CEPHALOSPORIN-SYNTHESE

1424375 dl - Cephalosporin derivatives MERCK & CO Inc 10 April 1973 [14 April 1972 30 June 1972 10 Oct 1972 5 March 1973] 5964/75 Divided out of 1424373 Heading C2C Novel dl compounds of the Formula (I) in which R is H or an acyl group, B is H, CH 3 or OCH 3 , R 1 is H or a blocking group, and R1 is H or halogen, C 1-6 alkoxy, aryloxy, aralkoxy, (C 1-6 alkoxy)-(C 1-6 alkoxy), heterocyclic-substituted mercapto or acyloxy, may be obtained (1) by reducing a compound of the formula and optionally acylating the product, or by carrying out the reduction in the presence of an acylating agent, or (2) by acylating a dl compound of Formula I above in which R is H. The 7-amino compounds may be reacted with benzaldehyde or p-nitrobenzaldehyde to form a 7-benzylideneamino derivative which can then be reacted with an appropriate reagent to introduce a methyl or methoxy group at position 7, then the amino residue is regenerated by reacting the imine compound with an amine, e.g. aniline, hydrazine or its derivatives, in the presence of an acid catalyst.