反应详情

A solution of 1.4 g (5.2 mmole) of 5-chloro-3-hydroxy-3-methyl-6-(piperidin-1-yl)-2,3-dihydrobenzofuran in 20 ml of acetic acid/5N hydrochloric acid 1:1 is maintained at 85° for one hour. The reaction mixture is concentrated in a vacuum rotary evaporator, water is added to the residue and the whole is adjusted to pH 7 with saturated sodium carbonate solution and extracted with methylene chloride. The organic phases are washed with water, combined, dried over sodium sulphate and concentrated in a vacuum rotary evaporator. Chromatography over silica gel using chloroform as eluant yields 5-chloro-3-methyl-6-(piperidin-1-yl)-benzofuran which, after recrystallisation from petroleum ether, melts at 82°-84°.

1. concentrationThe reaction mixture is concentrated in a vacuum rotary evaporator, water
2. additionis added to the residue
3. extractionextracted with methylene chloride
4. washThe organic phases are washed with water
5. dry with materialdried over sodium sulphate
6. concentrationconcentrated in a vacuum rotary evaporator