Cephalosporin derivatives

Claim 1

A compound of the formula ##STR43## wherein R 1 is hydrogen or a conventional amino-protecting group, R 2 is a straight or branched chain alkyl group containing from 1 to 4 carbon atoms, allyl, propargyl, 2-butenyl, 2-butynyl, 3-butenyl, 3-butynyl, cyclo(lower)alkyl or a group of the formula ##STR44## in which R 3 and R 4 each are independently hydrogen, methyl or ethyl, or R 3 and R 4 , taken together with the carbon atom to which they are attached, may be a cycloalkylidene ring containing from 3 to 5 carbon atoms, and R 5 is hydrogen, carboxy, formyl, amino, carbamoyl, (lower)alkylamino, di(lower)alkylamino, guanidino, amidino, (lower)alkyl, (lower)alkoxy, (lower)alkylthio or a group of the formula ##STR45## in which R 6 and R 7 each are independently hydrogen or (lower)alkyl, or when taken together with the nitrogen atom to which they are attached, R 6 and R 7 represent a 5 to 7-membered saturated ring optionally containing an additional hetero atom selected from N, O and S, or R 5 is a group of the formula ##STR46## in which R 8 is hydrogen, (lower)alkyl, amino(lower)alkyl, (lower)alkoxy, amino, (lower)alkylamino or ##STR47## in which R 9 and R 10 are each (lower)alkyl or, when taken together with the nitrogen atom to which they are attached, R 9 and R 10 represent a 5 to 7-membered saturated ring optionally containing an additional hetero atom selected from N, O and S; or a nontoxic pharmaceutically acceptable salt, physiologically hydrolyzable ester or solvate thereof.