反应详情

温度

90 °C

A solution of 5-methylpyrazine-2-carboxylic acid (1.38 g, 10 mmol) in anhydrous N,N-dimethylformamide (5 mL) was treated with dimethylformamide dimethylacetal (5 mL). The resulting mixture was heated at 90° C. for 1 h and then at 125° C. for 2 h. The mixture was cooled to 25° C. and then was poured into water (100 mL). This solution was extracted with ethyl acetate (3×50 mL). The combined organic layers were washed with water (1×50 mL) and a saturated aqueous sodium chloride solution (1×50 mL), dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The resulting dark oil was triturated with diethyl ether/hexanes (5/1) to afford 5-(2-dimethylamino-vinyl)-pyrazine-2-carboxylic acid methyl ester (1.3 g, 63%) as an orange solid which was used without further purification.

1. temperatureThe mixture was cooled to 25° C.
2. extractionThis solution was extracted with ethyl acetate (3×50 mL)
3. washThe combined organic layers were washed with water (1×50 mL)
4. dry with materiala saturated aqueous sodium chloride solution (1×50 mL), dried over anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe resulting dark oil was triturated with diethyl ether/hexanes (5/1)