反应详情

A solution of sodium hydroxide (1.6 g.) in water (30 ml.) was dropwise added over 5 minutes with stirring and ice-cooling to a suspension of ethyl 2-methoxyimino-2-(2-formamido-1,3-thiazol-4-yl)acetate (syn isomer) (5.14 g.) in water (60 ml.), and the resulting mixture was stirred for 1.5 hours at 10° to 20° C. The reaction mixture was adjusted to pH 7 with 10% hydrochloric acid and washed twice with ethyl acetate (100 ml.). To the aqueous layer was added ethyl acetate (200 ml.), and the resulting mixture was adjusted to pH 1 with 10% hydrochloric acid and extracted with the ethyl acetate. The aqueous layer was further extracted with ethyl acetate (100 ml.). Both ethyl acetate extracts were combined, washed with a sodium chloride aqueous solution (100 ml.) and dried over magnesium sulfate. The solvent was distilled off to give 2-methoxyimino-2-(2-formamido-1,3-thiazol-4-yl)acetic acid (syn isomer) (1.85 g.), mp 152° C. (dec.), which was recrystallized from ethyl acetate to give a pure compound, mp 167° C. (dec.).

1. stirringthe resulting mixture was stirred for 1.5 hours at 10° to 20° C
2. washwashed twice with ethyl acetate (100 ml.)
3. additionTo the aqueous layer was added ethyl acetate (200 ml.)
4. extractionextracted with the ethyl acetate
5. extractionThe aqueous layer was further extracted with ethyl acetate (100 ml.)
6. washwashed with a sodium chloride aqueous solution (100 ml.)
7. dry with materialdried over magnesium sulfate
8. distillationThe solvent was distilled off