反应 #502090

反应方程式

hydroxylamine hydrochloride

N,N-diisopropylethylamine

1-(6-Bromo-pyridin-2-yl)-3-carboethoxy-thiourea

→

triazolopyridine

5-Bromo-[1,2,4]triazolo[1,5-a]pyridin-2-ylamine

溶剂

EtOH MeOH

反应条件

后处理

1. 1
   温度the mixture slowly heated
2. 2
   温度to reflux
3. 3
   其他(Note: bleach scrubber is required to quench H2S evolved)
4. 4
   温度After 3 h at reflux
5. 5
   温度to cool
6. 6
   过滤filtered
7. 7
   其他to collect the precipitated solid
8. 8
   过滤Further product is collected by evaporation in vacuo of the filtrate, addition of H2O (250 mL) and filtration
9. 9
   洗涤The combined solids are washed successively with H2O (250 mL), EtOH/MeOH (1:1, 250 mL) and Et2O (250 mL)
10. 10
    其他then dried in vacuo

实验过程

To a suspension of hydroxylamine hydrochloride (101.8 g, 1.465 mol) in EtOH/MeOH (1:1, 900 mL) is added N,N-diisopropylethylamine (145.3 mL, 0.879 mol) and the mixture is stirred at room temp. (20° C.) for 1 h. 1-(6-Bromo-pyridin-2-yl)-3-carboethoxy-thiourea (2) (89.0 g, 0.293 mol) is then added and the mixture slowly heated to reflux (Note: bleach scrubber is required to quench H2S evolved). After 3 h at reflux, the mixture is allowed to cool and filtered to collect the precipitated solid. Further product is collected by evaporation in vacuo of the filtrate, addition of H2O (250 mL) and filtration. The combined solids are washed successively with H2O (250 mL), EtOH/MeOH (1:1, 250 mL) and Et2O (250 mL) then dried in vacuo to afford the triazolopyridine derivative (3) as a solid. The compound may be used as such for the next step without any purification. 1H (400 MHz, DMSO-d6) δ 7.43-7.34 (2H, m, 2×aromatic-H), 7.24 (1H, dd, J 6.8 and 1.8 Hz, aromatic-H), 6.30 (2H, br, NH2); m/z 213/215 (1:1, M+H+, 100%).

来源