Thiophene substituted dihydropyridines

The crystal structures of 4-(2-thiophenyl)-2,6-dimethyl-1,4-dihydropyridine -3,5-bis(methoxycarbonyl) (I)[a = 10.273(5) Angstrom, b = 10.428(5) Angstro m, c = 14.799(9) Angstrom, beta = 98.13(4)degrees, P2(1)/c], 4-(3-thiopheny l)-2,6-dimethyl-1,4-dihydropyridine-3,5-bis(methoxycarbonyl) (II) [a = 10.6 36 (9) Angstrom, b = 10.372(8) Angstrom, c = 15.043(15) Angstrom, beta = 98 .13(6)degrees, P2(1)/c], and 4-(2-thiophenyl)-2,6-dimethyl-1,4-dihydropyrid ine-3,5-bis(ethoxycarbonyl) (III) [a = 26.793(16) Angstrom, b = 7.610(6) An gstrom, c = 17.612(10) Angstrom, beta = 97.61(2)degrees, C2/c] reveal patte rns of hydrogen bonding pertinent to behavior of these members of the 1,4-d ihydropyridine family in receptor site docking. Carbonyl groups substituted at C3 and C5 are seen in ap conformation when hydrogen bonded. Sulphur ato ms of the hetero rings do not participate in hydrogen bonding. In these str uctures the position of the herero atom is seen to be disordered over two e quivalent sites. Thus, there is no demonstrated preference for conformation of the hetero ring.