Acetic Acid → 4-Biphenyl-2-ylmethyl-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of biphenyl-2-carbaldehyde (5.01 g, 27.5 mmol) in dichloromethane (150 ml) at rt under nitrogen was added piperazine-1-carboxylic acid tert-butyl ester (5.63 g, 30.2 mmol) followed by glacial acetic acid (1.90 ml, 33.2 mmol). The reaction was stirred for 1 h before sodium triacetoxyborohydride (11.65 g, 55.0 mmol) was introduced. After 3 h, a solution of 5% NaOH (˜15 ml) was added and the mixture was extracted with dichloromethane. The organic layer was separated, washed with H2O (×2), brine, dried (Na2SO4), filtered and concentrated under reduced pressure to give 4-biphenyl-2-ylmethyl-piperazine-1-carboxylic acid tert-butyl ester as an oil (9.9 g, 100%) which was used without further purification. HPLC-MS 353 [M+1]+.

Provenance & Evidence