反应详情

温度

0 °C

Under nitrogen atmosphere, a solution of KOtBu (11.5 g) in THF (203 mL) was cooled to 0° C., and thereto were added dropwise ethyl chloroacetate (12.5 g) and ethyl formate (7.60 g) in THF (40 mL). After the addition, the mixture was stirred at 0° C. for 3 hours, and further stirred at room temperature for 16 hours. Water and a 6N aqueous hydrochloric acid solution were added to the mixture, and the mixture was extracted with Et2O, and dried over MgSO4. The solvent was evaporated under reduced pressure to give ethyl 2-chloroformyl-propionate. Under nitrogen atmosphere, to a solution of ethyl 2-chloroformylpropionate in acetone (250 mL) was added thioacetamide (7.74 g), and the mixture was stirred at 56° C. for 6 hours, and stirred at room temperature for 16 hours. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column (hexane/ethyl acetate=12.5/1→10/1) to give ethyl 2-methyl-1,3-thiazole-5-carboxylate (5.74 g, 32%).

1. additionAfter the addition
2. stirringfurther stirred at room temperature for 16 hours
3. extractionthe mixture was extracted with Et2O
4. dry with materialdried over MgSO4
5. customThe solvent was evaporated under reduced pressure