Reaktion #2062

Reaktionsgleichung

5,6,7,8-tetrahydro-2-(5-acetyloxy-2,4-dichlorophenyl)-1,2,4-triazolo[4,3-α]pyridin-3(2H)-one

N-bromosuccinimide

→

title product

Ausbeute 93.6%

5,6,7,8-tetrahydro-2-(5-acetyloxy-2,4-dichlorophenyl)-8-bromo1,2,4-triazolo[4,3-α]pyridin-3(2H)-one

Ausbeute 93.6%

Lösungsmittel

carbon tetrachloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was warmed
2. 2
   Temperaturunder reflux
3. 3
   Sonstigeby irradiating with a sun lamp for 3h
4. 4
   Einengenconcentrated under reduced pressure
5. 5
   SonstigeThe crude product was purified by flash chromatography over silica gel
6. 6
   Wascheneluting with a 1:1 v
7. 7
   workup.ADDITIONv mixture of ethyl acetate and n-hexane

Vorschrift

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).

Quelle