N-((1,1-dimethylethoxy)carbonyl)-beta-alanine → 3-t-Butoxycarbonylamino-N-[2,3,4,5-tetrahydro-2-oxo-1H-1-benzazepin-3-yl]-propanamide

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Reaction Steps

To a solution of 50 mg (0.28 mmol) 3-amino-2,3,4,5-tetrahydro-1H-1-benzazepin-2-one (Example 1; Step A) in 2 mL methylene chloride at room temperature was added 56 mg (0.30 mmol, 1.05 eq) 3-(t-butoxycarbonylamino)propanoic acid followed by 0.1 mL diisopropylethylamine (74 mg, 0.57 mmol, 2 eq) and 190 mg (0.43 mmol, 1.5 eq) benzotriazol-1-yloxytris(dimethylamino) phosphonium hexafluorophosphate. After 1 hour at room temperature, the mixture was added to 20 mL ethyl acetate and washed with 1M aqueous citric acid, saturated aqueous sodium bicarbonate and brine. The organic layer was removed, dried over magnesium sulfate, filtered and solvents removed in vacuo. The residue was purified by medium pressure liquid chromatography on silica, eluting with ethyl acetate/hexane (2:1) to afford 76 mg (0.22 mmol, 77%) of product as a white solid. 1H NMR (200 MHz, CDCl3): 1.40 (s,9H), 1.95 (m,1H), 2.40 (t,6 Hz,2H), 2.6-3.0 (m,3H), 3.36 (q,6 Hz, 2H), 4.52 (m,1H), 5.15 (br t,1H), 6.58 (br d,1H), 7.0-7.3 (m,4H), 7.6 (br s,1H). FAB-MS: calc. for C18H25N3O4 347; found 348 (M+H,35%).

Provenance & Evidence