反应详情

A solution of isopentyl nitrite (5.9 ml) in tetrahydrofuran (50 ml) was dropwise added to a mixture of 2-(2-aminothiazol-4-yl)-2-(benzhydryloxycarbonylmethoxyimino)acetic acid (syn isomer) (10.6 g) in tetrahydrofuran (100 ml) at 50 to 55° C. under stirring and the mixture was stirred at 55 to 60° C. for 30 minutes. Tetrahydrofuran was evaporated in vacuo. The residue was dissolved in a mixture of ethyl acetate and water and the mixture was adjusted to pH 7.5 with 20% aqueous solution of potassium carbonate. The separated aqueous layer was adjusted to pH 2.0 with 10% hydrochloric acid and extracted with ethyl acetate. The extract layer was washed with saturated aqueous solution of sodium chloride, dried over magnesium sulfate and evaporated to give 2-(benzhydryloxycarbonylmethoxyimino)-2-(4-thiazolyl)acetic acid (syn isomer) (4.9 g).

1. stirringthe mixture was stirred at 55 to 60° C. for 30 minutes
2. customTetrahydrofuran was evaporated in vacuo
3. dissolutionThe residue was dissolved in a mixture of ethyl acetate and water
4. extractionextracted with ethyl acetate
5. washThe extract layer was washed with saturated aqueous solution of sodium chloride
6. dry with materialdried over magnesium sulfate
7. customevaporated