PROCESS FOR PREPARING 6-(D(-)-ALPHA-(4-C1 C4 ALKYL-2,3-DIOXO-1-PIPERAZINO-CARBONYLAMINO)-PHENYLACETAMIDO)PENICILLANIC ACID

摘要

6-Substituted penicillanic acid, especially 6-[D(-)-alpha(4-alkyl- 2,3-dioxo-1-piperazino carbonylamino)-phenylacetamido penicillanic acid(I), used as an antibiotic agent is prepared from an ampicillin suspension or solution added into a mixture of ethyl acetate and water in the presence of a base by means of the addition of a halogenated compd. of 4-C1-C4 alkyl-2,3-dioxo-1piperazinocarbonyl; where R = C1-C4 alkyl. Product is obained from the precipitated crystals by washing with water and isopropanol and drying.