反应详情

Sodium hydride (prepared by washing 553 mg of 65% sodium hydride with absolute n-hexane) is suspended in 15 ml of dimethylformamide. A solution of 3.4 g of 2-benzoyl-1-cyano-5,7-dibenzyloxy-1,2-dihydroisoquinoline in 40 ml of dimethylformamide is added dropwise to the suspension at -10° C in a nitrogen atmosphere. Then, a solution of 1.71 g of 3,4,5-trimethoxybenzyl chloride in 40 ml of dimethylformamide is added dropwise to the mixture for 30 minutes, and the mixture is allowed to stand at the same temperature for 30 minutes. The reaction mixture is poured into ice-water, and extracted with ethyl acetate. The extract is evaporated to remove solvent, whereby 2-benzoyl-1-cyano-5,7-dibenzyloxy-1-(3,4,5-trimethoxybenzyl)-1,2-dihydroisoquinoline is obtained as a crude oil. The crude oil is dissolved in 200 ml of dioxane. 50 ml of an aqueous 10% sodium hydroxide solution are added to the dioxane solution, and this mixture is stirred at 50° C for 12 hours. After the reaction, the mixture is evaporated under reduced pressure to remove solvent. The residue thus obtained is extracted with methylene chloride. The methylene chloride extract is washed with water, dried and then evaporated to remove solvent. 3.1 g of 5,7-dibenzyloxy-1-(3,4,5-trimethoxybenzyl)-isoquinoline are obtained as a crude product. Yield: 84% M.p. 158° - 160° C (recrystallized from ethanol).

1. extractionextracted with ethyl acetate
2. customThe extract is evaporated
3. customto remove solvent