Hexamethylphosphoramide → 2-(3-Nitro-3-phenyl-propyl)-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a −78° C. solution of 200 mg (1.460 mmol) 2-(2-bromo-ethyl)-pyrrolidine-1-car boxylic acid tert-butyl ester (CAS: 958026-65-8) in 4.3 ml tetrahydrofuran over mol-sieves and 851.0 ul HMPA, was added drop-wise 1.92 ml (3.064 mmol) n-BuLi (1.6 M in hexane). After 45 minutes at −78° C., a solution of 406.2 mg (1.460 mmol) nitromethyl-benzene in 0.6 ml tetrahydrofuran over mol-sieves was added drop-wise. After 1 hour at −78° C., the reaction mixture was allowed to warm up slowly (during 5 hours) to −2° C. The mixture was then cooled again to −78° C. and quenched at this temperature with 0.4 ml of acetic acid, then with 8 ml saturated ammonium chloride. Back to room temperature, the aqueous phase was extracted 2 times with ethylacetate. The combined organic layers were washed with brine, dried over sodium sulfate, filtered and concentrated in vacuo. The crude yellow oil (993 mg) was purified with flash column chromatography on silica eluting from n-heptane and ethyl acetate (0 to 15%) to provide 242 mg (y: 49.6%) of the title compound as a colorless oil. MS (m/e): 335.2 (M+H+).

Provenance & Evidence