反应详情

a solution of 26 gm of thiopropionamide in 100 cc of ethanol is mixed with a solution of 36.5 gm of ethyl 2-chloro-3-oxo-propionate in 50 cc of ethanol. The reaction mixture is left in contact overnight, then the alcohol is evaporated off. The residue is dissolved in ether, the ethereal phase is washed with an aqueous 20% sodium carbonate solution, then with water. The oil obtained is distilled and the fraction coming off at 80° C. to 90° C. under a pressure of 0.5 mm is recovered. This fraction is saponified with an alcoholic solution of potassium hydroxide, then acidified and recrystallized from toluene. 2-Ethyl-5-thiazolecarboxylic acid is obtained in the form of colorless crystals, soluble in ethanol and sodium hydroxide, insoluble in water, melting at 157° C.

1. customthe alcohol is evaporated off
2. dissolutionThe residue is dissolved in ether
3. washthe ethereal phase is washed with an aqueous 20% sodium carbonate solution
4. customThe oil obtained
5. distillationis distilled
6. customcoming off at 80° C. to 90° C. under a pressure of 0.5 mm
7. customis recovered
8. customrecrystallized from toluene