Butyl iodide → 2-Butyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester

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Reaction Conditions

Reaction Steps

To a stirred solution of pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (3.00 g, 13.1 mmol) in THF (50 mL) at −78° C. and under nitrogen was added LHMDS (14.4 mL of 1.0 M solution in THF, 14.4 mmol) dropwise. After 30 minutes, a solution of 1-iodobutane (2.23 mL, 19.7 mmol) in THF (1 mL) was added dropwise. The reaction mixture was stirred for 30 minutes at −78° C., warmed to ambient temperature over 90 minutes, then quenched by the addition of saturated aqueous NH4Cl and extracted with EtOAc. The combined extracts were washed with saturated aqueous NaHCO3 and brine then dried (MgSO4), filtered and concentrated in vacuo to a yellow oil (4.5 g). Purification by chromatography (silica, 10% EtOAc in hexanes) gave 2-butyl-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (2.57 g, 9.01 mmol, 69%) as a clear colourless oil.

Provenance & Evidence