Thieno[3,2-b]pyridine

Synthesis

General procedure for the synthesis of thieno[3,2-b]pyridine from 7-bromothieno[3,2-b]pyridine: 7-bromothieno[3,2-b]pyridine (3.69 g, 17 mmol) was dissolved in anhydrous THF (20 mL) and the solution was cooled to -78 °C. At -78 °C, n-BuLi (1.6 M hexane solution, 21.2 mL, 34 mmol) was slowly added and the reaction mixture was stirred at this temperature for 20 min. Subsequently, a mixed solution of MeOH/H2O (1:1, 20 mL) was added and the reaction mixture was warmed to room temperature and stirring was continued for 1 hour. Upon completion of the reaction, the reaction mixture was extracted with CH2Cl2. The organic phase was washed with saturated NaCl solution, dried over anhydrous Na2SO4 and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography with the eluent being 100% hexane to hexane:ethyl acetate (10:1) to afford thieno[3,2-b]pyridine (1.44 g, 62% yield). es/ms m/z 136 (M + 1)+.

References

[1] Patent: WO2008/36541, 2008, A1. Location in patent: Page/Page column 25
[2] Patent: WO2006/107784, 2006, A1. Location in patent: Page/Page column 89