反应详情

To a solution of 4′-Benzyloxy-biphenyl-3-carboxylic acid ethyl ester (2.3 g) in ethanol/ethyl acetate (3:1) (200 mL) is added 5% palladium on carbon (300 mg). The reaction mixture is placed under an atmosphere of hydrogen (55 psi) and is shaken on a Parr apparatus for 2 h. Concentrated hydrochloric acid (0.3 mL) is added to the reaction mixture. The reaction mixture is allowed to proceed for an additional 10 h. Trifluoroacetic acid (1 mL) and 20% palladium hydroxide on carbon (300 mg) are added to the reaction mixture and the reaction is allowed to stir under an atmosphere of hydrogen (60 psi). After an additional 80 h, the reaction mixture is degassed with nitrogen and is filtered though a plug of silica gel, eluting with 500 mL ethyl acetate and 500 mL ethanol. The filtrate is concentrated under reduced pressure and the residue is diluted with 400 mL saturated sodium bicarbonate solution. The product is extracted three times with methylene chloride. The combined organic layers are dried over magnesium sulfate, filtered, and concentrated under reduced pressure to afford the title compound (1.6 g, 95%) as a white solid.

1. waitto proceed for an additional 10 h
2. stirringto stir under an atmosphere of hydrogen (60 psi)
3. waitAfter an additional 80 h
4. customthe reaction mixture is degassed with nitrogen
5. filtrationis filtered though a plug of silica gel
6. washeluting with 500 mL ethyl acetate and 500 mL ethanol
7. concentrationThe filtrate is concentrated under reduced pressure
8. additionthe residue is diluted with 400 mL saturated sodium bicarbonate solution
9. extractionThe product is extracted three times with methylene chloride
10. dry with materialThe combined organic layers are dried over magnesium sulfate
11. filtrationfiltered
12. concentrationconcentrated under reduced pressure