Diethyl Ether → 7beta-[2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-(1-tert-butoxycarbonyl-1-methylethoxyimino)acetamido]-3-(3-amino-2-methyl-1-pyrazolio)methyl-3-cephem-4-carboxylate trihydrochloride

Participants

Reaction Steps

To a solution of 7β-amino-3-(3-amino-2-methyl-1-pyrazolio)methyl-3-cephem-4-carboxylate trihydrochloride (2 g) and N-(trimethylsilyl)acetamide (6.28 g) in tetrahydrofuran (40 ml) was added (Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-tert-butoxycarbonyl-1-methylethoxyimino)acetyl chloride hydrochloride (1.84 g) under ice-cooling. After being stirred for 1 hour, the reaction mixture was added dropwise to ethyl ether (300 ml), and the resulting precipitate was collected by filtration to give 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-tert-butoxycarbonyl-1-methylethoxyimino)acetamido]-3-(3-amino-2-methyl-1-pyrazolio)methyl-3-cephem-4-carboxylate trihydrochloride (syn isomer) (3.4 g).

Provenance & Evidence