General procedure for the synthesis of 2-amino-5-trifluoromethylpyrazine from 2-chloro-5-trifluoromethylpyrazine: 2-chloro-5-(trifluoromethyl)pyrazine (5.0 g, 27 mmol) was mixed with ammonium hydroxide (190 mL, 2.7 mol) and the reaction was stirred for 3.5 h at 80 °C in a sealed pressure vessel. After completion of the reaction, it was cooled to room temperature and the reaction mixture was extracted with dichloromethane (4×). The organic phases were combined, dried over anhydrous sodium sulfate, filtered and concentrated to give 2-amino-5-trifluoromethylpyrazine (4.0 g, 90% yield) as a white solid. The product was confirmed by 1H NMR (400 MHz, CDCl3): δ 8.34 (s, 1H), 8.01 (s, 1H), 5.01 (br s, 2H).The LCMS analysis showed that the calculated value of [M+H]+ m/z was 164.0, and the measured value was 164.1, which was in agreement with the target compound.
