A solution of 222 mg (0.594 mmol) of 3-t-butoxycarbonyl-amino-3-methyl-N-[2,3,4,5-tetrahydro-2-oxo-1H-1-benzazepin-3(R)-yl]-butanamide (Step I) in 6 mL of dry dimethylformamide was treated with 30 mg of 60% sodium hydride oil dispersion (18 mg NaH, 0.75 mmol, 1.3 eq). The reaction mixture was stirred at room temperature for 30 minutes. To the solution was added 190 mg (0.594 mmol) of solid 4-bromomethyl-2'-(methoxycarbonyl)amino-1,1'-biphenyl. After stirring at room temperature for 1 hour, the reaction mixture was diluted with ethyl acetate followed by 50 mL of water. The organic layer was washed with water (4×), dried over magnesium sulfate, filtered and evaporated under vacuum. The residue was purified by preparative thin layer chromatography on silica gel, eluting with methylene chloride/methanol (100:3) to give 231 mg (0.376 mmol, 63%) of the product. 1H NMR (400 MHz, CDCl3): δ 1.23 (s, 3H), 1.33 (s, 3H), 1.39 (s, 9H), 1.85 (m, 1H), 2.40 (dd, 2H), 2.49 (m, 1H), 2.54 (m, 2H), 3.68 (s, 3H), 4.53 (m, 1H), 4.94 (d, 1H), 5.17 (d, 1H), 6.53 (br s, 1H), 6.66 (d, 1H), 7.2 (m, 12H), 8.09 (d, 1H).
