(3-Bromopropyl)benzene → 2-Amino-5-phenylpentanoic acid

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Reaction Steps

Diethyl acetamidomalonate (220 g) in 1 L of absolute ethanol was added to a stirred solution of sodium ethoxide in ethanol, prepared by dissolving sodium (24 g) in absolute ethanol (500 mL), under nitrogen. The reaction mixture was refluxed under nitrogen for 30 minutes and then 1-bromo-3-phenylpropane (200 g) was added. The reaction mixture was refluxed overnight, cooled to ambient temperature, the precipitate removed by filtration and the solvent removed in vacuo. Concentrated hydrochloric acid (800 mL) was added to the residue and the reaction mixture was refluxed for 14 hours. The cooled aqueous solution was washed with ether (2×200 mL). The residual ether in the aqueous phase was removed by nitrogen bubbling through the solution. The pH of the aqueous phase was adjusted to 7-8 by the addition of ammonium hydroxide. The title compound was collected by filtration, air dried and recrystallized from ethanol-water to afford 150 g (83%). m.p. 255°-257° C. MS (FAB) m/e 194 (M+H)+.

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