反应详情

A solution of 251 mg (1.00 mmole) of 5-chloro-6-(piperidin-1-yl)-benzofuran-2(3H)-one in 5 ml of absolute tetrahydrofuran is cooled to -78° under a nitrogen atmosphere, 0.84 ml (1.00 mmole) of a 20% diisobutyl aluminium hydride solution in toluene is added and the whole is stirred for 30 minutes at -78°. 2 ml of 2N sulphuric acid are then added and the whole is stirred for 15 minutes at -40°. The reaction mixture is diluted with water and extracted with methylene chloride. The organic phases are washed with water, combined, dried over sodium sulphate and concentrated in a vacuum rotary evaporator. 5-chloro-2-hydroxy-6-(piperidin-1-yl)-2,3-dihydrobenzofuran is obtained in the form of an oil which is used for the following reactions without purification. Rf [silica gel, chloroform/ethyl acetate (3:1)]=0.48.

1. stirringthe whole is stirred for 15 minutes at -40°
2. extractionextracted with methylene chloride
3. washThe organic phases are washed with water
4. dry with materialdried over sodium sulphate
5. concentrationconcentrated in a vacuum rotary evaporator