[Synthesis]
General procedure for the synthesis of 1-methyl-2-nitro-4-(trifluoromethyl)benzene from 4-methyltrifluorotoluene: Referring to Example 10, 4-methyltrifluorotoluene (18.6 g, 116 mmol) was dissolved in concentrated sulfuric acid (120 ml), and a concentrated sulfuric acid solution (60 ml) of potassium nitrate (12.9 g, 128 mmol) was added slowly by dropwise addition, and the dropping process was controlled to be completed in 15 The titration process was controlled to be completed within 15 minutes and room temperature was maintained. After the dropwise addition, the reaction mixture was stirred at the same temperature for 2 hours. After completion of the reaction, the mixture was slowly poured into ice water and extracted with ethyl acetate, the organic phase was dried with anhydrous sodium sulfate and the solvent was subsequently removed by distillation. The crude product obtained was purified by silica gel column chromatography with an eluent ratio of hexane:ethyl acetate=8:1, resulting in 22.8 g of the target product 1-methyl-2-nitro-4-(trifluoromethyl)benzene as a pale yellow liquid in 96% yield. The structure of the product was confirmed by 1H-NMR (CDCl3, δ): 2.69 (3H, s), 7.52 (1H, d, J=8.3 Hz), 7.76 (1H, d, J=8.3 Hz), 8.25 (1H, s). |