反应详情

To a mixed solution of 25 ml of concentrated hydrochloric acid and 15 g of ice were added 3.83 g (30,0 mmol) of p-chloroaniline (purchased from Tokyo Kasei), 7 ml of a 30% aqueous solution of sodium nitrite (purchased from Wako Junyaku Kogyo) in order, and the mixture was stirred at room temperature for 1 hour. A saturated aqueous solution of sodium acetate (purchased from Wako Junyaku Kogyo) was added to the mixture to adjust its pH to 4, insoluble materials were filtrated, the filtrate was added to a suspension of 5.77 g (30.0 mmol) of 4-methylesculetin (purchased from Tokyo Kasei) in 90 ml of acetone, 0.8 g of cupric chloride dihydrate (purchased from Kanto Kagaku) was further added thereto, and the mixture was stirred for 1 hour. The resultant mixture was concentrated under reduced pressure, most of the solvent was removed, 300 ml of ethyl acetate was added to the residue and mixed, insoluble material (unreacted 4-methylesculetin) was filtrated, an organic layer was separated, the water layer was extracted with ethyl acetate twice, the combined organic layer was washed with brine and dried over anhydrous magnesium sulfate, the solvent was removed under reduced pressure, the residue was purified according to column chromatography on silica gel (ethyl acetate:hexane=1:1 as an eluent), the effluent fraction containing an objective compound was allowed to stand, and the precipitate was collected and dried to give 533 mg (yield: 5.9%) of 3-(4-chlorophenyl)-4-methyl-6,7-dihydroxycoumarin (as a light yellow crystalline) represented by the following formula 35b: ##STR159##

1. filtrationwere filtrated
2. additionwas further added
3. stirringthe mixture was stirred for 1 hour
4. concentrationThe resultant mixture was concentrated under reduced pressure, most of the solvent
5. customwas removed
6. addition300 ml of ethyl acetate was added to the residue
7. additionmixed
8. filtrationinsoluble material (unreacted 4-methylesculetin) was filtrated
9. customan organic layer was separated
10. extractionthe water layer was extracted with ethyl acetate twice
11. washthe combined organic layer was washed with brine
12. dry with materialdried over anhydrous magnesium sulfate
13. customthe solvent was removed under reduced pressure
14. customthe residue was purified
15. additionhexane=1:1 as an eluent), the effluent fraction containing an objective compound
16. customthe precipitate was collected
17. customdried