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

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)+.

1. customprepared
2. temperatureThe reaction mixture was refluxed under nitrogen for 30 minutes
3. temperatureThe reaction mixture was refluxed overnight
4. customthe precipitate removed by filtration
5. customthe solvent removed in vacuo
6. additionConcentrated hydrochloric acid (800 mL) was added to the residue
7. temperaturethe reaction mixture was refluxed for 14 hours
8. washThe cooled aqueous solution was washed with ether (2×200 mL)
9. customThe residual ether in the aqueous phase was removed by nitrogen bubbling through the solution
10. additionThe pH of the aqueous phase was adjusted to 7-8 by the addition of ammonium hydroxide
11. filtrationThe title compound was collected by filtration, air
12. customdried
13. customrecrystallized from ethanol-water
14. customto afford 150 g (83%)

ORD record

ord-417210cd9dde4cd5aba04604f3e02108

Source dataset

uspto-grants-1997_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05663148