Ammonia → 3-(Phenylmethyl)-2-piperidinone

Participants

Reaction Steps

A solution of 1,3-diphenylmethyl-2-piperidinone (2.79 g, 10 mmol) in dry THF (25 mL) was added at -78° C. to a well stirred solution of Li metal (0.70 g, 100 mmol) in liquid NH3 (200 mL). After 15 min, the cooling bath was removed, and the NH3 was allowed to escape (ca. 2 h). The resulting colorless residue was treated with saturated NH4Cl (50 mL), and extracted with EtOAc (3×50 mL). The combined organic extract was washed with brine (25 mL), dried over MgSO4, and concentrated in vacuo to give 2.78 g of brown viscous residue. Flash chromatography over silica gel (1% MeOH in CHCl3 -EtOAc, 1:1) afforded the lactam (See: Rodrequez M, Heitz A, Martinez J (1992) supra)(0.87 g, 46% ) as a colorless solid: mp 120-122° C. (CH2Cl2 -hexanes).

Provenance & Evidence