反应详情

温度

0 °C

Pyridine (150 ml) was added to 40 g (160 mmol) of 3,4-dihydro-2-(2-hydroxyethyl)-6-methoxy-2,5,7,8-tetramethyl-2H-benzopyran for dissolution of the latter. Then the solution was cooled to 0° C. and thereto was added with vigorous stirring 34.5 g of p-toluenesulfonyl chloride gradually. After stirring at 0° C. for 1 hour, the reaction mixture was poured into 1 liter of dilute hydrochloric acid and extracted with diethyl ether. The ether layer was washed with water, dried over anhydrous magnesium sulfate and filtered. After removal of low-boiling substances from the filtrate by distillation, the residue was purified by silica gel column chromatography to give 49.8 g (78.6% yield) of 3,4-dihydro-6-methoxy-2-[2-(p-toluenesulfonyloxy)ethyl]-2,5,7,8-tetramethyl-2H-benzopyran, which has the following FD mass spectrum.

1. additionwas added
2. extractionextracted with diethyl ether
3. washThe ether layer was washed with water
4. dry with materialdried over anhydrous magnesium sulfate
5. filtrationfiltered
6. customAfter removal of low-boiling substances from the filtrate
7. distillationby distillation
8. customthe residue was purified by silica gel column chromatography