A solution of 0.18 g. of pivaloyloxymethyl 3-methyl-7-aminoceph-3-em-4-carboxylate (0.18 g.) and 2-fluoroimidazole hydrochloride (0.14 g.) in DMF (1 ml.) and acetonitrile (1 ml.) was heated at 50° for 7 hours. After evaporation the residue was chromatographed on silica gel using CH2Cl2 /MeOH 95:5 v/v as eluant. The oily product was treated with one equivalent of HCl in MeOH. The solution was evaporated and the residue was triturated with ether and filtered to give pivaloyloxymethyl 7-(imidazol-2-yl)amino-3-methylceph-3-em-4-carboxylate hydrochloride having the following n.m.r. in d6DMSO+CD3COOD: 1.2 (s, 9H); 2.1 (s, 3H); 3.6 (m, 2H); 5.25 (d, 1H); 5.7 (d, 1H); 5.85 (m, 2H); 7.05 (s, 2H).
