The reaction of 3-hydroxymethyl-7-[2-(2-furyl)-2-methoxyiminoacetamido]-3-cephem-4-carboxylic acid (I) with chlorosulfonyl isocyanate (II) and then with sodium 2-ethylhexanoate gives sodium cefuroxime (III), which is then treated with 1-bromoethyl acetate (IV) in DMA.