A new coupling agent, 1-methanesulfonyloxy-6-trifluoromethyl-benzotriazole (3), was prepared by the reaction of 1-hydroxy-6-trifluoromethylbenzotriazole (1) and methanesulfonyl chloride. 3 was reacted with 2-(2-amino-4-thiazolyl)-2-synalkoxyi minoacetic acid (4) to give a mixture of active intermediates (5 and 6), which was treated with 7-aminocephalosporanic acid derivatives (10) to afford cephalosporin derivatives (11) in short reaction time with high yields.