Pivaloyl chloride → (S)-5-[(biphenyl-4-yl)methyl]-1-(2,2-dimethylpropionyl)pyrrolidin-2-one

Participants

Reaction Conditions

Reaction Steps

20 g of (S)-5-biphenyl-4-ylmethylpyrrolidin-2-one (1-a, R1=H) of example 3 were dissolved in 200 ml tetrahydrofuran. The mixture was cooled to about −78° C. and 55 ml n-butyllithium (1.6 M) were added. After about 0.5 hours, 11.8 ml of pivaloyl chloride were added. After 1 hour, the mixture was quenched with 210 ml ammonium chloride solution and extracted with 70 ml ethyl acetate. The mixture was concentrated to dryness to obtain 26.7 g of (S)-5-biphenyl-4-ylmethyl-1-(2,2-dimethylpropionyl)pyrrolidin-2-one (1, R1=pivaloyl). 1H-NMR (CDCl3): 1.40 (9H, s, C(CH3)3); 1.91 (1H, m, 4-CHH); 2.03 (1H, m, 4-CHH); 2.47 (1H, m, 3-CHH); 2.55 (1H, m, 3-CHH); 2.74 (1H, dd, 1-CHH); 3.18 (1H, dd, 1-CHH); 4.67 (1H, m, 5-CH); 7.34 (2H, m, aromatic); 7.36 (1H, m, aromatic); 7.46 (2H, m, aromatic); 7.58 (4H, m, aromatic). m/z: 336 (MH+, 100%).

Provenance & Evidence