827-32-7

102169-44-8

General procedure for the synthesis of 4-bromo-5-methylbenzene-1,2-diamine from 4-bromo-5-methyl-2-nitroaniline: 4.00 g (17.312 mmol) of 4-bromo-5-methyl-2-nitroaniline was dissolved in 100 mL of ethanol, and 15.63 g (69.248 mmol) of stannic chloride (II) dihydrate was added. The reaction mixture was stirred at 70 °C overnight. After completion of the reaction, it was cooled to room temperature, diluted by adding an appropriate amount of water, and the pH was adjusted to a weak base with saturated aqueous sodium bicarbonate solution. Subsequently, it was extracted three times with ethyl acetate, the organic phases were combined and dried with anhydrous sodium sulfate. The dried organic phase was concentrated by rotary evaporation under reduced pressure to obtain the crude product. The crude product was dried under high vacuum to finally obtain 3.23 g (89% yield) of the target compound 4-bromo-5-methylbenzene-1,2-diamine. The product was analyzed by LC-MS (Method 1): retention time Rt = 1.07 min; mass spectrum (EIpos): m/z = 201 [M + H]+. 1H-NMR (400 MHz, DMSO-d6) data were as follows: δ [ppm] = 2.08 (s, 3H), 4.51 (s, 2H), 4.52 (s, 2H), 6.43 (s. 1H), 6.66 (s, 1H).