General procedure for the synthesis of 2-bromo-1-isopropyl-4-nitrobenzene from 1-isopropyl-4-nitrobenzene: A mixed solution of 1-isopropyl-4-nitrobenzene (50 g, 0.300 mol, GC purity: 99.1%) and ferric chloride (III) was heated to 40 °C and bromine (59.92 g, 0.375 mol) was added slowly and dropwise over a period of 3 hours. After completion of the reaction, the reaction mixture was poured into 120 ml of water and a 40% concentration of aqueous sodium bisulfite (20.81 g, 0.078 mol) was added dropwise. Subsequently, the mixture was extracted with 100 ml of chlorobenzene. After separating the organic phase, the chlorobenzene phase was washed with 100 ml of 5% concentration aqueous HCl solution. Finally, the chlorobenzene was evaporated under reduced pressure to afford 2-bromo-1-isopropyl-4-nitrobenzene (74.05 g, GC purity: 96.9%, yield: 98% of the theoretical value), the product was a yellow oily substance. 1H-NMR (600 MHz, CDCl3) data were as follows: δ= 8.41 (d, 1H), 8.14 (dd, 1H), 7.45 (d, 1H ), 3.45 (heptet, 1H), 1.29 (d, 3H), 1.27 (d, 3H) ppm. GC-MS analysis: m/z = 245 [M+].
