反応 #1172666

反応方程式

4-chromanol

benzene

4-toluenesulfonic acid

→

benzopyran

溶媒

water

反応条件

後処理

1. 1
   その他(ca. 3 hrs.)
2. 2
   洗浄It was then washed successively with saturated NaHCO3 aqueous solution and water
3. 3
   乾燥dried over anhydrous MgSO4
4. 4
   その他evaporated under reduced pressure
5. 5
   その他to yield an almost colorless liquid which
6. 6
   workup.DISTILLATIONwas distilled under vacuum

実験手順

A mixture of 4-chromanol (30 g; 0.02 mole), benzene (200 ml) and 4-toluenesulfonic acid (200 mg) was refluxed, with a Dean-Stark trap, until separation of water ceased (ca. 3 hrs.). It was then washed successively with saturated NaHCO3 aqueous solution and water, dried over anhydrous MgSO4 and evaporated under reduced pressure to yield an almost colorless liquid which was distilled under vacuum to give benzopyran (20.2 g, 76.4%) b.p. 73°-78°/3 torr.

出典