Magnesium → 2-[(3,4-Dichloro-5-fluoro-phenyl)-hydroxy-methyl]-2-propyl-pyrrolidine-1-carboxylic acid tert-butyl ester

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Reaction Conditions

Reaction Steps

A stirred mixture of 3,4-dichloro-5-fluorophenyl bromide (1.38 g, 5.66 mmol) and magnesium turnings (0.145 g, 5.94 mmol) in THF (8 mL) was heated at reflux under nitrogen for 30 minutes, then cooled to 0° C. To the reaction mixture was added a solution of 2-formyl-2-propyl-pyrrolidine-1-carboxylic acid tert-butyl ester (0.682 g, 2.38 mmol) in THF (2 mL) dropwise over 15 minutes. The cold reaction mixture was stirred for one hour, then quenched by the addition of saturated aqueous NH4Cl (20 mL) and extracted with EtOAc. The combined organic extracts were washed with brine, dried (MgSO4), filtered and concentrated in vacuo to a yellow oil (1.7 g). Purification by chromatography (silica, 0 to 20% EtOAc in hexanes) gave 2-[(3,4-dichloro-5-fluoro-phenyl)-hydroxy-methyl]-2-propyl-pyrrolidine-1-carboxylic acid tert-butyl ester (0.571 g, 1.41 mmol, 50%) as a white solid.

Provenance & Evidence