反应详情

To a solution of 3.55 g (10.4 mmol) of 5,6,7,8-tetrahydro-2-(5-acetyloxy-2,4-dichlorophenyl)-1,2,4-triazolo[4,3-α]pyridin-3(2H)-one in 100 mL of carbon tetrachloride was added 2.03 g (11.4 mmol) of N-bromosuccinimide at room temperature. The mixture was warmed under reflux by irradiating with a sun lamp for 3h. The mixture was cooled to room temperature and concentrated under reduced pressure. The crude product was purified by flash chromatography over silica gel, eluting with a 1:1 v:v mixture of ethyl acetate and n-hexane to give 4.10 g of the title product of Step 1 as a white solid, m.p.: 75°-83° C.; 1H NMR (CDCl3, 300 MHz) δ 7.6 (s,1H), 7.35 (s,1H), 5.25 (m,1H), 4.0 (m,1H), 3.6 (m,1H), 2.75 (s,3H), 2.5-1.9 (m,4H).

1. temperatureThe mixture was warmed
2. temperatureunder reflux
3. customby irradiating with a sun lamp for 3h
4. concentrationconcentrated under reduced pressure
5. customThe crude product was purified by flash chromatography over silica gel
6. washeluting with a 1:1 v
7. additionv mixture of ethyl acetate and n-hexane