Hydrochloric Acid → 1-benzyloxycarbonylmethyl-3-(1-carboxy-3-phenylpropylamino)-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one

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Reaction Steps

Sodium cyanoborohydride (0.152 g, 0.0014 mol) was added to a solution of 1-benzyloxycarbonylmethyl-3-amino-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one (0.45 g, 0.0014 mol) and benzylpyruvic acid (0.48 g, 0.0028 mol) in methanol (35 ml). The reaction mixture was stirred at room temperature under nitrogen for 2 hours. Additional benzylpyruvic acid (0.48 g, 0.0028 mol) was added, and the reaction mixture stirred for an additional 18 hours. Concentrated hydrochloric acid (0.5 ml) was added and the resulting solution stirred for 1 hour. The solvents were removed under reduced pressure and the residue treated with dichloromethane (100 ml) to precipitate sodium chloride. After filtration, the solvent was removed under reduced pressure and the residue chromatographed on silica gel (30 g). Elution with ethyl acetate/methanol/acetic acid (90:10:0.2) gave 1-benzyloxycarbonylmethyl-3-(1-carboxy-3-phenylpropylamino)-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one as an oil; NMR(CDCl3) 7.35 (m, 14H), 5.10 (s, 2H), 4.60(m, 2H), 3.00(m, 12H).

Provenance & Evidence