反应详情

To a solution of 4-thiophen-2-yl-pyridine (3.33 g, 20.7 mmol) in THF (137 mL) at −78° C. is added n-BuLi (8.7 mL of a 2.5 M solution in hexanes, 21.7 mmol). After stirring for 15 minutes, SO2 gas is bubbled through the solution for 30 minutes. The solution is then allowed to warm to room temperature and stirred overnight. The solution is concentrated to dryness and the resulting solid is suspended in hexane (100 ml). To the ice-cooled solution is added sulfuryl chloride (1.7 mL. 21.7 mmol). The ice bath is removed and the suspension is stirred for 2 hours. The mixture is then concentrated to dryness and diluted with ethyl acetate and washed with saturated NaHCO3 (aq), water and brine. The organic layer is dried over MgSO4, filtered and concentrated to give a yellow solid as the title product (3.39 g, 13.1 mmol) which is used in the subsequent step without further purification.

1. customSO2 gas is bubbled through the solution for 30 minutes
2. stirringstirred overnight
3. concentrationThe solution is concentrated to dryness
4. temperatureTo the ice-cooled solution
5. customThe ice bath is removed
6. stirringthe suspension is stirred for 2 hours
7. concentrationThe mixture is then concentrated to dryness
8. additiondiluted with ethyl acetate
9. washwashed with saturated NaHCO3 (aq), water and brine
10. dry with materialThe organic layer is dried over MgSO4
11. filtrationfiltered
12. concentrationconcentrated