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

Participants

Reaction Conditions

Reaction Steps

A suspension of thieno[3,2-b]pyridin-7-ol (4.6 g, 30.4 mmol) in POCl3 (15 mL, 30.4 mmol) was refluxed at 105° C. for 4 hr. The solvent was evaporated to afford a dark brown oil that was cooled in an ice bath and diluted with cold water. The aqueous layer was adjusted to a basic pH (˜8) by adding an NH4OH solution. The aqueous mixture was extracted with EtOAc and DCM. The combined organic layers were washed with brine, dried over Na2SO4, filtered, and concentrated to afford an oil. Purification of the crude material by silica gel chromatography using a BIOTAGE® machine (hexanes:ethyl acetate 75:25) afforded the title compound as a pale buff solid (4.7 g, 91%). ESI MS (M+H)+=170.0.

Provenance & Evidence