反应详情

温度

85 °C

49.8 mg of methyl N-hydroxymethyl-N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]carbamate [prepared as described in Example 19] were dissolved in 2 ml of butanol at room temperature, and the pH of the resulting solution was adjusted with concentrated sulfuric acid to pH 3. A catalytic amount of hydroquinone (2 mg) was added to the resulting mixture at room temperature and the mixture was then stirred for 1 hour at 85° C. The reaction mixture was then cooled to room temperature, diluted with aqueous sodium hydrogen sulfate and then extracted with ethyl acetate. The resulting extract was washed with a saturated aqueous sodium chloride solution and then dried over anhydrous sodium sulfate. The solvent was removed by evaporation under reduced pressure to give a residue which was purified by column chromatography through silica gel using a 2:1 by volume mixture of hexane and ethyl acetate as the eluent, to give 702.5 mg (yield 94.1%) of the title compound as an oil.

1. temperatureThe reaction mixture was then cooled to room temperature
2. extractionextracted with ethyl acetate
3. extractionThe resulting extract
4. washwas washed with a saturated aqueous sodium chloride solution
5. dry with materialdried over anhydrous sodium sulfate
6. customThe solvent was removed by evaporation under reduced pressure
7. customto give a residue which
8. customwas purified by column chromatography through silica gel using a 2:1
9. additionby volume mixture of hexane and ethyl acetate as the eluent