摘要 |
<p>An improvement, in per se known method for producing 7-aminocephem compound being important intermediate for producing antimicrobial substances, represented by the formula: <IMAGE> [II] wherein R1 is a hydrogen atom or a methoxy group and R2 is a residue of a thiol compound, or a salt or ester thereof, by reacting a compound of the formula: <IMAGE> [I] wherein R1 is as defined above and R is a carboxylic acid acyl group, or a salt or ester thereof, with a thiol compound or a salt thereof, is characterized in that the reaction is conducted in an organic solvent in the presence of a dihalophosphoric acid to give the compound [II] in high yield and high purity.</p> |