88002-33-9

56406-73-6

88002-33-9

The general procedure for the synthesis of [1,2,4]triazolo[1,5-a]pyrazin-2-amines from the compound (CAS: 56406-73-6) is as follows: Example 270b Synthesis of [1,2,4]triazolo[1,5-a]pyrazin-2-amine 270b: In a 250 mL single-necked round-bottomed flask equipped with a magnetic stirrer and a reflux condenser, 270a (6.00 g, 26.43 mmol, 1.0 equiv), hydroxylamine hydrochloride (3.32 g, 47.52 mmol, 1.8 equiv), N,N-diisopropylethylamine (DIPEA, 12 mL), ethanol (40 mL), and methanol (40 mL) were added. The reaction mixture was stirred at 65 °C for 16 hours. Upon completion of the reaction, the mixture was cooled to room temperature and concentrated under reduced pressure to about 20 mL. The resulting suspension was collected by filtration and the solid was washed with dichloromethane/ethanol (60:1, 50 mL) to give 270b (3.3 g, 92% yield) as a white solid. Mass spectrum (MS-ESI): [M + H]+ m/z 136.3. 1H NMR (500 MHz, DMSO-d6) δ 8.84 (d, J = 1.0 Hz, 1H), 8.70 (dd, J = 1.0, 4.0 Hz, 1H), 7.98 (d, J = 5.0 Hz, 1H), 6.47 (s, 2H).