[Synthesis]
5-Methyl-2,4-dinitroaniline (CAS: 5267-27-6) (5 g, 25.36 mmol) was used as a raw material, which was dissolved in ethanol (150 mL) and the resulting solution was heated at 100 °C. Sodium sulfide (9 g, 115 mmol) dissolved in water (150 mL) was added to the reaction mixture. The resulting mixture was cooled to room temperature and stirring was continued for 2 hours. Upon completion of the reaction, the mixture was poured into water and extracted with ethyl acetate. The organic layers were combined, washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by fast column chromatography on silica gel to afford 4-methyl-5-nitrobenzene-1,2-diamine (2.9 g, 68% yield) as a yellow solid. The product was characterized as follows: 1H NMR (400 MHz, CDCl3): δ 7.5 (s, 1H), 6.4 (s, 1H), 4.35 (br s, 2H), 3.6 (br s, 2H), 2.45 (s, 3H). LC-MS: tR = 0.92 min, m/z = 168 [M + 1]. |