4-Methyl-1,2,4-triazol-3-yl heterocycle as an alternative to the 1-methylimidazol-5-yl moiety in the Farnesyltransferase inhibitor ZARNESTRA

Article abstract of DOI:10.1016/j.bmcl.2003.09.043

Replacement of the 1-methylimidazol-5-yl moiety in the farnesyltransferase inhibitor ZARNESTRA series by a 4-methyl-1,2,4-triazol-3-yl group gave us compounds with similar structure-activity relationship profiles showing that this triazole is potentially a good surrogate to imidazole for farnesyltransferase inhibition.

Full text of DOI:10.1016/j.bmcl.2003.09.043

Bioorganic & Medicinal Chemistry Letters 13 (2003) 4361–4364
4-Methyl-1,2,4-triazol-3-yl Heterocycle as an Alternative to the
1-Methylimidazol-5-yl Moiety in the Farnesyltransferase
TM
Inhibitor ZARNESTRA
Patrick Angibaud,a,* Ashis K. Saha,b,y Xavier Bourdrez,a David W. End,b Eddy Freyne,c
Patricia Lezouret,a Geert Mannens,d Laurence Mevellec,a Christophe Meyer,a
Isabelle Pilatte,a Virginie Poncelet,a Bruno Roux,a Gerda Smets,c,{ Jacky Van Dun,c
Marc Veneta,x and Walter Wouterse
aMedicinal Chemistry Department Johnson & Johnson Pharmaceutical Research & Development (J&JPRD),
Campus de Maigremont BP615, 27106 Val de Reuil, France
bOncology Drug Discovery, J&JPRD L.L.C. Welsh and McKean Roads, Spring-House, PA 19477-0776, USA
cOncology Drug Discovery, J&JPRD, Turnhoutseweg 30, B-2340, Belgium
dPreclinical Pharmacokinetics, J&JPRD, Turnhoutseweg 30, B-2340, Belgium
eDrug Evaluation, J&JPRD, Turnhoutseweg 30, B-2340, Belgium
Received 17 July 2003; revised 15 September 2003; accepted 16 September 2003
TM
Abstract—Replacement of the 1-methylimidazol-5-yl moiety in the farnesyltransferase inhibitor ZARNESTRA series by a 4-
methyl-1,2,4-triazol-3-yl group gave us compounds with similar structure–activity relationship profiles showing that this triazole is
potentially a good surrogate to imidazole for farnesyltransferase inhibition.
# 2003 Elsevier Ltd. All rights reserved.
The past decade has seen a growing interest in Farnesyl
Protein Transferase (FPT), an enzyme which catalyses a
key step in the anchoring of Ras protein to the cell
membrane. Once attached to the cell membrane Ras is
acting as a signal transducer from external growth fac-
tors to the cell nucleus. Mutated forms of Ras are found
in approximately 30% of human cancers1,2 providing a
continuous signal for the transformation and uncon-
trolled growth of malignant tumor cells.3ꢀ11 Therefore it
was hypothesized that inhibitors of farnesyl protein
transferase (FTI’s) would be important and novel can-
cer therapeutic drugs. Several FTI’s are currently
undergoing clinical trials. Data from these trials as well
as from recent biological research has shown that the
antitumor activity of the class is not only related to Ras
functioning. Rather it also involves other farnesylated
proteins such as RhoB, and centromere associated pro-
teins or modulation of transcription events.11ꢀ21
One of the first FTI’s to enter clinical trials,
TM
R11577722,23 1 (ZARNESTRA ) is a 4-phenylquinoli-
none bearing an asymmetric carbon atom substituted by
the 1-methylimidazol-5-yl moiety (Fig. 1). Earlier stud-
ies have shown that this imidazole is uniquely active
conferring FPT inhibitory activity to analogues of
R115777.24ꢀ26 Furthermore, the substitutions intro-
duced on the imidazole heterocycle either in position-2
or -4 led to a dramatic decrease in potency.25,26
*Corresponding author. Tel.: +33-2-3261-7457; fax: +33-2-3261-
7298; e-mail: pangibau@prdfr.jnj.com
Herein, we describe the synthesis and inhibitory profile
of
ocyclyl)methyl]-4-(3-chlorophenyl)-1-methyl-2(1H)-qui-
nolinones, evaluating the replacement of either the C-2
or/and the C-4 imidazole carbon atoms by nitrogen in
order to identify imidazole surrogates.27
yCurrent address: Viropharma Inc., 405 Eagleview Blvd, Exton, PA
19341, USA.
a
series of 6-[amino(4-chlorophenyl)(heter-
{Current address: Centocor, Medical Affairs, Einsteinweg 92, 2333 CD
Leiden, The Netherlands.
xCurrent address: SERIPHARM, rue Democrite 72000 Le Mans,
France.
0960-894X/$ - see front matter # 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmcl.2003.09.043

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P. Angibaud et al. / Bioorg. Med. Chem. Lett. 13 (2003) 4361–4364
Taking the hydroxy analogue 2 of R115777 as a refer-
ence compound24 (Fig. 1) we first replaced the C-4 by a
nitrogen (Scheme 1).
further transformed into the amino 12 after chlorination
followed by substitution of the chlorine by ammonia.
Further introduction of a nitrogen on this five mem-
bered ring led us to prepare 1-methyltetrazol-5-yl deri-
vatives such as 15 (Scheme 2). Conversion of the nitrile
4 to the tetrazolyl derivative 13 was achieved by reacting
4 with sodium azide. Alkylation of 13 by methyliodide
gave 14 and the hydroxy substituent was introduced by
oxidation to provide 15.
Nitrile 4 was obtained by reacting the ketone 324 with
tosylmethylisocyanide and was then hydrolyzed into the
acid 5. Coupling 5 with 4-methylthiosemicarbazide gave
6 which was cyclized under basic conditions into 7.
Subsequent alkylation of the sulfur gave 8. Finally,
reductive removal of the methylsulfide provided us with
our first analogue 9. Deprotonation and oxidation of 9
enabled us to introduce the hydroxy moiety which was
These compounds were evaluated for inhibition of FPT
in vitro and compared to 1 and 2 (Table 1).
Triazoles 10 and 12 showed the same potency range for
enzymatic inhibition as the imidazole compounds 1 and
2 whereas the tetrazole 15 proved to be inactive at a 0.1
mM concentration. For the latter, modification of the
heterocycle basicity probably explains the drastic loss in
potency concomitant to a loss of zinc binding proper-
ties. Therefore the tetrazoles were not further studied.
Figure 1. Structure of R115777 1 and its hydroxy analogue 2 (racemic
form).
Two other triazole examples 16 and 21 were prepared
and compared to the equivalent imidazoles 23 and 2424
(Table 1).
Deprotonation of 9 (Scheme 3) and subsequent alkyl-
ation of the generated anion gave 16 with a moderate
yield (Scheme 3).
The N-demethylated quinolinone analogue of 10 was
obtained as described in Scheme 4 starting from the 2-
chloroquinoline 17.29 The chlorine moiety was sub-
Scheme 2. Reagents and conditions: (a) NaN3, NH4Cl, DMF,
120 ꢁC, 24 h, 88%; (b) CH3I, K2CO3, CH3CN, 80 ꢁC, 2 h, 25%; (c) t-
BuOK, DME, air bubbling, 5 ꢁC–rt, 6 h, 24%.
Scheme 1. Reagents and conditions: (a) TsCH2NC, t-BuOK, DME,
DMF, t-BuOH, rt 3 h, 74%; (b) AcOH, H2SO4, 110 ꢁC, 3 h, 92%; (c)
MeNHC(S)NHNH2, DIEA, HOBT, THF, rt, 18 h, 50%; (d) MeONa,
MeOH, 60 ꢁC, 3 h; then (e) CH3I, rt, 0.5 h, 84%; (f) Ni–Raney, EtOH,
80 ꢁC, 18 h, 66%; (g) t-BuOK, DME, air bubbling, rt, 1 h, 77%; (h)
SOCl2, rt, 4 h; (i) NH3/i-PrOH, THF, 5 ꢁC–rt, 1 h, 57%.
Scheme 3. Reagents and conditions: (a) CH3I, t-BuOK, DME, rt, 0.5
h, 54%.

P. Angibaud et al. / Bioorg. Med. Chem. Lett. 13 (2003) 4361–4364
4363
Table 1. FPT inhibition comparison between the tetrazole, triazole and the imidazole series
Compd
Heterocycle
R1
R2
FPT (enz) IC50, nMa
Cell proliferation
IC50, nMb
2
1
A
A
B
B
C
A
B
A
B
A
B
OH
NH2
OH
NH2
OH
H
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
H
1.7
0.9
6
1.3
12
1.7
151
24
nt
174
80
58
nt
400
nt
10
12
15
22c
9
23c
16
24c
21
0% inh. @ 0.1mM
3
1
4
5
4
26
H
CH3
CH3
OH
OH
H
nt, not tested.
aThe concentration required for a 50% reduction of the FPT-catalyzed incorporation of [3H]-farnesylpyrophosphate into a biotinylated lamin B
peptide.
bSee ref 28.
cSynthesis described in ref 24.
Table 2. Comparison of in vitro and in vivo results for compounds
R115777 and 9
Compd
Metabolizationa (%)
In vivob % inhib
R115777
9
66
77
37
45
aPercentage of parent drug remaining after 120 min incubation with
human liver microsomes.28
bIn vivo screening at 25 mg/kg in mice inoculated with T24H-ras NIH
3T3 cells, percentage of tumor weight inhibition.28 Compounds were
administered orally once daily starting 2 days after tumor inoculation
and tumor growth inhibition was measured 17 days after
administration.
With the exception of the last entry (compound 21)
where a slight decrease of activity was observed the
triazolyl quinolinones showed the same enzymatic
activity as the corresponding imidazoles, but changing
imidazole to triazole induced a decrease in anti-
proliferative activity in cell based assays (10, 12 vs 2, 1,
respectively). Compound 9, being one of the most che-
mically accessible member of this series, it was chosen as
a first example to draw a preliminary pharmacological
profile of triazole series (Table 2).
Scheme 4. Reagents and conditions: (a) MeONa, MeOH, 80 ꢁC, 16 h,
62% two steps; (b) 4-methyl-1,2,4-triazole-3-thione, n-BuLi, THF,
ꢀ70 to 0 ꢁC, 2.5 h, 35%; (c) NaNO2, HNO3, THF, H2O, rt, 0.25 h,
61%; (d) HCl 6 N, 100 ꢁC, 48 h, 73%.
Although both changes (imidazole to triazole and NH2
into H) induced a decreased activity in cell based assays,
and being a racemic mixture, triazole 9 proved to have
similar in vivo potency as R115777 in this preliminary
experiment.
stituted by a methoxy group easier to remove after-
wards. The triazole heterocycle was then introduced
directly by addition of the 5-lithio-4-methyl-1,2,4-tri-
azole-3-thione onto ketone 18 followed by removal of
the thiol (Scheme 4). This procedure is more straight-
forward than the triazole ring construction depicted in
Scheme 1. Then the 2-methoxy group was cleaved in
acidic media to provide 21.
In vitro results have shown that 4-methyl-1,2,4-triazol-
3-yl moiety can potentially replace 1-methylimidazol-5-
yl heterocycle while designing FTI’s. Preliminary in vivo
results have encouraged us to further compare solubil-
ity, metabolism, pharmacokinetics and in vivo profiles
TM
of such triazolyl inhibitors with ZARNESTRA .

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P. Angibaud et al. / Bioorg. Med. Chem. Lett. 13 (2003) 4361–4364
17. Gibbs, R. A.; Zahn, T. J.; Sebolt-Leopold, J. S. Curr.
Med. Chem. 2001, 8, 1437.
Acknowledgements
18. Karp, J. E.; Kaufmann, S. H.; Adjei, A. A.; Lancet, J. E.;
Wright, J. J.; End, D. W. Curr. Opin. Oncol. 2001, 13, 470.
19. Tamanoi, F.; Kato-Stankiewicz, J.; Jiang, C.; Machado,
I.; Thapar, N. J. Cell. Biochem. 2001, 37, 64.
The authors are grateful to G. Goussot and J. M.
Argoullon for chromatography and analytical support.
20. Haluska, P.; Dy, G. K.; Adjei, A. A. Eur. J. Cancer 2002,
38, 1685.
References and Notes
21. Ohkanda, J.; Knowles, D. B.; Blaskovich, M. A.; Sebti,
S. D.; Hamilton, A. D. Cur. Top. Med. Chem. 2002, 2, 303.
22. End, D. W.; Smets, G.; Todd, A. V.; Applegate, T. L.;
Fuery, C. J.; Angibaud, P.; Venet, M.; Sanz, G.; Poignet, H.;
Skrzat, S.; Devine, A.; Wouters, W.; Bowden, C. Cancer Res.
2001, 61, 131.
1. Rodenhuis, S. Semin. Cancer Biol. 1992, 3, 241.
2. Bos, J. L. Cancer Res. 1989, 49, 4682.
3. Barbacid, M. Ann. Rev. Biochem. 1987, 56, 779.
4. Casey, P. J.; Solski, P. A.; Der, C. J.; Buss, J. E. Proc. Natl.
Acad. Sci. U.S.A. 1989, 86, 8323.
5. Kato, K.; Cox, A. D.; Hisaka, M. M.; Graham, S. M.;
Buss, J. E.; Der, C. J. Proc. Natl. Acad. Sci. U.S.A. 1992, 89,
6403.
23. Norman, P. Curr. Opin. Investing. Drugs 2002, 3, 313.
24. Venet, M. G.; Angibaud, P. R.; Muller, P.; Sanz, G. C.
WO patent 97/21701, 1997.
6. Der, C. J.; Cox, A. D. Cancer Cells 1991, 3, 331.
7. Seabra, M. C.; Reiss, Y.; Casey, P. L.; Brown, M. S.;
Goldstein, J. L. Cell 1991, 65, 429.
8. Rowinsky, E. K.; Windle, J. J.; Von Hoff, D. D. J. Clin.
Oncol. 1999, 17, 3631.
9. Rowinsky, E. K.; Patnaik, A. Emerg. Drugs 2000, 5, 161.
10. End, D. W. Invest. New Drugs 1999, 17, 241.
11. Johnston, S. Lancet Oncol. 2001, 2, 18.
25. Venet, M. Abstract of Papers, 222nd National Meeting of
the American Chemical Society, Chicago, IL, Aug. 26–30,
2001; American Chemical Society: Washington, DC, 2001;
69BUZP.
26. Venet, M.; End, D. W.; Angibaud, P. Cur. Top. Med.
Chem. 2003, 3, 1095.
27. Angibaud, P. R.; Venet, M. G.; Saha, A. K.; Mevellec, L.
A. WO patent 02/24683, 2002.
12. Lebowitz, P. F.; Casey, P. J.; Prendergast, G. C.; Thissen,
J. A. J. Biol. Chem. 1997, 272, 15591.
13. Feldkamp, M. M.; Lau, N.; Rak, J.; Kerbel, R. S.; Guha,
A. Int. J. Cancer 1999, 81, 118.
14. Ashar, H. R.; James, L.; Gray, K.; Carr, D.; Black, S.;
Armstrong, L.; Bishop, W. R.; Kirschmeier, P. J. Biol. Chem.
2000, 275, 30451.
15. Adnane, J.; Bizouarn, F. A.; Chen, Z.; Ohkanda, J.;
Hamilton, A. D.; Munoz-Antonia, T.; Sebti, S. M. Oncogene
2000, 19, 5525.
28. Angibaud, P.; Bourdrez, X.; Devine, A.; End, D. W.;
Freyne, E.; Ligny, Y.; Muller, P.; Mannens, G.; Pilatte, I.;
Poncelet, V.; Skrzat, S.; Smets, G.; Van Dun, J.; Van
Remoortere, P.; Venet, M.; Wouters, W. Bioorg. Med. Chem.
Lett. 2003, 13, 1543.
29. Angibaud, P.; Bourdrez, X.; End, D. W.; Freyne, E.;
Janicot, M.; Lezouret, P.; Ligny, Y.; Mannens, G.; Damsch,
S.; Mevellec, L.; Meyer, C.; Muller, P.; Pilatte, I.; Poncelet, V.;
Roux, B.; Smets, G.; Van Dun, J.; Van Remoortere, P.; Venet,
M.; Wouters, W. Bioorg. Med. Chem. Lett. 2003, 13, in press.
doi:10.1016/j.bmcl.2003.08.080.
16. Gibbs, R. A. Curr. Opin. Drug Discov. Dev. 2000, 3, 585.