J. Med. Chem. 1991,34,1545-1552
1545
(Benzoylpheny1)piperidines: A New Class of Immunomodulators Franqois D. Bellamy,**tJean B. Chazan,f Pierre Dodey? Patrick Dutartre? Khan Ou,’ Marc Pascal,i and Jacques Robin’ Laboratoires Fournier Research Center, 50 rue de Dijon, 21121 Daix, France. Received February 21, 19!W A series of (benzoylpheny1)piperidmeshas been synthesized and evaluated for activity as immunomodulabrs. Several of these compounds show good activity in primary screening on the basis of the lymphocytes mitogenic response to Con A, PHA, and PWM. A chloro group in position 4 of the benzoyl moiety as well as an amino group (or a carbamate derivative) para to the piperidine nucleus seems to be essential for activity. The depicted compounds may be considered as the first examples of a new series of immunomodulators.
The clinical need for therapeutic agents able to restore a normal immune response in immunocompromised patients (primary and acquired immunodeficiency,recurrent viral infections, autoimmune diseases, cancer) has led to the discovery of a number of substances collectively defined as immunomodulators. The word has been coined to emphasize the phase variation of most of these drugs, which may enhance or suppress the immune response according to their mode of adminstration.14 Most of them are bacterial preparations or peptide hormones; only a few are synthetic, low molecular weight molecules.‘ As exemplified by the work performed with thymic hormones, one promising issue is to discover compounds acting on T lymphocytes either by enhancing T cell mediated activation or by favoring T cell differentiati~n.~ In this paper, we describe the synthesis and T cell immunomodulating properties of a series of (benzoylpheny1)piperidines (Table I) exemplified by structure I and structurally unrelated to other known immunomodulators.
chlorine through diazotization with isoamyl nitrite,’ followed by treatment with CuC12 led to 45. Selective displacement of the doubly activated chloro group and subsequent reduction to the nitro substituent then afforded the desired compound 12. Scheme I11 describes the synthetic route used for preparation of the 3-monosubsubstituted derivatives. Again, with 6-chloro-3-nitrobenzoic acid as the starting material, the chlorine atom was first replaced by the piperidine unit, and the corresponding acid chloride 48 was then treated with the appropriate organocadmium reagents 49. A final reduction (Fe/HCl) of the resulting nitrobenzophenones 50 gave the expected products (13,14, and 15).
Aromatic Substitution of Ring B (Substituent R4; Compounds 16-25). As a consequence of the synthetic approaches chosen, all compounds first synthesized bore an NH2 group para to the piperidine ring. As it became desirable to investigate the influence of thisR4substituent on the biological activity, modifications were performed on the NH2 group as depicted in Scheme IV. These inR’.R2,R3 = H.Cl,Br,F.0CH3 volved classical transformations which do not require R‘ \ \ further comment. R4 = H,Cl,N,R’,R’ 0 Compounds in which the NH2group had been replaced by hydrogen were obtained by a more straightforward Rs,R6 = H,CH,,C~HS,~BU,~BUS~,CH~P~,OH route and with better yields by simply substituting the fluor0 group of substituted 2-fluorobenzophenones (51) by I the piperidine unit. Chemistry Modification of the Piperidine Ring (Substituents R5,R6; Compounds 26-35). A range of suitably substiAromatic Substitution of Ring A (SubstituentsR’, tuted piperidines was also investigated. Most of the R2,R8Compounds 1-15). For all compounds, except the starting materials were commercial and only a few had to 2- and 3-monosubstituted examples, the benzophenone be prepared. Those piperidines bearing an ethyl or a framework was constructed by F r i e d e l - C r h reaction of tert-butyl group (52 and 53, respectively) at C-4 were o b 6-chloro-3-nitrobenzoyl chloride (37) with a suitably subtained by catalytic hydrogenation of the corresponding stituted benzene 38 (Scheme I). The piperidine subunit pyridines by using slightly modified standard proceduress 40 was then introduced by nucleophilic displacement of (see Experimental Section). Finally, the Cbutylpiperidine chlorine. Subsequent reduction of the nitro group of 41 55 was prepared in two steps from the commercially with either Fe or SnC12in acidic medium afforded the final available N-benzyl-4-piperidone (54) according to Scheme compounds. However, because of the directional control V.10 of substitution in the Friedel-Crafts reaction, this route was not applicable for the 2- and the 3-monosubstituted compounds and alternative synthetic schemes had to be (1) Leclerc, C.; Juy, D.; Chedid L. Cell. Immunol. 1979,42,336. developed. According to a recent patent: 2-halo deriva(2) Cattney, J.; Bruin, J.; Lewis, A. J. Agents Actions 1980, IO,48. tives of 2-amino-5-nihbenzophenonemay be obtained by (3) Cattney, J.; Bruin, J.; Lewis, A. J. Agents Actions 1980, 10, Friedel-Crafta reaction of a 2-halobenzoyl chloride with 378. 4-nitrobenzalinilides (Scheme 11). In our hands, this re(4) St. Gerogiev, V. Trends Pharmacol. Sci. 1988,9,446. action conducted between 42 and 43 was successful, but ( 5 ) Goldstein, A. L.; Guha, A.; Zatz, M. M.; Hardy, M.A.; White, the adduct 44 was obtained in only moderate and nonreA. Proc. Not. Acad. Sci. U.S.A. 1972,69,1800. (6) Mouzin, G.; Causae, H.; Autin, J. M. Fr. Patent 2,476,070,1981. producible yields. Replacement of the amino group by
aQ:
(7) Doyle, M. P.; Siegfried, B.; Dellaria J. F., Jr. J . Org. Chem.
Chemistry Department. *Present address: I.T.E.R.G., 10 A rue de la Paix, 75002 Paris. 8 Immunology Department. Preaent address: Sanofi-Recherche,9 rue du F’r6s. S. Allende, 94256 Gentilly. 0022-2623/91/1834-1545$02.M)/0
1977,42,2426.
(8) Dauben, W. G.; Tillea, H.J . Org. Chem. 1950, 15, 785. (9) Wawzanek, W.; Nelson M. F., Jr.; Thelen, P. J. J. Am. Chem.
SOC.1952, 74, 2894. (10) Prasad, K. B.; Al-Jallo, H.N.;Al-Dulaimi, K. S. J. Chem. Soc. C. 1969,16,2134. Q 1991 American Chemical Society
Bellamy et al.
1546 Journal of Medicinal Chemistry, 1991, Vol. 34, No. 5
Scheme I
COZH
PCI,
R'
c1
a R3
36
0
c1
40-91%
41
u-
O QR5
R6R5
_ 1-11 _
R6
16: R'=4-C1, R2=R3=R5=H,R6=4-CH3 -
Scheme I1
\
\
CI
0
-
c1
\
\
90%
CI
Pip
0
46
45 -
Scheme I11 COZH H*3
1 Pip CH3
PC1,
-
L
c1
70%
55%
47
42
-
()&
20-40%
Fe.HC1
RI
NH2 I
50%
0
Pip
13,rs,Is
50
Results and Discussion 1. Proliferative Response to Mitogens. The biological activity of the (benzoylpheny1)piperidinesdescribed herein was first determined by the ability of these compounds to stimulate the proliferative response of spleen cells to mitogens, as this is the most commonly studied function of such cells. Augmentation of lymphoproliferative responses to mitogens has been consistently observed with such drugs as is~prinosine'~ and 2,2'-[ethylenebis(11) Renoux, G. Immunomodulators; Mased Eds;Prous Science: Barcelona, 1986; p 45. (12) Miller, K.Immunobiology 1983, 165, 132.
0
Pip
(dithio)]bisethanol (ADA 202-718).14 After having confirmed the lack of intrinsic mitogenic effect of our test compounds in the absence of lectin, the proliferative potential of each product was evaluated over the concentration range of 5 to 80 pg/mL. The results in Table I1 list the values obtained for each compound at their optimal stimulating concentration. (13) Ikehara, S.;Hadden, J. W.; Good, R. A.; Lunzer, D. G.; Pahwa, R. N. Thymus 1981,3, 87. (14) Wieser, G.; Wiegele, J.; Troppmair, J.; Leter, E.;Ganzinger, U.; Margreiter, R.; Huber, C. Int. J. Immunopharmacol. 1986,8,
831.
Journal of Medicinal Chemistry, 1991, Vol. 34, No.5 1547
(Benzoylpheny1)piperidinesas Immunomodulators Table I. (Benzoylpheny1)piperidinesSynthesized no. R' R2 R3 1 H H H H 2 H 4-CH3 3 H 4-F H H H 4 4-Br H H 5 4-C1 H H 6 4-OCH3 4-CH3 H 2-CH3 7 4-OCH3 H 8 3-OCH3 4-Cl 3-ci 9 H 4-C1 10 2x1 H 11 4-CH3 3-CH3 5-CH3 12 2x1 H H H 13 3-C1 H 14 H H 3-CH3 H H 3-CF3 15 4-C1 16 H H 4-C1 H 17 H 4-C1 18 H H H 4-OCH3 19 H H H H 20 4-C1 21 H H 441 22 H H 4-C1 23 H H H 4-C1 24 H 441 25 H H H H 4-C1 26 H 4-C1 H 27 H 4-C1 28 H H H 4-C1 29 H 441 H 30 H H 4-C1 31 H 441 32 H H H 441 33 H 441 H 34 35 4-C1 H H
RS
Re
4-CH2 4-CH; 4-CH3 4-CH2 4-CH; 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH3 4-CH2 4-CH; 4-CH3 4-CH3 4-CH3 3-CH3 H 3-CH3 2-CH3 4-CH3 4-t-BU 4-CzH5 4-n-Bu 4-CHzPh 4-Ph 4-OH
H H H H H H H H H H H H H H H H H H H H H H H H H H H H 5-CH3 H H H H H H
R4 NH,
H H H NHCOiEt
NH;
NH;
formula CiISImN& C&~N~O ClBHZlN20
mp, "C
108
78 116 105 89 64 90 132 94 117 127 94 88
95 138 136 109 69 oil 82 132 159 117 117 99.5 96 78 92 103 109 92 104 109 144 71
C;H&1N2O3 CnHnClN203 CaH&N203 CZOHBClNZ C21H&lN20 C18HlBClN20 CleH2lClNZO ClBH21C" CdpClNzO Co,HmClNoO C,H,C~N;O C22HnClNzO C%H&lN20 CNH,ClN2O Cl8HlBC1N202
Scheme IV Pip
H3c0w NaN02,H2S04,Cu
\
O
35-40%
F
51
20: R = H 18: R=C1
19:
I
NaN02,HBr
0
R=OCH3
-1 : R = H 5: R = C1 -6: R = OCH3
Pip
c1
CuC12,DMS0
Y 0
Pip
0
Pip
_. 17
NHMe ClCOzCHzPh
NaH,CH3I
HC1,EtOH C1
22-23-
Seven out of the 30 compounds evaluated in this test were chosen on the basis of their activity on at least one
87%
73%
24
0
pip
25
o
Pip
of the mitogen-induced responses: compounds 5,21,27, 28,29,32, and 34. No distinction could be made, however,
Table 11. Proliferative Response to Mitogens concanavaline A PHA _ _ _ _ ~ _ _PWM dose: dose: dose: stimulated stimulated .uelmL control stimulated stimulated pg/mL control stimulated stimulated pg:mL control index' (pM) blastogenesis" blastogenesisb index" (pM) blastogenesis" blatogenesis* no. ( p M ) blastogenesis" blastogenesis* indexc 55.7 f 1.1 1.14 1 5 (17) 188.1 f 1.6 167.0 f 34.5 0.89 40 (136) 48.9 f 5.2 53.8 f 4.3 48.9 f 1.4 2 5 (16) 179.7 f 17.2 283.2 f 19.4 1.58 40 (130) 0.91 72.2 f 7.8 3 5 (17) 69.9 f 8.8 268.2 f 49.9 165.6 f 18.8 0.61 80 (273) 0.96 40.5 f 5.6 7.0 f 1.6 11.1 f 0.6 1.59 1.39 5 (17) 4 5 (17) 118.7 f 10.7 123.4 f 16.6 56.4 f 13.2 1.04 40 (132) 12.8 f 1.8 43.5 f 9.2 3.4 36.5 f 13.6 101.9 f 3.3 5 5 (13) 194.5 f 28.6 269.5 f 45.7 1.39 40 (107) 2.81 10 (27) 36.3 f 1.9 54.3 f 3.7 1.5 6 5 (15) 322.1 f 11.3 103.3 f 1.4 121.8 f 2.4 1.13 1.18 5 (15) 363.6 f 11.3 10 (30) 7 5 (15) 279.6 f 15.7 68.8 f 10.7 61.5 f 5.9 0.89 250.0 f 19.6 0.89 80 (247) 158.4 f 31.1 8 5 (14) 80 (226) 137.4 f 23.0 44.9 f 3.5 48.8 f 2.5 1.09 1.15 9 5 (14) 136.6 f 19.1 151.5 f 19.0 48.4 f 5.3 64.4 f 8.7 1.11 1.33 80 (220) 46.7 f 8.2 46.4 f 10.2 0.99 10 5 (14) 280.0 f 20.3 246.2 f 68.4 105.5 f 2.2 115.9 f 29.1 1.10 5 (14) 10 (27) 0.88 77.1 f 4.8 11 5 (15) 152.6 f 10.6 84.5 f 4.1 1.35 0.91 206.0 f 0.8 20 (60) 85.8 f 17.8 12 5 (15) 80.0 f 4.0 1.07 165.5 f 8.7 150.0 f 14.3 20 (61) 1.1 40.2 f 3.9 40.9 f 0.4 1.14 13 5 (15) 316.0 f 56.2 102.8 f 7.2 105.0 f 12.4 1.02 5 (15) 343.8 f 27.8 10 (30) 1.09 14 5 (16) 389.9 f 35.9 47.9 f 0.7 62.4 f 4.7 1.3 1.37 5 (16) 414.1 f 5.1 98.8 f 3.7 135.9 f 2.9 10 (32) 1.06 79.0 f 7.3 34.3 f 4.6 36.0 f 2.6 1.05 1.01 5 (14) 15 5 (14) 332.0 f 25.6 297.7 f 48.6 79.9 f 4.9 10 (28) 0.89 16 5 (14) 160.9 f 8.8 93.7 f 3.6 42.7 f 6.3 59.9 f 10.6 0.58 0.71 40 (112) 17 5 (14) 14.6 f 0.7 8.2 f 1.0 0.56 55.6 f 3.6 7.5 (21) 68.7 f 4.4 1.23 15.5 f 1.0 0.89 17.4 f 2.8 18 5 (15) 7.5 (23) 92.7 f 6.7 62.7 f 5.8 0.68 19 5 (16) 127.5 f 24.5 20.8 f 1.8 15.5 f 2.4 0.74 10 (32) 165.1 f 25.7 1.29 20 5 (18) 24.7 f 0.7 15.1 f 0.9 1.63 13.6 f 1.3 9.0 f 4.5 0.66 10 (36) 21 5 (12) 2.03 16.3 f 1.9 8.0 f 2.5 20.3 f 0.6 19.5 f 1.1 0.96 21.3 f 0.5 1.17 24 5 (15) 10 (31) 18.2 f 0.6 21.4 f 0.6 14.9 f 1.5 18.6 f 1.2 0.87 10 (28) 25 5 (14) 0.85 17.6 f 0.5 21.3 f 6.1 47.7 f 4.4 44.8 f 5.5 0.94 24.6 f 3.1 26 5 (16) 0.86 10 (32) 27 5 (15) 124.4 f 6.7 41.3 f 8.2 45.0 f 10.5 1.07 141.6 f 20.1 1.14 80 (243) 131.5 f 13.3 58.1 f 3.7 1.04 55.8 f 2.4 28 5 (16) 2.24 294.8 f 329 40 (130) 29 5 (15) 48.6 f 3.9 75.8 f 2.6 67.3 f 8.8 1.13 1.03 50.2 f 3.9 40 (117) 59.1 f 8.8 55.0 f 0.91 0.93 114.8 f 11.7 137.5 f 21.8 1.20 5 (13) 30.5 f 11.6 30 5 (13) 31.9 f 10.8 1.04 10 (30) 30.4 f 2.6 37.4 f 7.8 1.23 88.7 f 27.7 1.29 5 (15) 114.6 f 6.7 31 5 (15) 319.5 f 22.0 348.0 f 61.7 1.09 10 (29) 51.3 f 10.0 59.1 f 6.6 1.15 1.04 10 (27) 78.4 f 13.9 211.8 f 40.1 289.2 f 33.0 81.7 f 9.1 1.36 32 5 (14) 10 (27) 27.4 f 6.5 35.1 f 2.4 1.88 328.0 f 41.0 308.4 f 65.1 108.2 f 12.8 79.5 f 4.1 0.73 5 (12) 33 5 (12) 0.94 10 (25) 59.9 f 5.3 54.4 f 9.8 0.92 263.2 f 23.4 95.7 f 4.8 115.3 f 15.1 1.20 10 (26) 34 5 (13) 294.1 f 37.1 1.12 10 (26) 45.0 f 3.3 52.6 f 3.8 1.17 107.9 f 7.1 88.7 f 14.3 35 5 (15) 374.8 f 53.5 281.1 f 38.3 0.75 10 130) 0.82 5 (15) Control blastogenesis: proliferation induced by themitogen alone (Con A, PWM, PHA). *Stimulated blastogenesis: maximal proliferation induced by the test compound in the presence of the mitogen. 'Results are expressed as the mean f standard deviation after three different cultures.
