反应详情

Palladium on carbon (5%, 50 mg) was added to a solution of (E)-2-[[3-(3,4-dimethoxyphenyl)-1-oxo-2-propenyl]amino]benzoic acid (tranilast) (0.50 g, 1.5 mmol) in THF (9.0 mL), EtOH (1.0 mL) and AcOH (1 drop). The suspension was stirred under an atmosphere of hydrogen for 16 h and filtered. The filtrate was concentrated under reduced pressure and the crude product was recrystallised from EtOAc/petrol to give 2-[[3-(3,4-dimethoxyphenyl)-1-oxopropyl]amino]benzoic acid (0.39 g, 77%) as a colourless crystalline solid; mp 137° C., lit. [24] 136-137.5° C.; δH (500 MHz, DMSO-d6) 2.68 (t, J=7.5 Hz, 2H, CH2CO), 2.87 (t, J=7.5 Hz, 2H, CH2Ar), 3.68 (s, 3H, OCH3), 3.70 (5, 3H, OCH3), 6.74 (d, J5′,6′=8.2 Hz, 1H, H6′), 6.82 (d, J5′,6′=8.2 Hz, 1H, H5′), 6.86 (s, 1H, H2′), 7.12 (t, J3,4=J4,5=8.0 Hz, 1H, H4), 7.57 (t, J4,5=J5,6=8.0 Hz, 1H, H5), 7.95 (d, J3,4=8.0 Hz, 1H, H3), 8.47 (d, J5,6=8.0 Hz, 1H, H6), 11.11 (s, 1H, NH), 13.57 (br s, 1H, CO2H).

1. filtrationfiltered
2. concentrationThe filtrate was concentrated under reduced pressure
3. customthe crude product was recrystallised from EtOAc/petrol