The reaction of 7-aminocephalosporanic acid (I) with alpha-sulfophenylacetyl chloride (II) by means of NaOH and NaHCO3 in ether gives 7-(alpha-sulfophenylacetamido)cephalosporanic acid (III), which is then condensed with isonicotinamide (IV) by means of KSCN and pyridine in water.