反应详情

To a stirred suspension of hydroxylamine hydrochloride (about 17 g) and N,N-diisopropylethylamine (about 26 mL) in a mixture of methanol (about 70 mL) and ethanol (about 70 mL) is added N-(3-bromo-2-pyridinyl)-N′-carboethoxy-thiourea. The mixture is stirred for about 2 hours at room temperature then heated to about 60° C. for about 18 hours. The suspension is cooled to room temperature, filtered and rinsed with methanol, water then methanol. 8-Bromo-[1,2,4]triazolo[1,5-a]pyridin-2-ylamine is isolated as an off-white solid (about 8 g). 1H NMR (400 MHz, (D3C)2SO, δ, ppm): 8.58 (d, J=6.4 Hz, 1H), 7.73 (d, J=7.6 Hz, 1H), 6.80 (t, J=7.0 Hz, 1H), 6.25 (s, 2H). MS=213, 215 (MH)+.

1. temperaturethen heated to about 60° C. for about 18 hours
2. temperatureThe suspension is cooled to room temperature
3. filtrationfiltered
4. washrinsed with methanol, water