In 120 ml of acetonitrile were suspended 9.8 g of 5-hydr- oxymethyl-7-mercapto-2-methyl-s-triazolo[1,5-a]pyrimidine and 13.6 g of 7-aminocephalosporanic acid, and 22 ml of boron trifluoride-ethyl ether complex was added to the suspension and the mixture was stirred at 50° C. for 3 hours. After cooling the reaction mixture, 250 ml of water was added thereto and the mixture was adjusted to pH 2 with conc. aqueous ammonia. Precipitated crystal was collected by filtration, washed with water, washed with acetone and then dried to obtain 11.6 g of the title compound.
