反应详情

A mixture of methyl 3-(3-cyanopyridin-2-ylthio)propanoate (1.5 g, 6.8 mmol), sodium hydride (0.36 g, 15 mmol) and tetrahydrofuran (30 ml) was heated at reflux for 5 h. The reaction was quenched by the addition of ethanol (5 ml). The solvents removed under reduced pressure and the residue was treated with water (50 ml). The ph was adjusted to 6 and the mixture was filtered to yield 2-thioxo-1,2-dihydropyridine-3-carbonitrile (0.64 g). An analytically pure sample was prepared by recrystallisation from ethanol, yellow needles, mp 243-246° C. (lit. mp 248-250° C.). 1H NMR (DMSO-d6): 14.30 (br s, exchangeable, 1H), 8.12 (dd, 1H), 7.94 (dd, 1H), 6.86 ppm (dd, 1H). MW=136 confirmed by LC-MS, tr=5.27 min (Method C) MH+=137.

1. temperaturewas heated
2. temperatureat reflux for 5 h
3. customThe reaction was quenched by the addition of ethanol (5 ml)
4. customThe solvents removed under reduced pressure
5. additionthe residue was treated with water (50 ml)
6. filtrationthe mixture was filtered