反应详情

A mixture of 4-(5-formyl-2,4-dimethyl-pyridin-3-yloxymethyl)-benzonitrile (23) (0.40 g, 1.5 mmol), 4-amino-4′-cyanobiphenyl (0.35 g, 1.8 mmol) and p-toluenesulfonic acid monohydrate (0.08 g, 0.45 mmol) was heated at 100° C. in benzene (15 mL) under nitrogen atmosphere with a Dean-Stark condenser for 18 hours. The solvent mixture was then evaporated and the crude product dissolved in methyl alcohol (20 mL), and to the solution was added sodium borohydride (0.56 g, 15 mmol). The reaction mixture was stirred at room temperature for 2 hours, quenched with saturated aqueous sodium bicarbonate, extracted with ethyl acetate and then back washed with water. The combined organic layer was dried over anhydrous magnesium sulfate, filtered and evaporated to dryness. The crude product was purified by column chromatography on silica gel using a gradient mixture of ethyl acetate:hexane (0:1 to 1:1) as eluant to give 4′-{[5-(4-cyano-benzyloxy)-4,6-dimethyl-pyridin-3-ylmethyl]-amino}-biphenyl-4-carbonitrile (24) (266 mg, 40% overall yield for two steps).

1. customThe solvent mixture was then evaporated
2. dissolutionthe crude product dissolved in methyl alcohol (20 mL)
3. customquenched with saturated aqueous sodium bicarbonate
4. extractionextracted with ethyl acetate
5. washback washed with water
6. dry with materialThe combined organic layer was dried over anhydrous magnesium sulfate
7. filtrationfiltered
8. customevaporated to dryness
9. customThe crude product was purified by column chromatography on silica gel using
10. additiona gradient mixture of ethyl acetate:hexane (0:1 to 1:1) as eluant