3-broMo-4H,5H-thieno[3,2-c]pyridin-4-one

799293-81-5

799293-83-7

The general procedure for the synthesis of 3-bromo-4-hydroxythienopyridine from the compound (CAS: 799293-81-5) is as follows: 100 mL of diphenyl ether was heated to 210 °C under nitrogen protection, followed by the slow addition of a solution of (E)-3-(4-bromothiophene-2-yl)acryloyl azide (9.95 g, 386 mmol) dissolved in 50 mL of diphenyl ether. The reaction mixture was maintained at 210 °C for 15 min. After completion of the reaction, it was cooled to room temperature and diluted with 100 mL of cyclohexane. The precipitate was collected by filtration and dried under vacuum to give 6.6 g (yield: 74.4%) of the target product 3-bromo-4-hydroxythienopyridine as a brown solid.