反应详情

A solution of 5-(4-fluorophenyl)-thieno[3,2-b]pyridin-7-ol (1.6 g) in phosphorus oxychloride (50 mL) is refluxed for 3 hours. After the excess amount of phosphorus oxychloride is removed under vacuum, the residue is treated with ethyl acetate (20 mL) and NaOH (2N, 20 mL). The mixture is then extracted with ethyl acetate (3×20 mL). The combined organic layers are washed with brine and dried over MgSO4. Evaporation of the solvent affords 7-chloro-5-(4-fluorophenyl)thieno[3,2-b]pyridine (1.5 g, 88% yield) as a white solid, m.p. 119-121° C.

1. customAfter the excess amount of phosphorus oxychloride is removed under vacuum
2. additionthe residue is treated with ethyl acetate (20 mL) and NaOH (2N, 20 mL)
3. extractionThe mixture is then extracted with ethyl acetate (3×20 mL)
4. washThe combined organic layers are washed with brine
5. dry with materialdried over MgSO4
6. customEvaporation of the solvent