Hexane → N-[2-(2-methylamino-2-phenylethyl)phenyl]-2,2-dimethylpropanamide

Participants

Reaction Steps

A stirred solution of N-[(2-methyl)phenyl]-2,2-dimethylpropanamide (95.6 g, 0.5 mol) in THF (500 ml, dried over 4 Å molecular sieves) was cooled to 0° C. and treated with 1.6M n-butyllithium in hexane (630 ml, 1.0 mol). The addition of n-butyllithium was complete after 45 minutes. During the addition, the temperature of the mixture was maintained below 10° C. with external cooling. The resultant dianion solution was aged (about 1-2 hrs) at 0° C. until the homogeneous orange solution became a white heterogeneous slurry. The dianion was then quenched with N-benzylidenemethylamine (63.7 g, 0.6 mol) and aged for 30 minutes at 15°-25° C. The reaction mixture was diluted with ether (200 ml), treated with crushed ice (200 g), and stirred for 15 minutes. The organic phase was separated, washed with saturated sodium chloride, dried over anhydrous magnesium sulfate and concentrated in vacuo. The residual oil was crystallized from hexane (400 ml) at 5° C. to give N-[2-(2-methylamino-2-phenylethyl)phenyl]-2,2-dimethylpropanamide (121.2 g, 0.39 mol) in 78% yield. The product had a melting point of 85°-86° C.

Provenance & Evidence