Process Development of Micafungin, a Novel Lipopeptide Antifungal Agent

The manufacturing process of Micafungin (1) which is a novel candin antifungal agent discovered and developed by Astellas Pharma Inc. was studied.A new asymmetric isoxazole ring formation which is key reaction for synthesis of side chain active ester 2 was developed via β-keto enamine intermediate.And also a reaction condition of selective acylation with FUN intermediate 3 and purification of Micafungin drug substance was investigated from the viewpoints of high quality and productivity.