Ethyl Acetate → 7beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[N,N-dimethyl-N-((5-hydroxy-4-oxo-1,4-dihydropyridin-2-yl)methyl}ammonio]methyl-3-cephem-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

7β-Amino-3-[N,N-dimethyl-N-{(5-hydroxy-4-oxo-1,4-dihydropyridin-2-yl)methyl}ammonio]methyl-3-cephem-4-carboxylate dihydrochloride (181 mg) was suspended in tetrahydrofuran (9.1 ml). To the suspension was added N-(trimethylsilyl)acetamide (788 mg), and the mixture was stirred at 35° C. for 30 minutes and cooled to 5° C. To the resulting solution was added a solution of 2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-carboxy-1-methylethoxyimino)acetic methanesulfonic anhydride (syn isomer) (169 mg) in tetrahydrofuran (0.5 ml). The mixture was warmed to 20° C. and stirred for 1.2 hours. The mixture was poured into ethyl acetate (200 ml) and the resulting precipitates were collected by filtration, washed with ethyl acetate and diisopropyl ether and dried in vacuo. The powder was suspended in water (40 ml) and adjusted to pH 1 with 1N hydrochloric acid. After the insoluble materials were removed by filtration, the filtrate was chromatographed on Diaion HP-20 (15 ml) and the elution was carried out with 15% aqueous isopropyl alcohol. The eluate was lyophilized to give 7β-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-[N,N-dimethyl-N-{(5-hydroxy-4-oxo-1,4-dihydropyridin-2-yl)methyl}ammonio]methyl-3-cephem-4-carboxylate (syn isomer) (120 mg).

Provenance & Evidence