Methanesulfonic acid, 1,1,1-trifluoro-, calcium salt (2:1) → trans-3-[4-(4-Chloro-phenyl)-[1,4]diazepan-1-yl]4-hydroxy-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-(4-Chloro-phenyl)-[1,4]diazepane (1.00 g, 4.80 mmol) in acetonitrile (10 mL) was added 6-Oxa-3-aza-bicyclo[3.1.0]hexane-3-carboxylic acid tert-butyl ester (0.925 g, 5.00 mmol) and Calcium(II) trifluoromethanesulfonate (0.676 g, 2.00 mmol). The solution was stirred at 80° C. for 17 hours under nitrogen atmosphere. The reaction was concentrated in vacuo. The residue was diluted with saturated aqueous sodium bicarbonate (50 mL) and extracted with ethyl acetate (3×30 mL). The combined organics were washed with brine, dried over MgSO4, and evaporated. The residue was purified by silica gel chromatography (ethyl acetate→87:10:3 ethyl acetate:methanol:triethylamine) to yield 0.819 g (41%) of the title compound. ESI-MS m/z: 396 (M+1), FAS method rt: 1.25 min.

Provenance & Evidence