Synthesis of S-benzylcysteinylglycine Ethyl Ester under Microwave Irradiation

S-benzylcysteinylglycine ethyl ester(2) was synthesized by de-protect reaction of S-benzyl-N-benzyloxycarbonyl-cysteinylglycine ethyl ester(1) with HBr-AcOH under microwave irradiation. The structure was confirmed by 1H NMR and IR. The optimum reaction conditions at 30 ℃ for 20 min were as follows:1 was 2.9 mmol; n(1) ∶n(HBr-AcOH) was 1 ∶6; power was 200 W. The yield of 2 was 87% under the conditions.