反应详情

A solution of ethyl chlorocarbonate (4.90 mL, 51.7 mmol) in tetrahydrofuran (THF, 60 mL) was slowly added to a mixture of tert-butyl 3-amino-1H-thieno[2,3-c]pyrazole-5-carboxylate (12.0 g, 50.2 mmol) and diisopropylethylamine (DIEA, 51.5 mL, 301 mmol) in THF (300 mL), maintaining the temperature between −5 and −10° C. The reaction was kept at the same temperature for 5 minutes then allowed to reach room temperature. The obtained mixture was evaporated to dryness under vacuum and the residue extracted with ethyl acetate (AcOEt) and water. The organic layer was separated, dried over sodium sulfate and evaporated to dryness. The resulting raw material was triturated with diethyl ether to give 13.7 g of the title compound as a white solid.

1. temperaturemaintaining the temperature between −5 and −10° C
2. customto reach room temperature
3. customThe obtained mixture was evaporated to dryness under vacuum
4. extractionthe residue extracted with ethyl acetate (AcOEt) and water
5. customThe organic layer was separated
6. dry with materialdried over sodium sulfate
7. customevaporated to dryness
8. customThe resulting raw material was triturated with diethyl ether