| abstract |
New intermediates (III) - (VI) and (VIII) for the preparation of cephalosporins, comprising a substituted benzyloxyimino group in position 7, are new. New intermediates of formulas (III) - (VI) and (VIII) for the preparation of cephalosporins, comprising a substituted benzyloxyimino group in position 7, are new. R1p-R5p = R1-R5 or protected group; R1-R3, R5 = H, halo, OH, 1-4C alkyl (optionally substituted with at least one halo), 1-4C alkoxy, mercapto, 1-4C alkylthio, nitro, cyano, amino (optionally substituted with one 1-4C alkyl), 2-8C dialkylamino, carbamoyl, 2-5C alkylamino-carbonyl, 3-9C dialkylamino-carbonyl, 2-5C alkoxycarbonyl, 1-8C acyloxy or SO2-N(Rx)(Ry); Rx, Ry = H or 1-4C alkyl; R4 = OH or 1-8C acyloxy; R7 = ester residue; R8 = H or protecting group; and provided R3 and R5 are the same as R4 when: (1) R1, R2 or R3, or R2, R4 or R5 is F, Br, I or cyano; or (2) R1 and R5 are both other than H; or (3) R2 and R5 are both Cl. |