反应详情

温度

20 °C

To a suspension of 95.3 g of 2-formyl-3,5-dimethoxy-6-methylbenzoic acid methyl ester in 250 ml of dichloromethane were added 800 ml of a 1M solution of boron trichloride in dichloromethane over 40 min at a temperature of 5°-10° C. The mixture was allowed to warm to 20° C. within 30 min and stirring was continued at room temperature for 4 h. The clear solution was cooled to 5° C. and then poured into a mixture of 1.5 I of ice-water and 0.5 l of dichloromethane. The layers were separated and the aqueous phase was back-extracted with 0.4 l of dichloromethane. The organic layers were washed with water, dried over sodium sulfate and evaporated in vacuo. Crystallization of the residual material from ethyl acetate/hexane provided 77.3 g of 2-formyl-3-hydroxy-5-methoxy-6-methylbenzoic acid methyl ester as colorless crystals of m.p. 118°-119° C.

1. temperatureThe clear solution was cooled to 5° C.
2. customThe layers were separated
3. extractionthe aqueous phase was back-extracted with 0.4 l of dichloromethane
4. washThe organic layers were washed with water
5. dry with materialdried over sodium sulfate
6. customevaporated in vacuo
7. customCrystallization of the residual material from ethyl acetate/hexane