7ALPHA-METHOXYCEPHALOSPORIN COMPOUNDS

摘要

1488224 7-Methoxycephalosporins SANKYO CO Ltd 20 Nov 1975 [30 Nov 1974] 47840/75 Heading C2C The invention comprises a process for preparing a 7# - amino - 7α- methoxy - 3 - cephem - 4- carboxylate of general Formula (III) (in which: R1 represents an acetoxy group, a carbamoyloxy group or a 1-methyl-1H-tetrazol - 5 - ylthio group; and Y+ represents a cation), which comprises reacting a 7#-arylmethyleneamino - 7α- methoxy - 3 - cephem - 4- carboxylate of general Formula (II) (in which B1 and Y+ are as defined above; n is 1 or 2; and Ar represents a substituted or unsubstituted, monocyclic or fused polycyclic benzenoid ring system) with a hydrazine compound. The invention also comprises a process for preparing compounds (I) (in which R represents cyanomethylthio, 1- cyanoethylthio, azidomethylthio, propargylthio, 2 - hydroxyethylthio, 2,3 - dihydroxypropylthio, methylsulphonyl, ethylsulphonyl, cyanoethylsulphonyl, isoxazol - 3 - yloxy, isoxazol - 3 - ylthio, 1,3,4 - thiadiazol - 2- ylthio, imidazol - 2 - ylthio or sydnon - 3 - yl) which comprises reacting (III) with a carboxylic acid of general Formula (IV) (in which R6 represents the group R or the group R in which any hydroxy groups have been protected) or with a functional equivalent of said acid (IV) to produce a compound of general Formula (V) (in which R1 and R6 are as defined above) and, if necessary, removing any protecting groups in the group R6. Compounds (II) are made by treating corresponding 7 - arylmethyleneamino - 3 - cephem - 4- carboxylates (obtained by Schiff base formation) with oxidizing agent and methanol.