反应详情

A solution of formic acid (1.6 g.) and acetic anhydride (3.6 g.) was stirred at 50° C. for an hour. After cooling, 2-(2-aminothiazol-4-yl)-2-(2-hydroxyethoxyimino)acetic acid (syn isomer, 1 g.) was added to the solution and stirred at room temperature for 3 hours. Diisopropyl ether was added to the resultant solution, and the precipitates were filtered out. The filtrate was concentrated in vacuo, and the residue was pulverized with diisopropyl ether. The precipitates were collected by filtration to give 2-(2-formamidothiazol-4-yl)-2-(2-formyloxyethoxyimino)acetic acid (syn isomer, 0.7 g.).

1. temperatureAfter cooling
2. filtrationthe precipitates were filtered out
3. concentrationThe filtrate was concentrated in vacuo
4. filtrationThe precipitates were collected by filtration