3,4,5-Trimethoxybenzoic Acid → N-Boc-pyrrolidine

Participants

Reaction Steps

To a solution of the compound 2-[2-(2-Methyl-3-phenyl-allylamino)-ethyl-pyrrolidine-1-carboxylic acid tert-butyl ester (prepared from racemic proline according to the scheme1), 0.6 g (2 mmol) and 3,4,5-trimethoxy benzoic acid 0.513 g (2.4 mmol) in dry dichloromethane 10 ml, triethyl amine 0.2 ml was added and stirred at room temperature for 20 min. Then was added O-(benzotriazole-1-yl)-N,N,N′,N′-tetramethyl uranium tetrafluoroborate 1.3 g (4 mmol) at 0° C. The reaction mixture was stirred at room temperature overnight. The reaction mixture was diluted with DCM and was washed with 10% NaHCO3 solution, water and brine, dried, concentrated and subjected to column chromatography silica gel using CHCl3/MeOH as eluent to obtain 1 g of 2-{2-[(2-Methyl-3-phenyl-allyl)-3,4,5-trimethoxy-benzoyl)-amino]-ethyl}-pyrrolidine-1-carboxylic acid tert-butyl ester.

Provenance & Evidence