反应详情

2,5-dimethylphenol (24.5 g, 0.2 mol) was dissolved in 125 ml of anhydrous ethanol. To the solution was added 75 ml of 21 wt % sodium ethoxide solution in ethanol (0.2 mol). The mixture solution was stirred at room temperature for 10 min. Ethyl 4-bromobutyrate (40 g, 0.205 mol) was then added to the solution. The reaction mixture was refluxed at 80° C. for 24 h. The precipitate was filtered off. The filtrate was then mixed with a solution of sodium hydroxide (10 g, 0.25 mol) in 150 ml of water. The mixture was stirred at 70° C. for about 2 hours, monitored with HPLC. It was diluted with 150 ml of water and acidified to pH 1. Oily precipitate formed immediately. It was collected by decanting the supernatant and washed with water twice (100 ml×2). The oily precipitate solidified after kept in water at room temperature overnight.

1. temperatureThe reaction mixture was refluxed at 80° C. for 24 h
2. filtrationThe precipitate was filtered off
3. stirringThe mixture was stirred at 70° C. for about 2 hours
4. customOily precipitate formed immediately
5. customIt was collected
6. customby decanting the supernatant
7. washwashed with water twice (100 ml×2)
8. waitafter kept in water at room temperature overnight