| 摘要 |
A process for preparing cephalosporins of structure: III <IMAGE> where R is hydrogen, C1 to C4 alkyl, cyano-methyl-, thienyl-methyl, furyl-methyl-, naphthyl-methyl-, phenyl-methyl-, phenoxy-methyl-, phenyl-isopropyl-, phenoxy-isopropyl-, pyridyl-4-thiomethyl-, and tetrazolyl-1-methyl; R1 is hydroxyl, C2 to C4 alkoxy, trichloroethoxy-, benzyloxy-, p-methoxy-benzyloxy-, p-nitrobenzyloxy-, benzhydryloxy-triphenylmethoxy-, phenacyloxy-, and p-halophenacyloxy; Z is hydrogen, hydroxyl, -O-alkyl, -O-CO-alkyl, -Br, -I, -N3, -NH2, -O-CO-CH3, -O-CO-NH2 and an -S-mononuclear nitrogen heterocyclic ring; WHEREIN A COMPOUND OF STRUCTURE (I') <IMAGE> is reacted in a suitable solvent at a temperature between -20 DEG C and +80 DEG C, in the presence of an aqueous organic or inorganic acid with an azoderivative of the formula: <IMAGE> where R2 and R3 are equal or different and represent lower alkyl, a mononuclear aryl ring, CN-, a mononuclear heterocyclic ring, or the radicals -COR4, -COOR4, <IMAGE> -CONHR4, or R2 and R3 together may represent the residues: <IMAGE> <IMAGE> where T represents >CH2, >N - R4, and R4 is lower alkyl, a mononuclear aryl ring or a mononuclear heterocyclic ring, to give a compound of structure: (II') <IMAGE> in which R, R1, R2, R3, and Z have the meanings given above, and said intermediate (II 40 ) is reacted in a suitable solvent at a temperature between -100 DEG C and +120 DEG C with a compound selected from the class consisting of inorganic bases, to finally give the desired compound (III) which is isolated and purified in known manner.
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