反应详情

A solution of 2.9g of 3-(3,4-dihydroxybenzoyl)-benzoic acid in 100 ml of methanol is mixed with 7g of Amberlyst 15® and refluxed with stirring for 8 hours. The reaction mixture is filtered on diatomaceous earth, the filtrate concentrated by evaporation, taken up in ethyl acetate and shaken out with 10% sodium bicarbonate solution. The organic phase is dried on sodium sulfate and concentrated by evaporation. 1.4g of 3-(3,4-dihydroxybenzoyl)-benzoic acid methyl ester is obtained as oily crude product. 272 mg of this crude product is dissolved in 2.5 ml of dimethylformamide, mixed with 269 mg of (1E)-6-bromo-l-(4-methoxyphenyl)-1-hexene and 185 mg of lithium carbonate and the mixture is heated for 18 hours to 50°-60° C. with stirring. The reaction mixture is filtered, washed with dichloromethane, the filtrate is concentrated by evaporation and the residue is chromatographed on silica gel with hexane/ethyl acetate=98/2. 230 mg of 3-[3-hydroxy- 4-[6-(4-methoxyphenyl)-(5E)-5-hexenyloxy]benzoyl]-benzoic acid methyl ester is obtained as oil.

1. temperaturerefluxed
2. filtrationThe reaction mixture is filtered on diatomaceous earth
3. concentrationthe filtrate concentrated by evaporation
4. stirringshaken out with 10% sodium bicarbonate solution
5. customThe organic phase is dried on sodium sulfate
6. concentrationconcentrated by evaporation