2,3-Dihydroxybutanedioic Acid → 3-(S)-amino-1-ethoxycarbonylmethyl-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one tartrate salt

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Reaction Steps

Tartaric acid (12.6 g) and racemic 3-amino-1-ethoxycarbonylmethyl-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one (22 g) were dissolved in hot ethanol (200 ml). This solution was cooled and allowed to stand overnight at room temperature. The solid which precepitated was collected by filtration and recrystallized twice from ethanol (200 ml) to give 3-(S)-amino-1-ethoxycarbonylmethyl-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one tartrate salt. This was dissolved in H2O (100 ml) and the pH adjusted to 9 with dilute ammonium hydroxide and extracted with methylene chloride (2×50 ml). The combined extracts were washed with water (75 ml), dried (magnesium sulfate) and evaporated to give 3-(S)-amino-1-ethoxycarbonylmethyl-2,3,4,5-tetrahydro-1H -[1]benzazepin-2-one, m.p. 104°-106°, [α]D =-285.5° (c=0.99 in ethanol).

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