| abstract |
New salts of 7-aminocephalosporanic acids of general formulan wherein R 1 is among others H, CH 3 or CH 3 O; R 2 is among others CH 3 , CH 3 0, Cl, azidomethyl, carbamoylmethyl, acetoxymethyl, thiomethyl, phenylthiomethyl, aliphatic, aromatic or heteroxyclic methylthiocarbonyl or methylthiohetero- cycle ; x is 3 to 5 ; and y is 2 to 4, in solution in an organic solvent, are used in the preparation of cephalosporins. |