反应详情

A mixture of 3.32 parts of 6,8-di-t-butyl-2,3-dihydro-4-oxo-4H-1-benzopyran-2-carboxylic acid, ethyl ester and 3.33 parts of selenium dioxide was refluxed in 35 parts of xlene for eight hours. The reaction mixture was cooled, ether was added and the insoluble inorganic products were removed by filtration. Evaporation of the volatile components of the filtrate gave a brown residue which crystallised from light petroleum (b.p. 40°-60°C) to give 1.54 parts of 6,8-di-t-butyl-4-oxo-4H-1-benzopyran-2-carboxylic acid, ethyl ester, m.p. 130°-131.5°C.

1. temperaturewas refluxed in 35 parts of xlene for eight hours
2. temperatureThe reaction mixture was cooled
3. customthe insoluble inorganic products were removed by filtration
4. customEvaporation of the volatile components of the filtrate
5. customgave a brown residue which
6. customcrystallised from light petroleum (b.p. 40°-60°C)