FORFARANDE FOR FRAMSTELLNING AV ESTRAR AV (6R, 7R-3-KARBAMOYLOXIMETYL-7-((Z)-2-(FUR-2-YL)-2-METOXIIMIONACETAMIDO)-CEF-3-EM-4-KARBONSYRA

摘要

Cephalosporin derivatives of the formula: in which R<1> denotes lower alkyl and R<2> denotes hydrogen or lower alkyl. In contrast to the free carboxylic acids, these novel esters are very well absorbed by the gastrointestinal tract and then hydrolyse rapidly to give corresponding carboxylic acids having a broad spectrum antibiotic action. They are prepared by esterification of the carboxyl group in the 4-position, by N-acylation of the 7-aminocephemcarboxylic acid ester or by carbamoylation of the hydroxymethyl group in the 3-position.