General procedure for the synthesis of 2-bromo-4-hydroxythieno[3,2-C]pyridine from the compound (CAS: 636999-00-3): intermediate 49 2-bromothieno[3,2-C]pyridin-4(5H)-one [(2E)-3-(5-bromothiophene-2-yl)]acryloyl azide (18.00 g, 69.7 mmol) was dissolved in dichloromethane (100 mL) and the resulting solution was slowly added dropwise to diphenyl ether (90 mL) at 150 °C. The reaction temperature was then raised to 220 °C and maintained for 1 hour. Upon completion of the reaction, the mixture was cooled to room temperature and ether was added to precipitate the solid. The solid product was separated by filtration to give 13.58 g (84.6% yield). The product was characterized by 1H NMR (270 MHz, DMSO-d6): δ 6.82 (d, J = 7.13 Hz, 1H), 7.27 (d, J = 6.86 Hz, 1H), 7.54 (s, 1H), 11.55 (s, 1H); the mass spectrum (MS) showed m/z 230.1 ([M-H]+); and the purity of the HPLC analysis was 92%.
![2-Bromothieno[3,2-c]pyridin-4(5H)-one Structure](/CAS/GIF/28948-60-9.gif)
