反应详情

To a solution of 2.80 g of α-t-butyloxycarbonylamino-α-[2-(trichloroethoxycarbonylamino)thiazol-4-yl]acetic acid ethyl ester in 60 ml of 90% formic acid is added 2.80 g of zinc dust under cooling and stirring. The mixture is stirred for 1 hour and zinc dust is filtered off. The filtrate is poured into water and the resultant solution is extracted with ethyl acetate. The organic layer is washed with saturated sodium bicarbonate aq. solution and then water, and dried over anhydrous magnesium sulfate. The distillation of the solvent gives 1.26 g (yield, 71.2%) of α-t-butyloxycarbonylamino-α-(2-aminothiazol-4-yl)acetic acid ethyl ester as crystals. Melting point: 143°-144° C.

1. temperatureunder cooling
2. stirringThe mixture is stirred for 1 hour
3. filtrationzinc dust is filtered off
4. additionThe filtrate is poured into water
5. extractionthe resultant solution is extracted with ethyl acetate
6. washThe organic layer is washed with saturated sodium bicarbonate aq. solution
7. dry with materialwater, and dried over anhydrous magnesium sulfate
8. distillationThe distillation of the solvent