反应详情

1.78 g (8.12 mmol) of 2,8-dimethyl-5-nitro-4H-chromen-4-one are heated with 9.16 g (40.6 mmol) of tin(II) chloride dihydrate in 70 ml of ethyl acetate at 70° C. overnight. After cooling to room temperature, the reaction mixture is brought to pH 9-10 with saturated sodium bicarbonate solution. After filtration through kieselguhr, the organic phase is separated off, and the aqueous phase is extracted several times with ethyl acetate. The combined organic phases are washed with saturated sodium chloride solution. After drying over sodium sulfate, the solvent is removed in vacuo. 1.5 g (99% of theory) of the title compound are obtained.

1. filtrationAfter filtration through kieselguhr
2. customthe organic phase is separated off
3. extractionthe aqueous phase is extracted several times with ethyl acetate
4. washThe combined organic phases are washed with saturated sodium chloride solution
5. dry with materialAfter drying over sodium sulfate
6. customthe solvent is removed in vacuo