7-bromo-benzo[c][1,2,5]thiadiazole-4-carbaldehyde

1239277-96-3

1071224-34-4

General procedure for the synthesis of 7-bromo-4-formylbenzo[C][1,2,5]thiadiazole from 4-bromo-7-(dibromomethyl)benzo[C][1,2,5]thiadiazole: aqueous silver nitrate (285 mg, 1.68 mmol, dissolved in 1.7 mL of water) was added to a stirred solution of compound A (260 mg, 0.67 mmol) in acetonitrile (8 mL) , followed by heating and refluxing for 2 hours. Upon completion of the reaction, it was cooled to room temperature and the reaction mixture was filtered to remove the resulting AgBr precipitate. The filtrate was extracted with dichloromethane, the organic phases were combined, washed with saturated brine, dried over anhydrous magnesium sulfate and filtered. The solvent was removed by rotary evaporation to afford compound B (7-bromo-2,1,3-benzothiadiazole-4-carbaldehyde) as a white solid (147 mg, 92% yield). The physical and spectral data of compound B were as follows: melting point 185-186 °C; IR (KBr) ν 3078, 3021, 2835, 2728, 1702, 1526, 1268, 1102, 937, 879 cm1; 1H NMR (CDCl3, 400 MHz) δ 10.71 (s, 1H), 8.09-8.03 (m, 2H); 13C NMR (CDCl3, 100 MHz) δ 188.0, 153.8, 152.1, 131.9, 131.5, 126.7, 121.7; HRMS (FAB+) m/z Calculated value C7H379BrN2OS [M]+ 241.9149, Measured value 241.9149; Calculated value C7H381BrN2OS [M]+ 243.9129, measured value 243.9137.