Abstract: The alkali metal salts of the reaction products of ampicillin or amoxicillin with 5-formyl-2-furansulfonic acid are found to be stable, useful water-soluble forms of the penicillin antibiotics especially advantageous for parenteral administration.

Abstract: Improved yields of 7-[D-.alpha.-amino-.alpha.-(4-hydroxy- and 3-chloro-4-hydroxy-phenyl)acetamido]-3-methyl-3-cephem-4-carboxylic acids are obtained by acylating 7-aminodesacetoxycephalosporanic acid with the mixed anhydride (from ethyl chloroformate) of the ring-substituted 2-phenylglycine when the latter's .alpha.-amino group has been blocked by reaction with a .beta.-keto compound such as methyl acetoacetate. Improved purification processes include the use of dimethylformamide and acetonitrile solvates and solvates and bis-anthraquinone-1,5-disulfonic acid salts.