Bis(diphenylmethy1)7(R)-glutaroy lamino-3-hydroxyceph-3-em-4-carboxylate 1(S)-oxde is used as starting material to react with dichlorotriphenyl phosphine for synthesis of diphenylmethyl 7(R)-amino-3-chloroceph-3-em-4-carboxylate HCl salt by using“one pot” technology.Cefacor is synthesized by using phenylglycin chloride HCl salt as acylation reagent. The structure of cefacor is confirmed by IR,NMR and MS.