METHOD OF PREPARING AMPICILLIN AND CEPHALEXIN Russian patent published in 1995 - IPC

FIELD: antibiotics of fused heterocyclic compounds. SUBSTANCE: products: ampicillin (AMP) and cephalexin (CP). Synthesis of AMP and CP were carried out from 7-aminodeacetoxycephalosporanic or aminopenicillanic acid and trimethylchlorosilane in the presence of triethylamine at 40 C followed by acidification with H₂SO₄ and addition of N-methyl-N-octylaniline (MOA) as a base and N-phenylglycine chloroanhydride. Then water is added to the reaction micture and aqueous phase is separated which is extracted with CH₂Cl₂, pH is brought about to 4.8-5.5 with alkali solution, and precipitate is separated. The yield of AMP is 92.3% at the content 99.1% and absence of MOA. The yield of CP is 82.7% at the content 99% The synthesis of the end products AMP and CP with high content of the basic substance is based on the use of indicated base instead of dimethylaniline. EFFECT: enhanced yield, simplified process, decreased toxicity. 2 cl