反応 #90752

反応方程式

ethyl 2-thioxopiperidine-4-carboxylate

2,2,2-trifluoroacetohydrazide

→

ethyl 3-(trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridine-7-carboxylate

収率 88.9%

溶媒

THF

反応条件

後処理

1. 1
   温度heated at 60° C. for overnight
2. 2
   ろ過filtered
3. 3
   その他Removed the solvent under reduced pressure
4. 4
   濃縮the filtrate was concentrated
5. 5
   その他purified by silica gel column chromatography (PE/EA=3/1)

実験手順

To a solution of ethyl 2-thioxopiperidine-4-carboxylate (5.7 g, 14.95 mmol) in THF (203 mL) was added 2,2,2-trifluoroacetohydrazide (7.8 g, 60.88 mmol) and Hg(OAc)2 (10.71 g, 33.48 mmol) at ice-water. The mixture was stirred at room temperature for 2 hours and heated at 60° C. for overnight, then filtered. Removed the solvent under reduced pressure and the filtrate was concentrated and purified by silica gel column chromatography (PE/EA=3/1) to afford ethyl 3-(trifluoromethyl)-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-a]pyridine-7-carboxylate (3.5 g, yield 43.8%). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 1.10-1.32 (m, 3H) 2.16 (br. s., 1H) 2.36 (br. s., 1H) 2.93 (br. s., 1H) 3.02-3.39 (m, 2H) 3.90-4.30 (m, 4H).

出典