Phosphorus oxychloride → 4-Chlorothieno[2,3-d]pyrimidine

Participants

Reaction Conditions

Reaction Steps

Thieno[2,3-d]pyrimidin-4(3H)-one (1.2 g, 7.9 mmol) was diluted in 1,2-dichloroethane (10 mL). Phosphorous oxychloride (1.4 mL, 15.7 mmol) was added. The reaction was stirred at 90° C. for 16 hours. An additional equivalent of phosphorous oxychloride (0.7 mL, 7.9 mmol) was added and the solution continued stirring for 4 hours. The solution was cooled, concentrated, and neutralized with saturated NaHCO3 solution. The material was extracted with a chloroform:isopropyl alcohol mixture and the organic layer was separated and concentrated. Flash chromatography gave the title compound (0.39 g, 29%).

Provenance & Evidence