반응 #502090

반응 방정식

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

용매

EtOH MeOH

반응 조건

후처리

1. 1
   온도the mixture slowly heated
2. 2
   온도to reflux
3. 3
   기타(Note: bleach scrubber is required to quench H2S evolved)
4. 4
   온도After 3 h at reflux
5. 5
   온도to cool
6. 6
   여과filtered
7. 7
   기타to collect the precipitated solid
8. 8
   여과Further product is collected by evaporation in vacuo of the filtrate, addition of H2O (250 mL) and filtration
9. 9
   세척The combined solids are washed successively with H2O (250 mL), EtOH/MeOH (1:1, 250 mL) and Et2O (250 mL)
10. 10
    기타then dried in vacuo

실험 절차

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%).

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