Ammonia → 4-(2-Methyl-pentyl)-pyrrolidin-2-one

Participants

Reaction Conditions

Reaction Steps

A 250 mL 3-neck flask equipped with a dry ice condenser was chilled to −78° C. Ammonia (80 mL) was condensed into the flask and 1-benzyl-4-(2-methyl-pentyl)-pyrrolidin-2-one 76 (1.67 g, 0.006 mol) in 15 mL THF was added. Freshly cut sodium beads were added until a deep blue color persisted. The cooling bath was removed and the reaction stirred at reflux (−33° C.) for 1 hour. The reaction was quenched with ammonium chloride and the excess ammonia was allowed to evaporate. The resulting residue was diluted with water, extracted with dichloromethane, and dried over magnesium sulfate. Evaporation of the solvent followed by chromatography on silica eluting with 1:1 acetone/hexane gave 0.94 g, 86% of the 4-(2-Methyl-pentyl)-pyrrolidin-2-one 77. 1H NMR (CDCl3) δ 6.25 (br, 1H), 3.44 (m, 1H), 2.95 (m, 1H), 2.54 (m, 1H), 2.40 (m, 1H), 1.98 (m, 1H), 1.30 (m, 6H), 0.80 (m, 6H). MS, m/z (relative intensity): 212 [M+2H+CH3CN, 100%], 171 [M+2H, 72%], 170 [M+1H, 65%].

Provenance & Evidence