| abstract |
PURPOSE:To profitably produce the compound of a carbapenem antibiotic useful used as an antibacterial agent by reacting a specific carbapenem compound with a pyrazolo-triazolium compound and subsequently removing the protecting group from the reaction product to form an intramolecular salt. CONSTITUTION:A carbapenem compound of formula I (R<1> is carboxy-protecting group; R<3> is acyl) is reacted with 6,7-dihydro-6-mercapto-5H-pyrazolo[1,2-a][1,2,4] triazolium to produce a compound of formula III. If necessary, the protecting group is removed from the compound of formula III to provide the objective carbapenem compound of formula IV consisting of (1R,5S,6S)-2-[6,7-dihydro-5H- pyrazolo [1,2-a][1,2,4] triazolium-6-yl)] thio-6-[(R)-1-hydroxyethyl] 1-methyl- carbapenem-3-carboxylate (salt). |