(6R)-trans-3-chloromethyl-7-[(2,5-dichlorophenyl)thioacetamido]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate diphenylmethyl ester   、                                                                                      
苯甲醚   、                                                                                      
三氟乙酸                                                                                                                                                              在
                                                                                                                                                                                 
乙醚                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                    反应 1.0h,
                                                                                                                以to give 5.20 g of (6R)-trans-3-chloromethyl-7-[(2,5-dichlorophenyl)-thioacetamido]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid as a white solid (70% yield), m.p. 125° C的产率得到(6R)-trans-3-chloromethyl-7-[(2,5-dichlorophenyl)thioacetamido]-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid