Sodium Hydroxide → 7-Chlorothieno[3,2-b]pyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of thieno[3,2-b]pyridin-7-ol (3.8 g, 25 mmol) and phosphorus oxychloride (18 g, 120 mmol) was stirred at 105° C. for 2 hr. The reaction mixture was added to ice water, and basified with 8N aqueous sodium hydroxide solution. Ethyl acetate was added, the insoluble material was filtered off, and the filtrate was extracted with ethyl acetate. The collected organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate, and the insoluble material was filtered off. The filtrate was concentrated under reduced pressure, the obtained residue was purified by silica gel column chromatography (ethyl acetate/hexane=10/90→30/70), and the obtained solution was concentrated under reduced pressure to give the title compound (2.8 g, 66%) as a pale-yellow solid.

Provenance & Evidence