反应详情

5.0 g of 4-(o-fluorobenzoyl)-5-methoxybenzocyclobutene-1-carboxylic acid methyl ester are dissolved in 100 ml of dichloromethane; 6.4 g of aluminium trichloride are added and the whole is heated at boiling for 4 hours while stirring. The mixture is poured onto ice; 20 ml of concentrated hydrochloric acid are added and the whole is extracted by shaking twice with 100 ml of dichloromethane each time. The organic phases are combined, washed with water, dried over magnesium sulphate and concentrated to dryness by evaporation. The residue is chromatographed over silica gel and recrystallised from ether/hexane. 4-(o-fluorobenzoyl)-5-hydroxybenzocyclobutene-1-carboxylic acid methyl ester is obtained having a melting point of 72°-73°.

1. temperaturethe whole is heated
2. additionThe mixture is poured onto ice
3. extractionthe whole is extracted
4. stirringby shaking twice with 100 ml of dichloromethane each time
5. washwashed with water
6. dry with materialdried over magnesium sulphate
7. concentrationconcentrated to dryness by evaporation
8. customThe residue is chromatographed over silica gel
9. customrecrystallised from ether/hexane