A mixture of 4-chloro-6-nitro[1]benzothieno[3,2-b]pyridine-3-carbonitrile (0.27 g, 0.9 mmol), 3-bromoaniline (3.16 g, 18.4 mmol), and pyridine hydrochloride (0.06 g) in 15 mL of DMSO is stirred in the microwave (PROLABO unit) at 140° C., power range 0-10%, for one hour. The final reaction mixture is cooled, dissolved in 100 mL of chloroform, washed with 2N HCl (2×50 mL), then with saturated aqueous sodium bicarbonate (50 mL), and dried over sodium sulfate. The solvent is evaporated, and the desired compound purified by silica gel chromatography, eluting with 9:1 chloroform/methanol. After washing with diethyl ether and ethyl acetate, 4-(3-bromoanilino)-6-nitro[1]benzothieno[3,2-b]pyridine-3-carbonitrile (0.215 g, 55%) is obtained as a yellow solid, m. p. 288-290° C.
