Triethylamine → tert-Butyl 4-(2-methoxy-2-oxo-1-phenylethyl)piperazine-1-carboxylate

Participants

Reaction Steps

To a solution of racemic α-bromophenylacetic acid methyl ester, 5.0 g (22.0 mmol) in 200 mL of tetrahydrofuran was added 3.4 mL (22.0 mmol) of Et3N and 12.3 g (66.0 mmol) of BOC-piperazine. The reaction mixture was refluxed for 3.5 hours, cooled to rt. and concentrated to dryness. The residue was partitioned between 20% isopropanol/chloroform and water. The mixture was washed with saturated NaHCO3, washed with brine, dried over Na2SO4, filtered and concentrated to dryness. The residue was purified by chromatography using chloroform as eluent and was concentrated to dryness to yield 7.73 g (100%) of the desired mixture of isomers as a colorless oil.

Provenance & Evidence