STRUCTURE OF DIPHENYLMETHYL 7-BETA-AMINO-7-ALPHA-METHOXY-3-[(1-METHYL-1H-TETRAZOL-5-YLTHIO)METHYL]-3-CEPHEM-4-CARBOXYLATE

Diphenylmethyl 7-beta-amino-7-alpha-methoxy-3-[(1-methyl-1H-tetrazol-5-ylthio)methyl]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate, C24H24-N6O4S2, M(r) = 524.61, orthorhombic, P2(1)2(1)2(1), a = 9.829 (1), b = 13.290 (2), c = 18.864 (3) angstrom, V = 2464.2 (6) angstrom3, Z = 4, D(x) = 1.414 g cm-3 , lambda(Cu K-alpha) =1.5418 angstrom, mu = 22.8 cm-1, F(000)=1096, T = 295 K, R = 0.048 for 1654 reflections with I greater-than-or-equal-to 2-sigma(I). The S(1)-C(2) bond is similar to the S(1)-C(6) bond in cephamycin while the former bond is always longer by ca 0.62 angstrom in cephalosporin. The orientation of the carboxyl group with respect to the 3-cephem nucleus is not affected by the presence of the bulky diphenylmethyl group. The 7-alpha-methoxy group assumes the same conformation in cephamycin and oxacephalosporin. The (1-methyl-1H-tetrazol-5-ylthio)methyl moiety is perpendicular to the dihydrothiazine ring. Crystal packing consists only of van der Waals interactions.