1-Ethyl-4-(4-nitro-2-(trifluoromethyl)benzyl)piperazine (21.7 g, 68.3 mmol) was used as starting material, which was dissolved in methanol and stirred thoroughly. Pd/C catalyst (1.8 g, 17.08 mmol) was added to the reaction system and the reaction was stirred at room temperature under hydrogen atmosphere for about 12 hours. Upon completion of the reaction, the reaction mixture was filtered through a diatomite pad under reduced pressure and the diatomite pad was washed with methanol. The filtrate was collected and concentrated under reduced pressure to afford the target product 4-(4-ethylpiperazine-1-methyl)-3-trifluoromethylaniline (19.4 g, 99% yield). The product was confirmed by NMR hydrogen spectrum (300 MHz, DMSO-d6): δ 7.30 (d, 1H), 6.85 (s, 1H), 6.76 (d, 1H), 5.42 (s, 2H), 3.37 (s, 2H), 2.33 (m, 10H), 1.01 (t, 3H). Mass spectrometry analysis (ESI+, m/z): 288 [M+H]+.
