Formaldehyde → (S)-5-biphenyl-4-ylmethyl-1-pyrrolidin-1-ylmethylpyrrolidin-2-one

Participants

Reaction Steps

A mixture of 500 mg (S)-5-biphenyl-4-ylmethylpyrrolidin-2-one (1-a, R1=H), 329 μl pyrrolidine and 415 μl formaldehyde in 3.5 ml ethanol were heated at reflux for 3 h. A further quantity of 164 μl pyrrolidine and 148 μl formaldehyde were added and the mixture refluxed for about 24 h. The mixture was concentrated to dryness and purified by chromatography to obtain 533 mg of (S)-5-biphenyl-4-ylmethyl-1-pyrrolidin-1-ylmethylpyrrolidin-2-one (1-a, R1=methylpyrrolidin). 1H NMR (DMSO): 1.69 (4H, m, 2×NCH2CH2); 1.68-2.15 (4H, m, 3-CH2, 4-CH2); 2.50 (4H, 2×NCH2); 2.66 (1H, dd, 1-CHH); 3.12 (1H, dd, 1-CHH); 3.94 (1H, d, NCHHN); 4.21 (1H, d, NCHHN); 7.29 (2H, d, aromatic); 7.33 (1H, t, aromatic); 7.44 (2H, t, aromatic); 7.59 (2H, d, aromatic); 7.64 (2H, d, aromatic). m/z: 335 (MH+, 100%)

Provenance & Evidence