Diisopropylethylamine → 3-[2(R)-Triethylsiloxypropyl]amino-3-methyl-N-[2,3,4,5-tetrahydro-2-oxo-1H-1-benzazepin-3(R)-yl]-butanamide

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Reaction Steps

To a stirred solution of 660 mg (1.48 mmol) of the intermediate obtained in Step B in 3 mL of methylene chloride at room temperature was added 1.1 mL of N,N-diisopropylethylamine (0.81 g, 4.2 eq.) followed by 0.71 mL of triethylsilyl trifluoromethanesulfonate (0.83 g, 2.1 eq.). The resulting mixture was stirred at room temperature for 2 hours then partitioned between ethyl acetate and saturated aqueous sodium chloride (buffered to pH 9 with 2 drops of ammonium hydroxide). The organic layer was separated, washed with buffered brine, dried over magnesium sulfate, filtered and solvents evaporated under vacuum. The residue was purified by preparative high pressure liquid chromatography on silica, eluting with ethyl acetate/0.1% ammonium hydroxide in methanol (85:15), to afford 480 mg (1.07 mmol, 72%) of product. 1H NMR (200 MHz,CD3OD): 0.63 (q,8 Hz,6H), 0.97 (t,8 Hz,9H), 1.14 (s,6H), 1.18 (d,6 Hz,3H), 2.05 (m,1H), 2.28 (d,2Hz,2H), 2.35-3.00 (m,5H), 4.01 (m,1H), 4.44 (dd;8,12 Hz;1H), 7.05 (d,8 Hz,1H), 7.10-7.35 (m,3H). FAB-MS: calculated for C24H41N3O3Si 447; found 448 (M+H, 100%).

Provenance & Evidence