反应详情

Di-tert-butyl dicarbonate (3.5 g, 16 mmol) and triethylamine (13 ml, 9.4 mmol) were added to a stirred solution of 4-aminomethylphenylboronic acid (3 g, 16 mmol) in tetrahydrofuran (100 ml). The reaction was stirred under reflux for 1 hour, then the solvent evaporated and the residue partitioned between water and ethyl acetate. The organic phase was concentrated under reduced pressure to give tert-butoxycarbonylaminomethyl-4-phenyl-boronic acid (2.67 g, 10.6 mmol) as a white solid. Toluene (16 ml), ethanol (4 ml), 2M sodium carbonate solution and tetrakis(triphenylphosphine) palladium (0) were added to tert-butoxycarbonylaminomethyl-4-phenyl-boronic acid (1.349 g, 5.4 mmol) and 3-bromo-5-fluoro-2-methoxy-pyridine (0.505 g, 2.45 mmol) and the mixture stirred under reflux for 24 h. Water was added and the mixture extracted with ethyl acetate. The organic phase was separated and the solvent evaporated. The residue was purified on silica gel eluting with 3:1 heptane/ethyl acetate to give [4-(5-fluoro-2-methoxy-pyridin-3-yl-benzyl]-carbamic acid-tert-butyl ester as a yellow oil. Trifluoroacetic acid (2 ml, 0.026 mmol) was added to a solution of [4-(5-fluoro-2-methoxy-pyridin-3-yl-benzyl]-carbamic acid-tert-butyl ester (0.8 g, 2.41 mmol) in dichloromethane (4 ml) and the reaction mixture stirred for 2 h. The solvent was evaporated and the residue partitioned between water and ethyl acetate. The organic phase was separated and the solvent evaporated to give 4-(5-fluoro-2-methoxy-pyridin-3-yl)-benzylamine. The title compound was prepared in a similar manner to N-[1-(2-allyl-5′-fluoro-2′-methoxy-biphenyl-4-yl)-ethyl]-3,4-difluoro-benzenesulfonamide (Example 34) using 4-(5-fluoro-2-methoxy-pyridin-3-yl)-benzylamine and 3,5-dimethyl-isoxazole-4-sulfonyl chloride. MS (ESI) m/z: 392 [M+H]+.