反应详情

A solution of ethyl 2-(2-aminothiazol-4-yl)-2-allyloxyiminoacetate (syn isomer, 3.6 g.), 2N aqueous solution of sodium hydroxide (14.1 ml.), tetrahydrofuran (14.1 ml.) and methanol (15 ml.) was stirred at 40° C. for 1.5 hours. The resultant solution was concentrated in vacuo, and the residue was dissolved in water. After the solution was adjusted to pH 2.8 with 10% hydrochloric acid under ice cooling, the precipitates were collected by filtration, washed with water and acetone in turn and dried to give 2-(2-aminothiazol-4-yl)-2-allyloxyiminoacetic acid (syn isomer, 1.91 g.), mp. 187° C. (dec.).

1. concentrationThe resultant solution was concentrated in vacuo
2. dissolutionthe residue was dissolved in water
3. filtrationthe precipitates were collected by filtration
4. washwashed with water and acetone in turn
5. customdried