952511-74-9

Step 2: A mixture of 1-bromo-2-methyl-3,4-dinitrobenzene (40 g, 154 mmol), SnCl2-2H2O (208 g, 920 mmol), EtOAc (300 mL), and EtOH (150 mL) was heated to 80 °C and kept for 12 hours. After completion of the reaction, it was cooled to room temperature and the reaction mixture was poured into crushed ice (2 Kg) and the pH was adjusted to 7-8 with solid NaHCO3. The solid was collected by filtration and washed with EtOAc. The filtrate was extracted three times with EtOAc. The organic extracts were combined, washed with brine, dried over anhydrous Na2SO4, filtered and concentrated in vacuum. The crude product was purified by silica gel column chromatography using EtOAc/hexane gradient elution (10% to 50% EtOAc) to afford 28 g (91% yield) of 4-bromo-3-methyl-1,2-phenylenediamine as a brown oil. Mass spectrum (ESI) m/z = 202 [M + 1]+.

[1] Patent: WO2013/26914, 2013, A1. Location in patent: Page/Page column 143
[2] Patent: US2010/222345, 2010, A1. Location in patent: Page/Page column 87