CO.sub.2 R, 
c) CONHR, 
d) OH, 
e) OCOR, 
f) CN, 
g) CH.sub.2 OR, 
h) NHCOR, 
i) NHSO.sub.2 R, or 
j) COR.sup.5 ; 
R is selected from: 
a) C.sub.1-4 alkyl, unsubstituted or substituted with: 
i) C.sub.1-4 alkoxy, 
ii) NR.sup.3 R.sup.4, 
iii) C.sub.3-6 cycloalkyl, 
iv) aryl or heterocycle; or 
b) aryl or heterocycle; 
R.sup.2 is selected from: aryl, aralkyl, heterocycle, or heteroaralkyl, 
unsubstituted or substituted with one or more of: 
a) C.sub.1-4 alkyl, unsubstituted or substituted with: 
i) C.sub.1-4 alkoxy, 
ii) NR.sup.3 R.sup.4, 
iii) C.sub.3-6 cycloalkyl, or 
iv) aryl or heterocycle; 
b) aryl or heterocycle, 
c) halogen, 
d) OR.sup.3, 
e) NR.sup.3 R.sup.4, 
f) CN, 
g) NO.sub.2, or 
h) CF.sub.3 ; 
R.sup.3 and R.sup.4 are independently selected from: H, C.sub.1-4 alkyl, 
C.sub.3-6 cycloalkyl, heterocycle, aryl, aroyl, heteroaryl, arylsulfonyl, 
heteroarylsulfonyl, unsubstituted or substituted with one or more of: 
a) C.sub.1-4 alkoxy, 
b) aryl or heterocycle, 
c) halogen, or 
d) HO, wherein 
or R.sup.3 and R.sup.4 may be joined in a ring; 
R.sup.5 is selected from: 
a) a naturally occurring amino acid, or 
b) an oxidized form of a naturally occurring amino acid which is: 
i) methionine sulfoxide, or 
ii) methionine sulfone; 
or the pharmaceutically acceptable salt thereof. 
The preferred compounds of this invention are: 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl-L-methionine; 
L-Cysteinyl-4-benzyl isonipecotic acid methyl ester; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl N-methyl amide; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl N-(2-pyridylmethyl) amide; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl N-benzyl amide; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(2-chlorobenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(2,3-dichlorobenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(2,4-dichlorobenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(2,6-dichlorobenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(3-(2-methyl)pyridylmethyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(1-naphthyl)methyl isonipecotic acid methyl ester; 
L-Cysteinyl-4-(1-naphthyl)methyl isonipecotic acid ethyl ester; 
L-Cysteinyl-4-(1-naphthyl)methyl isonipecotic acid benzyl ester; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid 2-pyridylmethyl ester; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid 3-pyridylmethyl ester; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid 4-pyridylmethyl ester; 
L-Cysteinyl-4-benzyl-4-piperidinol; 
L-Cysteinyl-4-acetoxy-4-benzylpiperidine; 
L-Cysteinyl-4-cyano-4-phenylpiperidine; 
L-Cysteinyl-4-acetyl-4-phenylpiperidine; 
L-Cysteinyl-4-methoxymethyl-4-(2-methylbenzyl)piperidine; 
L-Cysteinyl-4-acetamido-4-(2-methylbenzyl)piperidine; 
L-Cysteinyl-4-methylsulfonamido-4-(2-methylbenzyl)piperidine; 
or the pharmaceutically acceptable salts thereof. 
The more preferred compounds of this invention are: 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl N-methyl amide; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl N-(2-pyridylmethyl) amide; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl N-benzyl amide; 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(2-chlorobenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(2,3-dichlorobenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(2,4-dichlorobenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(2,6-dichlorobenzyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(3-(2-methyl)pyridylmethyl)isonipecotic acid methyl ester; 
L-Cysteinyl-4-(1-naphthyl)methyl isonipecotic acid methyl ester; 
L-Cysteinyl-4-(1-naphthyl)methyl isonipecotic acid ethyl ester; 
L-Cysteinyl-4-(1-naphthyl)methyl isonipecotic acid benzyl ester; 
L-Cysteinyl-4-(2-methylbenzyl) isonipecotic acid 2-pyridylmethyl ester; 
L-Cysteinyl-4-(2-methylbenzyl) isonipecotic acid 3-pyridylmethyl ester; 
L-Cysteinyl-4-(2-methylbenzyl) isonipecotic acid 4-pyridylmethyl ester; 
L-Cysteinyl-4-benzyl-4-piperidinol; 
L-Cysteinyl-4-methoxymethyl-4-(2-methylbenzyl)piperidine; 
or the pharmaceutically acceptable salts thereof. 
The most preferred compounds of this invention are: 
L-Cysteinyl-4-(2,3-dichlorobenzyl)isonipecotic acid methyl ester; 
##STR3## 
L-Cysteinyl-4-(2,4-dichlorobenzyl)isonipecotic acid methyl ester; 
##STR4## 
or the pharmaceutically acceptable salts thereof. 
As used herein, "alkyl" is intended to include both branched and 
straight-chain saturated aliphatic hydrocarbon groups having the specified 
number of carbon atoms; "alkoxy" represents an alkyl group of indicated 
number of carbon atoms attached through an oxygen bridge. "Halogen" or 
"halo" as used herein means fluoro, chloro, bromo and iodo. 
As used herein, "aryl" is intended to mean any stable monocyclic, bicyclic 
or tricyclic carbon ring of up to 7 members in each ring, wherein at least 
one ring is aromatic. Examples of such aryl elements include phenyl, 
naphthyl, tetrahydronaphthyl, indanyl, biphenyl, phenanthryl, anthryl or 
acenaphthyl. 
The term "aralkyl" represents a branched or straight-chain saturated 
aliphatic hydocarbon groups having 1 to 4 carbon atoms, attached to any 
stable monocyclic, bicyclic or tricyclic carbon ring of up to 7 members in 
each ring, wherein at least one ring is aromatic. 
The term heterocycle or heterocyclic, as used herein, represents a stable 
5- to 7-membered monocyclic or stable 8- to 11-membered bicyclic or stable 
11-15 membered tricyclic heterocyclic ring which is either saturated or 
unsaturated, and which consists of carbon atoms and from one to four 
heteroatoms selected from the group consisting of N, O, and S(O).sub.m 
(wherein m=0, 1 or 2), and including any bicyclic group in which any of 
the above-defined heterocyclic rings is fused to a benzene ring. The 
heterocyclic ring may be attached at any heteroatom or carbon atom which 
results in the creation of a stable structure. Examples of such 
heterocyclic elements include, but are not limited to, azepinyl, 
benzimidazolyl, benzisoxazolyl, benzofurazanyl, benzopyranyl, 
benzothiopyranyl, benzofuryl, benzothiazolyl, benzothienyl, benzoxazolyl, 
chromanyl, cinnolinyl, dihydrobenzofuryl, dihydrobenzothienyl, 
dihydrobenzothiopyranyl, dihydrobenzothiopyranyl sulfone, furyl, 
imidazolidinyl, imidazolinyl, imidazolyl, indolinyl, indolyl, 
isochromanyl, isoindolinyl, isoquinolinyl, isothiazolidinyl, isothiazolyl, 
isothiazolidinyl, morpholinyl, naphthyridinyl, oxadiazolyl, 2-oxoazepinyl, 
2-oxopiperazinyl, 2-oxopiperdinyl, 2-oxopyrrolidinyl, piperidyl, 
piperazinyl, pyridyl, pyrazinyl, pyrazolidinyl, pyrazolyl, pyrimidinyl, 
pyrrolidinyl, pyrrolyl, quinazolinyl, quinolinyl, quinoxalinyl, 
tetrahydrofuryl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, 
thiamorpholinyl, thiamorpholinyl sulfoxide, thiazolyl, thiazolinyl, 
thienofuryl, thienothienyl, and thienyl. 
The term "heteroaralkyl" is intended to mean a branched or straight-chain 
saturated aliphatic hydocarbon groups having 1 to 4 carbon atoms, attached 
to a stable 5- to 7-membered monocyclic or stable 8- to 11-membered 
bicyclic or stable 11-15 membered tricyclic heterocyclic ring which is 
either saturated or unsaturated, and which consists of carbon atoms and 
from one to four heteroatoms selected from the group consisting of N, O, 
and S(O)m (wherein m=0, 1 or 2), and including any bicyclic group in which 
any of the above-defined heterocyclic rings is fused to a benzene ring. 
The heterocyclic ring may be attached at any heteroatom or carbon atom 
which results in the creation of a stable structure. 
In the present invention, the term "naturally occurring amino acids" 
represents both the D and L enantiomer separately and the racemic mixture 
of the following amino acids, which may be identified both by conventional 
3 letter and single letter abbreviations as indicated below: 
______________________________________ 
Alanine Ala A 
Arginine Arg R 
Asparagine Asn N 
Aspartic acid Asp D 
Asparagine or Asx B 
Aspartic acid 
Cysteine Cys C 
Glutamine Gln Q 
Glutamic acid Glu E 
Glutamine or Glx Z 
Glutamic acid 
Glycine Gly G 
Histidine His H 
Isoleucine Ile I 
Leucine Leu L 
Lysine Lys K 
Methionine Met M 
Phenylalanine Phe F 
Proline Pro P 
Serine Ser S 
Threonine Thr T 
Tryptophan Trp W 
Tyrosine Tyr Y 
Valine Val V 
______________________________________ 
When R.sup.3 and R.sup.4 are joined, the cyclic amine substituent formed is 
a nitrogen containing ring, consisting of 4 to 6 members, optionally 
substituted with one of the following: O, S, or N. Examples of such cyclic 
amines include, but are not limited to: piperidine, piperazine, 
morpholine, azetidine, pyrolidine, and thiazolidine. 
The pharmaceutically acceptable salts of the compounds of this invention 
include the conventional non-toxic salts of the compounds of this 
invention as formed, e.g., from non-toxic inorganic or organic acids. For 
example, such conventional non-toxic salts include those derived from 
inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, 
phosphoric, nitric and the like: and the salts prepared from organic acids 
such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, 
tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, 
glutamic, benzoic, salicylic, sulfanilic, 2-acetoxy-benzoic, fumaric, 
toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, 
trifluoroacetic and the like. 
The pharmaceutically acceptable salts of the compounds of this invention 
can be synthesized from the compounds of this invention which contain a 
basic moiety by conventional chemical methods. Generally, the salts are 
prepared by reacting the free base with stoichiometric amounts or with an 
excess of the desired salt-forming inorganic or organic acid in a suitable 
solvent or various combinations of solvents. 
The compounds of the invention can be synthesized by methods well known in 
the pharmaceutical arts, and the additional methods described below. 
Abbreviations used in the description of the chemistry and in the Examples 
that follow are: 
______________________________________ 
Ac.sub.2 O 
Acetic anhydride; 
Boc t-Butoxycarbonyl; 
BOP Bis(2-oxo-3-oxazolidinyl)phosphonic chloride; 
CBz Benzyloxycarbonyl; 
DMAP 4-Dimethylaminopyridine; 
DMF Dimethylformamide; 
DPPA Diphenylphosphoryl azide; 
EDC 1-(3-Dimethylaminopropyl)-3-ethyl-carbodi- 
imide hydrochloride; 
HOBT 1-Hydroxybenzotriazole hydrate; 
Et.sub.3 N 
Triethylamine; 
EtOAc Ethyl acetate; 
FAB Fast atom bombardment; 
HOOBT 3-Hydroxy-1,2,2-benzotriazin-4(3H)-one; 
HPLC High-performance liquid chromatography; 
KHMDS Potassium bis(trimethylsilyl)amide; 
MsCl Methanesulfonyl chloride; 
NaHMDS Sodium bis(trimethylsilyl)amide; 
Py Pyridine; 
TFA Trifluoroacetic acid; 
THF Tetrahydrofuran; 
Tr Trityl, triphenylmethyl. 
______________________________________ 
Synopsis of Reaction Schemes 1-8: 
The compounds of this invention are prepared as illustrated by Reaction 
Schemes 1-8, in addition to other standard manipulations such as ester 
hydrolysis, cleavage of protecting groups, etc., as may be known in the 
literature or exemplified in the experimental procedures. 
Specifically, Scheme 1 depicts the synthesis of the claimed amide analogs. 
The readily available N-Boc benzyl isonipecotate is alkylated by 
successive treatment with an amide base, such as lithium or sodium 
bis(trimethylsilyl)amide, or lithium diisopropylamide, followed by 
treatment with a 2-methyl benzyl halide. Hydrogenolysis of the benzyl 
ester, over a palladium on charcoal catalyst, furnishes the free 
carboxylic acid which is subsequently transformed into the amide by 
treatment with an amine or amine salt and an appropriate coupling reagent 
such as EDC. Boc deprotection of the piperidine nitrogen with anhydrous 
HCl provides the corresponding HCl salt which is coupled with the 
commercially available protected L-cysteine. Simultaneous amine and thiol 
deprotection with trifluoroacetic acid and triethylsilane, affords the 
claimed amide compounds. 
The claimed ester analogs are prepared as illustrated in Scheme 2 by 
alkylating the readily available N-Boc isonipecotic acid esters with the 
appropriate benzyl halide in a manner similar to that described in Scheme 
1. Subsequent coupling with the L-cysteine and simultaneous deprotection, 
also previously described, affords the ester analogs. 
Scheme 3 depicts the preparation of the claimed pyridylmethyl esters which 
are achieved in a different sequence than those esters indicated in Scheme 
2. In this sequence the N-Boc-4-(2-methylbenzyl)isonipecotic acid is 
converted to the pyridylmethyl ester with the corresponding pyridylmethyl 
carbinol and a coupling reagent such as EDC in combination with a 
catalytic amount of an activator such as DMAP. Subsequent cysteine 
coupling and deprotection as previously illustrated provides the 
pyridylmethyl ester analogs. 
The 4-methoxymethylpiperidine analog is prepared via the route in Scheme 4. 
The benzyl ester of N-Boc 4-(2-methylbenzyl) isonipecotic acid is reduced 
with lithium aluminum hydride to the alcohol and then alkylated by 
treating the sodium salt with methyl iodide. The resulting 
methoxymethylpiperidine is deprotected, coupled with the L-cysteine and 
deprotected as previously described to afford the indicated 
methoxymethylpiperidine analog. 
Scheme 5 shows the simple transformation of commercially available 4-cyano 
and 4-acetyl 4-phenyl piperidines to their products through previously 
described L-cysteine coupling and deprotection. 
The hydroxypiperidine compound and its acetyl derivative are prepared as 
indicated in Scheme 6. Commercially available N-benzyl 4-piperidinone is 
treated with benzyl magnesium chloride to afford the benzyl alcohol. This 
compound is deprotected by hydrogenolysis over 10% palladium on charcoal 
catalyst to the free piperidine compound and then coupled to the protected 
L-cysteine in the previously indicated manner. The hydroxy compound is 
furnished by cysteine deprotection and its acetyl derivative by 
acetylation of the alcohol with acetic anhydride and a catalytic amount of 
DMAP followed by cysteine deprotection. 
The synthesis of the claimed acetamido analog is depicted in Scheme 7. The 
protected 4-(2-methylbenzyl)isonipecotic acid undergoes a Curtius 
rearrangement by treatment with diphenylphosphoryl azide and triethylamine 
to afford the 4- aminopiperidine which is acetylated with acetic anhydride 
and then deprotected with anhydrous HCl. L-cysteine coupling and 
deprotection affords the indicated compound. 
Preparation of the 4-methylsulfonylamido compound is shown in Scheme 8. The 
4-amino-4-(2-methylbenzyl)piperidine is sulfonated with methane sulfonyl 
chloride, deprotected, coupled with the L-cysteine and a final 
deprotection affords the claimed compound. 
##STR5## 
The compounds of this invention inhibit farnesyl-protein transferase and 
the farnesylation of the oncogene protein Ras. These compounds are useful 
as pharmaceutical agents for mammals, especially for humans. These 
compounds may be administered to patients for use in the treatment of 
cancer. Examples of the type of cancer which may be treated with the 
compounds of this invention include, but are not limited to, colorectal 
carcinoma, exocrine pancreatic carcinoma, and myeloid leukemias. 
The compounds of this invention may be administered to mammals, preferably 
humans, either alone or, preferably, in combination with pharmaceutically 
acceptable carriers or diluents, optionally with known adjuvants, such as 
alum, in a pharmaceutical composition, according to standard 
pharmaceutical practice. The compounds can be administered orally or 
parenterally, including the intravenous, intramuscular, intraperitoneal, 
subcutaneous, rectal and topical routes of administration. 
For oral use of a chemotherapeutic compound according to this invention, 
the selected compound may be administered, for example, in the form of 
tablets or capsules, or as an aqueous solution or suspension. In the case 
of tablets for oral use, carriers which are commonly used include lactose 
and corn starch, and lubricating agents, such as magnesium stearate, are 
commonly added. For oral administration in capsule form, useful diluents 
include lactose and dried corn starch. When aqueous suspensions are 
required for oral use, the active ingredient is combined with emulsifying 
and suspending agents. If desired, certain sweetening and/or flavoring 
agents may be added. For intramuscular, intraperitoneal, subcutaneous and 
intravenous use, sterile solutions of the active ingredient are usually 
prepared, and the pH of the solutions should be suitably adjusted and 
buffered. For intravenous use, the total concentration of solutes should 
be controlled in order to render the preparation isotonic. 
The present invention also encompasses a pharmaceutical composition useful 
in the treatment of cancer, comprising the administration of a 
therapeutically effective amount of the compounds of this invention, with 
or without pharmaceutically acceptable carriers or diluents. Suitable 
compositions of this invention include aqueous solutions comprising 
compounds of this invention and pharmacologically acceptable carriers, 
e.g., saline, at a pH level, e.g., 7.4. The solutions may be introduced 
into a patient's intramuscular blood-stream by local bolus injection. 
When a compound according to this invention is administered into a human 
subject, the daily dosage will normally be determined by the prescribing 
physician with the dosage generally varying according to the age, weight, 
and response of the individual patient, as well as the severity of the 
patient's symptoms. 
In one exemplary application, a suitable amount of compound is administered 
to a mammal undergoing treatment for cancer. Administration occurs in an 
amount between about 0.1 mg/kg of body weight to about 60 mg/kg of body 
weight per day, preferably of between 0.5 mg/kg of body weight to about 40 
mg/kg of body weight per day.

EXAMPLES 
Examples provided are intended to assist in a further understanding of the 
invention. Particular materials, species and conditions employed are 
intended to be further illustrative of the invention and not limitative of 
the reasonable scope thereof. 
EXAMPLE 1 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl-L-methionine 
Step 1: Preparation of N-t-butoxycarbonyl isonipecotic acid 
To a solution of isonipecotic acid (25.8 g, 200 mmol) in 1 M aqueous NaOH 
(223 ml, 223 mmol) was added a solution of di t-butyl dicarbonate in 200 
ml THF over 1 hour. The resulting solution was stirred at room temp. 
overnight. The reaction mixture was then concentrated in vacuo to remove 
the THF and the residual aqueous solution extracted with hexane 
(2.times.125 ml). The hexane extracts were combined and back extracted 
with saturated NaHCO.sub.3 (2.times.100 ml). All of the basic aqueous 
solutions were combined and cooled to 0.degree. C. and then acidified with 
a 15% aqueous KHSO.sub.4 solution to a pH of 1-2. The resulting thick 
slurry was extracted with EtOAc (4.times.), combined and washed with 
brine, dried over MgSO.sub.4 and concentrated in vacuo to afford the 
product as a white solid. 
Step 2: Preparation of N-t-butoxycarbonyl isonipecotic acid benzyl ester 
To a solution of N-t-butoxycarbonyl isonipecotic acid (12.0 g, 52.3 mmol) 
in 100 ml of anhydrous CH.sub.2 Cl.sub.2, was added benzyl alcohol (6.0 
ml, 58 mmol), followed by 1-(3-dimethylamino-propyl)-3-ethylcarbodiimide 
hydrochloride (11.04 g, 57.6 mmol), and 4-dimethylaminopyridine (642 mg, 
5.25 mmol). The resulting mixture was stirred for 6 hours then diluted 
with CH.sub.2 Cl.sub.2 (150 ml) and washed successively with H.sub.2 O, 
10% aqueous citric acid, saturated NaHCO.sub.3, brine and then dried over 
MgSO.sub.4. Concentration in vacuo afforded a colorless oil which was 
chromatographed on silica with 20% EtOAc/hexane as eluent. Appropriate 
fractions were combined and concentrated in vacuo to afford the product as 
a white solid. 
Step 3: Preparation of N-t-butoxycarbonyl-4-(2-methylbenzyl) isonipecotic 
acid benzyl ester 
To a cold (-78.degree. C.) solution of N-t-butoxycarbonyl isonipecotic acid 
benzyl ester (13.34 g, 41.8 mmol) in 140 ml of dry THF was added a 1.0 M 
THF solution of sodium bis trimethysilylamide (59 ml, 59 mmol) over 15 
min. The resulting orange solution was stirred at -78.degree. C. for 1 h 
and then treated dropwise with .alpha.-bromo-o-xylene (6.8 ml, 50.7 mmol) 
and then allowed to warm slowly to room temp. overnight. The reaction was 
quenched with saturated aqueous NH.sub.4 Cl, diluted with H.sub.2 O, and 
extracted with EtOAc (2.times.). The combined organic extracts were washed 
with brine (2.times.), and concentrated in vacuo to an orange gum. Flash 
chromatography on silica with 20% to 30% EtOAc/hexane as eluent, combining 
appropriate fractions, and concentrating in vacuo, afforded the product as 
a white solid. 
Step 4: Preparation of N-t-butoxycarbonyl-4-(2-methylbenzyl) isonipecotic 
acid 
A mixture of 4-(2-methylbenzyl) N-t-butoxycarbonyl isonipecotic acid benzyl 
ester (2.36 g, 5.57 mmol), 5% Palladium on charcoal catalyst (250 mg), and 
glacial acetic acid (3 ml) in methanol (75 ml), was hydrogenated at 51 
p.s.i. overnight, in a Parr shaker. The reaction mixture was then filtered 
through a pad of Celite and the pad washed several times with methanol. 
The combined filtrates were then concentrated in vacuo to the product, a 
white solid. 30 mg of this material was recrystallized from toluene to 
afford fine white crystals m.p. 176.degree.-179.degree. C. dec. 
Step 5: Preparation of N-t-butoxycarbonyl-4-(2-methylbenzyl) 
isonipecotyl-L-methionine methyl ester 
A solution of the acid (302 mg, 0.91 mmol) in 5 ml DMF was treated in 
succession with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide 
hydrochloride (191 mg, 1.0 mmol), 1-hydroxybenzotriazole hydrate (135 mg, 
1.0 mmol), L-methionine methyl ester hydrochloride (182 mg, 0.91 mmol), 
and diisopropylethylamine (0.17 ml, 1.0 mmol). The resulting mixture was 
stirred at room temp. overnight. The reaction solution was then 
concentrated in vacuo and partitioned between EtOAc and H.sub.2 O. The 
EtOAc layer was then washed with brine, dried over MgSO.sub.4 and 
concentrated in vacuo to a light brown gum. This material was then 
chromatographed on silica with 30% EtOAc/hexane to afford, after combining 
and concentrating the appropriate fractions, the product as a colorless 
gum. 
Step 6: Preparation of 4-(2-methylbenzyl)isonipecotyl-L-methionine methyl 
ester HCl salt 
A stream of anhydrous HCl gas was bubbled through a cold (0.degree. C.) 
solution of (N-t-butoxycarbonyl-4-(2-methylbenzyl) isonipecotyl) 
L-methionine methyl ester (315 mg, 0.66 mmol) in 30 ml of EtOAc for 10 
min. and the reaction solution stirred 1 h more at 0.degree. C. The 
solution was then purged with argon for 10 min. and allowed to warm to 
room temp. Concentration of the solution in vacuo afforded the product as 
a colorless gum. 
Step 7: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl-L-m 
ethionine methyl ester 
A solution of N-t-butoxycarbonyl-S-trityl-L-Cysteine (306 mg, 0.66 mmol), 
in 6 ml DMF under argon, was treated in succession with 
1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (132 mg, 0.69 
mmol), 1-hydroxybenzotriazole hydrate (93 mg, 0.69 mmol), HCl salt (280 
mg, 0.67 mmol), and diisopropylethylamine (0.12 ml, 0.69 mmol). The 
resulting mixture was stirred at room temp. overnight. The reaction 
solution was then concentrated in vacuo and partitioned between EtOAc and 
H.sub.2 O. The EtOAc layer was then washed with brine, dried over 
MgSO.sub.4, and concentrated in vacuo to a light brown gum. This material 
was then chromatographed on silica with 40% EtOAc/hexane to afford, after 
combining and concentrating the appropriate fractions, the product as a 
white foam. 
Step 8: Preparation of 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl-L-methionine methyl ester 
trifluoroacetic acid salt 
To a solution of methyl ester (75 mg, 0.09 mmol) in 2 ml CH.sub.2 Cl.sub.2, 
was added trifluoroacetic acid (1 ml) followed by triethylsilane (0.059 
ml, 0.36 mmol). The solution was stirred for 1.5 h at room temp. and then 
concentrated in vacuo. The residue was partitioned between a 0.1% aqueous 
trifluoroacetic acid solution (5 ml) and hexane. The aqueous layer was 
washed with hexane (4.times.) and then concentrated in vacuo to a gum. 
This material was then purified by preparative HPLC on a VYDAC C.sup.18 
protein and peptide column (22 mm diam.) and a 0.1% aqueous 
trifluoroacetic acid/CH.sub.3 CN mobile phase. The appropriate fractions 
were combined and lyophilized overnight to afford the product a white 
fluffy solid. 
Anal. Calc'd for C.sub.23 H.sub.35 N.sub.3 O.sub.4 S.sub.2 1.30 CF.sub.3 
CO.sub.2 H 0.25 H.sub.2 O: C, 48.47; H, 5.85; N, 6.62. Found: C, 48.49; H, 
5.83; N, 6.83. 
Step 9: Hydrolysis of Me ester 
A 10 mmolar solution of the hydrolyzed methyl ester was generated in situ 
for enzyme assay by treating a solution of methionine methyl ester (3.9 
mg, 6.15 micromol), in methanol (0.050 ml), with a 1.0 M aqueous NaOH 
solution (0.024 ml, 24 micromol). After agitating for 30 sec. and standing 
at room temp for 2 h the solution was diluted with methanol (0.540 ml) to 
afford a 10 mmolar solution of the sodium salt of the hydrolyzed ester. 
The hydrolysis was monitored by HPLC for completeness. 
EXAMPLE 2 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl N-methyl amide trifluoroacetic 
acid salt 
Step 1: Preparation of N-t-butoxycarbonyl-4-(2-methylbenzyl) 
isonipecotyl-N-methyl amide 
A solution of N-t-butoxycarbonyl-4-(2-methylbenzyl) isonipecotic acid (167 
mg, 0.50 mmol) in DMF (5 ml) was treated in succession with 
1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (105 mg. 0.55 
mmol), 1-hydroxybenzotriazole hydrate (75 mg, 0.56 mmol), methylamine 
hydrochloride (38 mg, 0.56 mmol), and diisopropylethylamine (0.097 ml, 
0.56 mmol). The resulting mixture was stirred at room temp. overnight. The 
reaction solution was then concentrated in vacuo and partitioned between 
EtOAc and H.sub.2 O. The EtOAc layer was isolated and the aqueous layer 
extracted with EtOAc (2.times.). The EtOAc extracts were combined and 
washed with brine, dried over MgSO.sub.4, and concentrated in vacuo to a 
light brown gum. This material was then chromatographed on silica with 40% 
EtOAc/hexane to afford, after combining and concentrating the appropriate 
fractions, the product as a colorless gum. 
Step 2: Preparation of 4-(2-methylbenzyl)isonipecotyl-N-methyl amide 
hydrochloride salt 
The N-t-butoxycarbonyl deprotection procedure as described above in Example 
1, Step 6 was utilized to afford the product as a white solid. 
Step 3: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl-N-m 
ethyl amide 
The coupling procedure as described above in Example 1, Step 7 was utilized 
to afford the product as a white foam. 
Step 4: Preparation of L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl-N-methyl 
amide trifluoroacetic acid salt 
Cysteine deprotection as described above in Example 1, Step 8 afforded the 
product as a white fluffy solid. 
Anal. Calc'd for C.sub.18 H.sub.27 N.sub.3 O.sub.2 S 1.25 CF.sub.3 CO.sub.2 
H 0.45 H.sub.2 O: C, 49.23; H, 5.87; N, 8.40. Found: C, 49.25; H, 5.87; N, 
8.46. 
EXAMPLE 3 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl N-(2-pyridylmethyl) amide 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 2, 
substituting (2-aminomethyl) pyridine in Step 1. The amide bis 
trifluoroacetic acid salt was obtained as a white fluffy solid. 
Anal. Calc'd for C.sub.23 H.sub.30 N.sub.4 O.sub.2 S 2.25 CF.sub.3 CO.sub.2 
H 0.65 H.sub.2 O: C, 47.54; H, 4.87; N, 8.06. Found: C, 47.50; H, 4.87; N, 
8.09. 
EXAMPLE 4 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotyl N-benzyl amide trifluoroacetic 
acid salt 
The titled compounds were prepared according to the methods of Example 2, 
substituting benzylamine in Step 1. The amide trifluoroacetic acid salt 
was obtained as a white fluffy solid. 
Anal. Calc'd for C.sub.24 H.sub.31 N.sub.3 O.sub.2 S 1.30 CF.sub.3 CO.sub.2 
H 0.50 H.sub.2 O: C, 54.82; H, 5.76; N, 7.21. Found: C, 54.83; H, 5.72; N, 
7.30. 
EXAMPLE 5 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid methyl ester 
trifluoroacetic acid salt 
Step 1: Preparation of N-t-butoxycarbonyl isonipecotic acid methyl ester 
To an ice cold solution of N-t-butoxycarbonyl isonipecotic acid (8.8 g, 
34.9 mmol), in a 10% mixture of methanol in benzene (250 ml), was added a 
2.0 M solution of trimethylsilyldiazomethane in hexanes, dropwise, until a 
consistent yellow color was obtained (.about.30 ml). After vigorous gas 
evolution had ceased, cooling was removed and the reaction mixture stirred 
for 1 h at room temperature. The mixture was then treated dropwise with 
glacial acetic acid until all yellow color had dissipated. It was then 
stirred 15 min. and concentrated in vacuo to a pale yellow oil. This 
material was purified by column chromatography on silica with 20% 
EtOAc/hexane as eluent. The appropriate fractions were combined and 
concentrated in vacuo to afford the product as a colorless oil. 
Step 2: Preparation of N-t-butoxycarbonyl-4-(2-methylbenzyl)isonipecotic 
acid methyl ester 
N-t-butoxycarbonyl isonipecotic acid methyl ester was transformed utilizing 
the alkylation procedure as described in Example 1, Step 3 substituting 
lithium diisopropylamide as the base to afford the product as a yellow 
syrup. 
Step 3: Preparation of 4-(2-methylbenzyl)isonipecotic acid methyl ester HCl 
salt 
4-(2-methylbenzyl) N-t-butoxycarbonyl isonipecotic acid methyl ester was 
deprotected as described above in Example 1, Step 6 to afford the product 
as a white solid. 
Step 4: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-(2-methylbenzyl)isonipecotic 
acid methyl ester 
The HCl salt was coupled to N-t-butoxycarbonyl-S-trityl-L-Cysteine 
utilizing the procedure described in Example 1, Step 7 to afford the 
product as a white foam. 
Step 5: Preparation of L-Cysteinyl-4-(2-methylbenzyl)isoniopecotic acid 
methyl ester Trifluoroacetic acid salt 
The methyl ester was deprotected and purified as described in Example 1, 
Step 8 to afford the product as a white fluffy solid. 
Anal. Calc'd for C.sub.23 H.sub.35 N.sub.3 O.sub.4 S.sub.2 1.30 CF.sub.3 
CO.sub.2 H 0.25 H.sub.2 O: C, 49.17; H, 5.57; N, 5.57. Found: C, 49.16; H, 
5.55; N, 5.80. 
EXAMPLE 6 
L-Cysteinyl-4-benzyl isonipecotic acid methyl ester trifluoroacetic acid 
salt 
The titled compounds were prepared according to the methods of Example 4, 
substituting benzyl bromide in Step 2. The methyl ester trifluoroacetic 
acid salt was obtained as a white fluffy solid. 
Anal. Calc'd for C.sub.17 H.sub.24 N.sub.2 O.sub.3 S 1.20 CF.sub.3 CO.sub.2 
H: C, 49.23; H, 5.37; N, 5.92. Found: C, 48.91; H, 5.28; N, 5.94. 
EXAMPLE 7 
L-Cysteinyl-4-(2-chlorobenzyl)isonipecotic acid methyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 4, 
substituting 2-chlorobenzyl bromide in Step 2. The methyl ester 
trifluoroacetic acid salt was obtained as a white fluffy solid. 
Anal. Calc'd for C.sub.17 H.sub.23 ClN.sub.2 O.sub.3 S 1.40 CF.sub.3 
CO.sub.2 H: C, 44.83; H, 4.64; N, 5.28. Found: C, 44.64; H, 4.66; N, 5.30. 
EXAMPLE 8 
L-Cysteinyl-4-(2,3-dichlorobenzyl)isonipecotic acid methyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 4, 
substituting 2,3-dichlorobenzyl bromide (prepared from 2,3-dichlorotoluene 
according to the procedure described in J. Chem. Res. (S) (1984) 24.) in 
Step 2. The methyl ester trifluoroacetic acid salt was obtained as a white 
solid. 
Anal. Calc'd for C.sub.17 H.sub.22 N.sub.2 O.sub.3 S 1.55 CF.sub.3 CO.sub.2 
H 0.15 H.sub.2 O: C, 41.28; H, 4.11; N, 4.79. Found: C, 41.26; H, 4.09; N, 
5.11. 
EXAMPLE 9 
L-Cysteinyl-4-(2,4-dichlorobenzyl)isonipecotic acid methyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 4, 
substituting .alpha., 2,4-trichlorotoluene in Step 2. The methyl ester 
trifluoroacetic acid salt was obtained as a white solid. 
Anal. Calc'd for C.sub.17 H.sub.22 N.sub.2 O.sub.3 S 1.55 CF.sub.3 CO.sub.2 
H: C, 41.48; H, 4.08; N, 4.81. Found: C, 41.51; H, 4.08; N, 4.98. 
EXAMPLE 10 
L-Cysteinyl-4-(2,6-dichlorobenzyl)isonipecotic acid methyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 4, 
substituting .alpha., 2,6-trichlorotoluene in Step 2. The methyl ester 
trifluoroacetic acid salt was obtained as a white fluffy solid. 
Anal. Calc'd for C.sub.17 H.sub.22 N.sub.2 O.sub.3 S 1.25 CF.sub.3 CO.sub.2 
H 0.15 H.sub.2 O: C, 42.54; H, 4.31; N, 5.09. Found: C, 42.55; H, 4.30; N, 
5.11. 
EXAMPLE 11 
L-Cysteinyl-4-(3-(2-methyl)pyridylmethyl)isonipecotic acid methyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 4, 
substituting 3-(chloromethyl)-2-methyl pyridine (preparation described 
below). The methyl ester bis trifluoroacetic acid salt was obtained as a 
colorless gum. 
Anal. Calc'd for C.sub.17 H.sub.25 N.sub.3 O.sub.3 S 1.45 CF.sub.3 CO.sub.2 
H 0.30 H.sub.2 O: C, 41.34; H, 4.44; N, 6.60. Found: C, 41.33; H, 4.44; N, 
6.74. 
Preparation of 3-(Chloromethyl)-2-methyl pyridine 
Step 1: Preparation of 3-hydroxymethy-2-methylpyridine 
To a suspension of lithium aluminum hydride (2.0 g, 53 mmol) in anhydrous 
ether (300 ml) was added a solution of methyl-2-methylpyridine carboxylate 
(8.14 g, 53.8 mmol) in 100 ml anhydrous ether over 20 min. The reaction 
mixture was stirred 1.5 h at room temp. and the treated carefully in 
succession with 2 ml of water, 2 ml of 15% aqueous sodium hydroxide, and 6 
ml of water. The white slurry was stirred 1 h at room temp. and then 
filtered through Celite. After several washings with ether, the combined 
filtrates were washed with brine, dried (MgSO.sub.4), and concentrated in 
vacuo to a pale yellow oil. This material was purified by column 
chromatography on silica with 5% methanol/chloroform as eluent to afford 
the product as a colorless oil. 
Step 2: Preparation of 3-chloromethyl-2-methylpyridine 
To a solution of 3-hydroxymethy-2-methylpyridine (0.65 g, 5.3 mmol) in dry 
benzene (5 ml) was added triethylamine (1.0 ml, 7.4 mmol) followed by 
methanesulfonyl chloride (0.78 ml, 10.1 mmol) dropwise over 5 min. The 
heterogeneous dark gummy mixture was stirred at room temp. overnight. The 
reaction was filtered through Celite and washed with benzene (2.times.). 
The combined filtrates were washed with brine, dried (Na.sub.2 SO.sub.4), 
and concentrated in vacuo to the crude product as a yellow oil which was 
used as is. 
EXAMPLE 12 
L-Cysteinyl-4-(1-naphthyl)methyl isonipecotic acid methyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 4, 
substituting 1-(bromomethyl) naphthalene (preparation described below) and 
lithium diisopropylamide as the base in Step 2. The methyl ester 
trifluoroacetic acid salt was obtained as a white fluffy solid. 
Anal. Calc'd for C.sub.21 H.sub.26 N.sub.2 O.sub.3 S 1.25 CF.sub.3 CO.sub.2 
H 0.95 H.sub.2 O: C, 51.68; H, 5.38; N, 5.13. Found: C, 51.64; H, 5.43; N, 
5.14. 
Preparation of 1-(bromomethyl) naphthalene 
To a suspension of triphenylphosphine (10.5 g, 40 mmol) and carbon 
tetrabromide (13.3 g, 40 mmol) in anhydrous ether (200 ml) was added 
1-naphthylmethanol (5.28 g, 33.4 mmol). The mixture was stirred at room 
temp. for 2 h and then concentrated in vacuo to a pale orange oil. This 
material was triturated with hexane and the resulting pale orange solid 
removed via filtration. The solid was washed several times with hexane and 
the combined filtrates from the washings passed through a short column of 
Florisil. Concentration in vacuo of the eluent afforded the bromide as a 
pale yellow solid. 
EXAMPLE 13 
L-Cysteinyl-4-(1-naphthyl)methyl isonipecotic acid ethyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 4, 
utilizing N-t-butoxycarbonyl isonipecotic acid ethyl ester and alkylating 
with 1-(bromomethyl) naphthalene and lithium diisopropylamide as the base 
in Step 2. The ethyl ester trifluoroacetic acid salt was obtained as a 
white fluffy solid. 
Anal. Calc'd for C.sub.22 H.sub.28 N.sub.2 O.sub.3 S 1.05 CF.sub.3 CO.sub.2 
H 0.25 H.sub.2 O: C, 55.16; H, 5.68; N, 5.34. Found: C, 55.13; H, 5.72; N, 
5.20. 
EXAMPLE 14 
L-Cysteinyl-4-(1-naphthyl)methyl isonipecotic acid benzyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 4, 
utilizing N-t-butoxycarbonyl isonipecotic acid benzyl ester and alkylating 
with 1-(bromomethyl) naphthalene and lithium diisopropylamide as the base 
in Step 2. The benzyl ester trifluoroacetic acid salt was obtained as a 
white fluffy solid. 
Anal. Calc'd for C.sub.27 H.sub.30 N.sub.2 O.sub.3 S 1.30 CF.sub.3 CO.sub.2 
H: C, 58.20; H, 5.16; N, 4.59. Found: C, 58.25; H, 5.18; N, 4.94. 
EXAMPLE 15 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid 2-pyridylmethyl ester 
trifluoroacetic acid salt 
Step 1: Preparation of N-t-butoxycarbonyl-4-(2-methylbenzyl) isonipecotic 
acid 2-pyridylmethyl ester 
To a solution of N-t-butoxycarbonyl-4-(2-methylbenzyl) isonipecotic acid 
(666 mg, 2.0 mmol) in dry CH.sub.2 Cl.sub.2 (15 ml) was added 
1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (421 mg. 2.2 
mmol). After stirring 15 min., 2-pyridine carbinol (0.21 ml, 2.2 mmol) and 
4-dimethylaminopyridine (244 mg, 2.0 mmol) were added and the reaction 
mixture stirred at room temp. overnight. The reaction mixture was then 
adsorbed directly onto a small amount of silica and chromatographed with 
30% EtOAc/hexane as eluent. The appropriate fractions were combined and 
concentrated in vacuo to afford the product as a colorless gum. 
Step 2: Preparation of 4-(2-methylbenzyl)isonipecotic acid 2-pyridylmethyl 
ester bis HCl salt 
N-t-butoxycarbonyl-4-(2-methylbenzyl)isonipecotic acid 2-pyridylmethyl 
ester was deprotected as described above in Example 1, Step 6 to afford 
the product as a white hygroscopic solid. 
Step 3: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-(2-methylbenzyl)isonipecotic 
acid 2-pyridylmethyl ester 
4-(2-methylbenzyl)isonipecotic acid 2-pyridylmethyl ester bis HCl salt was 
coupled to N-t-butoxycarbonyl-S-trityl-L-Cysteine utilizing the procedure 
described in Example 1, Step 7 to afford the product as a white foam. 
Step 4: Preparation of L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid 
2-pyridylmethyl ester bis trifluoroacetic acid salt 
N-t-butoxycarbonyl-S-trityl-L-Cysteine 4-(2-methylbenzyl)isonipecotic acid 
2-pyridylmethyl ester was deprotected and purified as described in Example 
1, Step 8 to afford the product as a white fluffy solid. 
Anal. Calc'd for C.sub.23 H.sub.29 N.sub.3 O.sub.3 S 2.80 CF.sub.3 CO.sub.2 
H 0.20 H.sub.2 O: C, 45.78; H, 4.33; N, 5.60. Found: C, 45.78; H, 4.33; N, 
5.87. 
EXAMPLE 15(a). 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid 3-pyridylmethyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 15, 
substituting 3-pyridine carbinol. The methyl ester bis trifluoroacetic 
acid salt was obtained. 
Anal. Calc'd for C.sub.23 H.sub.29 N.sub.3 O.sub.3 S 2.35 CF.sub.3 CO.sub.2 
H 0.40 H.sub.2 O: C, 47.35; H, 4.61; N, 5.98. Found: C, 47.33; H, 4.63; N, 
6.06. 
EXAMPLE 15(b) 
L-Cysteinyl-4-(2-methylbenzyl)isonipecotic acid 4-pyridylmethyl ester 
trifluoroacetic acid salt 
The titled compounds were prepared according to the methods of Example 15, 
substituting 4-pyridine carbinol. The methyl ester bis trifluoroacetic 
acid salt was obtained. 
Anal. Calc'd for C.sub.23 H.sub.29 N.sub.3 O.sub.3 S 2.10 CF.sub.3 CO.sub.2 
H 1.70 H.sub.2 O: C, 46.83; H, 4.98; N, 6.02. Found: C, 46.83; H, 5.02; N, 
6.03. 
EXAMPLE 16 
L-Cysteinyl-4-benzyl-4-piperidinol trifluoroacetic acid salt 
Step 1: Preparation of N-benzyl-4-benzyl-4-piperidinol 
To a solution of benzyl magnesium chloride (40 ml of 2.0 M soln. in THF, 80 
mmol)in THF (80 ml) was added 1-benzyl-4-piperidinone (7.4 ml, 40 mmol) 
over 7 min. and stirred overnight. The o reaction mixture was poured over 
ice and extracted with ether (2.times.). The combined ether extracts were 
washed with brine, dried (Na.sub.2 SO.sub.4), and concentrated in vacuo to 
a pale green syrup. This material was chromatographed on silica with 
50-60% EtOAc/hexane as eluent. The appropriate fractions were combined and 
concentrated in vacuo to afford the product as an off white solid. 
Step 2: Preparation of 4-Benzyl-4-piperidinol 
A mixture of N-benzyl-4-benzyl-4-piperidinol (2.0 g, 7.1 mmol) and 10% 
palladium on charcoal catalyst (0.5 g) in absolute ethanol (100 ml), was 
stirred vigorously at 40.degree. C. under a balloon of hydrogen for 5 h. 
The reaction mixture was then filtered through a pad of Celite and the 
filtrate concentrated in vacuo to a grayish solid. This material was 
dissolved in methanol and filtered a second time through Celite and the 
filtrate concentrated in vacuo to the product, a white solid. 
Step 3: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-benzyl-4-piperidinol 
The coupling procedure as described above in Example 1, Step 7 was 
utilized, with the amendment that no amine base was added, to afford the 
product as a white foam. 
Step 4: Preparation of L-Cysteinyl-4-benzyl-4-piperidinol 
Cysteine deprotection as described above in Example 1, Step 8 afforded the 
product as a white solid. 
Anal. Calc'd for C.sub.15 H.sub.22 N.sub.2 O.sub.2 S 1.30 CF.sub.3 CO.sub.2 
H 0.05 H.sub.2 O: C, 47.66; H, 5.32; N, 6.32. Found: C, 47.68; H, 5.32; N, 
6.32. 
EXAMPLE 17 
L-Cysteinyl-4-acetoxy-4-benzylpiperidine trifluoroacetic acid salt 
Step 1: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteine-4-acetoxy-4-benzylpiperidine 
To a solution of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl4-benzyl-4-piperidinol (100 mg, 
0.16 mmol) in dry pyridine (2 ml), was added 4-dimethylaminopyridine (25 
mg, 0.20 mmol) and acetic anhydride (0.030 ml, 0.32 mmol). The solution 
was heated to 50.degree. C. (oil bath temp.) for 2 days and then allowed 
to cool to room temp. The reaction mixture was concentrated in vacuo and 
the residue partitioned between EtOAc and brine. The EtOAc layer was dried 
(MgSO.sub.4) and concentrated in vacuo to a brown oil. This material was 
purified by column chromatography on silica with 18-20% EtOAc/hexane as 
eluent. The appropriate fractions were combined and concentrated in vacuo 
to afford the product as a glassy solid. 
Step 2: Preparation of L-Cysteinyl-4-acetoxy-4-benzylpiperidine 
Cysteine deprotection as described above in Example 1, Step 8 afforded the 
product as a white fluffy solid. 
Anal. Calc'd for C.sub.17 H.sub.24 N.sub.2 O.sub.3 S 1.15 CF.sub.3 CO.sub.2 
H 0.40 H.sub.2 O: C, 48.73; H, 5.52; N, 5.89. Found: C, 48.75; H, 5.48; N, 
6.16. 
EXAMPLE 18 
L-Cysteinyl-4-cyano-4-phenylpiperidine trifluoroacetic acid salt 
Step 1: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-cyano-4-phenylpiperidine 
The coupling procedure as described above in Example 1, Step 7 was 
utilized, with commercially available 4-phenyl-4-cyano-piperidine 
hydrochloride salt, to afford the product as a white foam. 
Step 2: Preparation of L-Cysteinyl-4-cyano 4-phenylpiperidine 
Cysteine deprotection as described above in Example 1, Step 8 afforded the 
product as a white solid. 
Anal. Calc'd for C.sub.15 H.sub.19 N.sub.3 OS 1.20 CF.sub.3 CO.sub.2 H 0.15 
H.sub.2 O: C, 48.72; H, 4.82; N, 9.80. Found: C, 48.78; H, 4.81; N, 9.75. 
EXAMPLE 19 
L-Cysteinyl-4-acetyl-4-phenylpiperidine trifluoroacetic acid salt 
Step 1: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-acetyl-4-phenylpiperidine 
The coupling procedure as described above in Example 1, Step 7 was 
utilized, with commercially available 4-acetyl-4-phenyl-piperidine 
hydrochloride salt, to afford the product as a white foam. 
Step 2: Preparation of L-Cysteinyl-4-acetyl-4-phenylpiperidine 
Cysteine deprotection as described above in Example 1, Step 8 afforded the 
product as a white solid. 
Anal. Calc'd for C.sub.16 H.sub.22 N.sub.2 O.sub.2 S 1.45 CF.sub.3 CO.sub.2 
H: C, 48.12; H, 5.01; N, 5.94. Found: C, 48.02; H, 5.06; N, 5.96. 
EXAMPLE 20 
L-Cysteinyl-4-methoxymethyl-4-(2-methylbenzyl)piperidine trifluoroacetic 
acid salt 
Step 2: Preparation of 
N-t-Butoxycarbonyl-4-hydroxymethyl-4-(2-methylbenzyl)piperidine 
To a suspension of lithium aluminum hydride (0.32 g, 8.4 L s mmol) in 
anhydrous ether (50 ml) was added a solution of 4-(2-methylbenzyl) 
N-t-butoxycarbonyl isonipecotic acid benzyl ester (3.0 g, 7.1 mmol) in 
anhydrous ether (25 ml) over 15 min. The resulting mixture was heated 
gently at reflux for 1 h. The reaction mixture was then quenched with the 
slow and successive addition of H.sub.2 O (0.32 ml), 15% aqueous NaOH, and 
H.sub.2 O (0.96 ml). After sirring for 30 min., the mixture was filtered 
through Celite and the filtrate washed with brine, dried (MgSO.sub.4), and 
concentrated in vacuo to a colorless syrup. Purification by column 
chromatography on silica with 25%-50% EtOAc/hexane as eluent afforded the 
product as a colorless gum. This material was recrystallized from EtOAc 
and hexane to afford a white solid. m.p. 104.degree.-106.degree. C. 
Step 2: Preparation of 
N-t-Butoxycarbonyl-4-methoxymethyl-4-(2-methylbenzyl)piperidine 
To a 0.degree. C. suspension of sodium hydride (19 mg, 0.80 mmol) in 1.5 ml 
of THF, was added a solution of 
N-t-butoxycarbonyl-4-hydroxymethyl-4-(2-methylbenzyl)piperidine (200 mg, 
0.63 mmol) in 1 ml THF. The mixture was allowed to warm to room temp. To 
this suspension was added 0.35 ml of anhydrous DMSO and the mixture was 
heated to 60.degree. C. and stirred 5 h until the solution was almost 
homogeneous. The reaction mixture was allowed to cool to room temp. and to 
this solution was added methyl iodide (0.070 ml, 1.12 mmol). The resulting 
heterogeneous mixture was stirred at room temp. overnight. The reaction 
mixture was treated with 10% aqueous citric acid and extracted with ether 
(3.times.). The combined ether extracts were washed successively with 
saturated aqueous NaHCO.sub.3 and brine, dried (MgSO.sub.4), and 
concentrated in vacuo to a yellow gum. Purification by column 
chromatography on silica with 9% EtOAc/hexane as eluent afforded the 
product as a colorless gum. 
Step 2: Preparation of 4-Methoxymethyl-4-(2-methylbenzyl)-piperidine HCl 
salt 
N-t-Butoxycarbonyl-4-methoxymethyl-4-(2-methylbenzyl) piperidine was 
deprotected as described above in Example 1, Step 6 to afford the product 
as a white solid. 
Step 3: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-methoxymethyl-4-(2-methylbenzyl) 
piperidine 
The coupling procedure as described above in Example 1, Step 7 was utilized 
to afford the product as a white foam. 
Step 4: Preparation of 
L-Cysteinyl-4-methoxymethyl-4-(2-methylbenzyl)piperidine 
Cysteine deprotection as described above in Example 1, Step 8 afforded the 
product as a white solid. 
Anal. Calc'd for C.sub.18 H.sub.28 N.sub.2 O.sub.2 S 1.25 CF.sub.3 CO.sub.2 
H 0.20 H.sub.2 O: C, 51.02; H, 6.19; N, 5.80. Found: C, 50.97; H, 6.19; N, 
6.04. 
EXAMPLE 21 
L-Cysteinyl-4-acetamido-4-(2-methylbenzyl)piperidine trifluoroacetic acid 
salt 
Step 1: Preparation of 
N-t-butoxycarbonyl-4-amino-4-(2-methylbenzyl)piperidine 
To a mixture of 4-(2-methylbenzyl) N-t-butoxycarbonyl isonipecotic acid 
(1.0 g, 3.0 mmol) in CH.sub.3 CN (20 ml) add diphenyl phosphoryl azide 
(0.99 g, 3.6 mmol) and triethylamine (0.50 ml, 3.6 mmol). After stirring 
at 55.degree. C. (oil bath temp.) concentrate the reaction in vacuo and 
partion the residue between EtOAc and saturated aqueous NaHCO.sub.3. The 
organic phase is washed with brine, dried (MgSO.sub.4), and concentrated 
in vacuo to afford the crude product. 
Step 2: Preparation of 
N-t-butoxycarbonyl-4-acetamido-4-(2-methylbenzyl)piperidine 
A mixture of N-t-butoxycarbonyl-4-amino-4-(2-methylbenzyl)piperidine (305 
mg, 1.0 mmol), acetic anhydride (0.38 ml, 4.0 mmol), and pyridine (0.1 ml, 
1.2 mmol) in CH.sub.2 Cl.sub.2 is stirred at room temp. overnight. Then 
concentrate the reaction mixture in vacuo and purify the residue by column 
chromatography on silica to afford the product. 
Step 3: Preparation of 4-Acetamido-4-(2-methylbenzyl)piperidine 
hydrochloride salt 
The N-t-butoxycarbonyl deprotection procedure as described above in Example 
1, Step 6 is utilized to afford the product. 
Step 4: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-acetamido-4-(2-methylbenzyl)pipe 
ridine 
The coupling procedure as described above in Example 1, Step 7 is utilized 
to afford the product. 
Step 5: Preparation of L-Cysteinyl-4-acetamido-4-(2-methylbenzyl)piperidine 
trifluoroacetic acid salt 
Cysteine deprotection as described above in Example 1, Step 8 affords the 
product. 
EXAMPLE 22 
L-Cysteinyl-4-methylsulfonamido-4-(2-methylbenzyl)piperidine 
trifluoroacetic acid salt 
Step 1: Preparation of 
N-t-butoxycarbonyl-4-methylsulfonamido-4-(2-methylbenzyl)piperidine 
A mixture of N-t-butoxycarbonyl-4-amino-4-(2-methylbenzyl)piperidine (305 
mg, 1.0 mmol), methane-sulfonyl chloride (0.31 ml, 4.0 mmol), and pyridine 
(0.1 ml, 1.2 mmol) in CH.sub.2 Cl.sub.2 (2 mL) is stirred at room temp. 
overnight. Then concentrate the reaction mixture in vacuo and purify the 
residue by column chromatography on silica to afford the product. 
Step 2: Preparation of 4-Methylsulfonamido-4-(2-methylbenzyl) piperidine 
hydrochloride salt 
The N-t-butoxycarbonyl deprotection procedure as described above in Example 
1, Step 6 is utilized to afford the product. 
Step 3: Preparation of 
N-t-butoxycarbonyl-S-trityl-L-Cysteinyl-4-methylsulfonamido-4-(2-methylben 
zyl)piperidine 
The coupling procedure as described above in Example 1, Step 7 is utilized 
to afford the product. 
Step 4: Preparation of 
L-Cysteinyl-4-methylsulfonamido-4-(2-methylbenzyl)piperidine 
trifluoroacetic acid salt 
Cysteine deprotection as described above in Example 1, Step 8 affords the 
product. 
EXAMPLE 23 
In vitro inhibition of ras farnesyl transferase 
Farnesyl-protein transferase (FTase) from bovine brain was chromatographed 
on DEAE-Sephacel (Pharmacia, 0-0.8 M NaCl gradient elution), N-octyl 
agarose (Sigma, 0-0.6 M NaCl gradient elution), and a mono Q HPLC column 
(Pharmacia, 0-0.3 M NaCl gradient). Ras-CVLS at 3.5 .mu.M, 0.25 .mu.M 
[.sup.3 H]FPP, and the indicated compounds were incubated with either a 
partially purified bovine enzyme preparation or a recombinant human enzyme 
preparation. The recombinant human enzyme was prepared as described in 
Omer, C. A., Kral, A. M., Diehl, R. E., Prendergast, G. C., Powers, S., 
Allen, C. M., Gibbs, J. B. and Kohl, N. E. (1993) Biochemistry 
32:5167-5176. The FTase data presented reflects the ability of the test 
compound to inhibit RAS farnesylation in vitro, as described in Pompliano, 
et al., Biochemistry 31:3800 (1992). 
In the above assay, the compounds, as listed on pages 6-8, demonstrated the 
ability to inhibit RAS farnesylation at a concentration of 10 .mu.M or 
less. For the preferred compounds, listed on pages 8 to 9, activity was 
exhibited at 2 .mu.M or less.