反应详情

To a solution of 2-chloro-3-cyanopyrazine (9.9 g, 73.8 mmol) and methyl 3-mercaptopropionate (9.36 mL, 84.5 mmol) in anhydrous dimethylformamide (40 mL) cooled to 4° C. was added solid sodium methoxide (4.7 g, 87.0 mmol). The reaction mixture was allowed to warm to room temperature overnight. The mixture was poured into water and extracted twice with ethyl acetate. The combined organic layers were washed once saturated aqueous sodium bicarbonate solution, five times with brine, then dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. Purification by column chromatography, on silica gel, eluting with a mixture of 7:3 hexanes:ethyl acetate gave methyl 3-(3-cyanopyrazin-2-ylthio)propanoate (7.2 g) as a pale yellow liquid. 1H NMR (300 MHz, CDCl3): 8.51 (d, 1H), 8.32 (d, 1H), 3.72 (s, 3H), 3.50 (t, 2H), 2.79 ppm (t, 2H). MW=223 confirmed by LC-MS, tr=11.11 min (Method Y) MH+=221-225.

1. extractionextracted twice with ethyl acetate
2. washThe combined organic layers were washed once saturated aqueous sodium bicarbonate solution, five times with brine
3. dry with materialdried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure
6. customPurification by column chromatography
7. washon silica gel, eluting with a mixture of 7:3 hexanes