反应详情

A solution of (S)-5-(1-methylpyrrolidin-2-yl)-1,4-dihydropyridine-3-carbaldehyde IV (0.011 g, 0.044 mmol) and elemental sulfur (0.0015 g, 0.044 mmol) in 2 mL of toluene was refluxed for 1 day. After filtration through a pad of Celite, and evaporation of the solvent under reduced pressure, the crude material was purified by RPLC (silica gel, 5% EtOAc/hexanes then EtOAc) to afford 0.007 g (83%) of 5-(1-methylpyrrolidin-2-yl)pyridine-3-carbaldehyde V as a clear oil. IR (thin film, neat, NaCl): 2950, 1586, 1370, 1120 cm−1. 1H NMR (CDCl3, 300 MHz) δ 10.13-10.12 (m, 1 H), 8.97-8.96 (m, 1 H), 8.79 (s, 1 H), 8.18 (s, 1 H), 3.30-3.20 (m, 2 H), 2.38-1.67 (m, 4 H); 13C NMR (CDCl3, 100 MHz) δ 191.26, 154.81, 150.91, 135.13, 131.69, 68.53, 57.19, 40.64, 40.64, 35.66, 23.02. HRMS Calcd for C11H14N2O: 191.1184 [M+H]+. Found: 191.1182 [M+H]+. [α]23D −92 (c=0.2, CH2Cl2).

1. filtrationAfter filtration
2. customthrough a pad of Celite, and evaporation of the solvent under reduced pressure
3. customthe crude material was purified by RPLC (silica gel, 5% EtOAc/hexanes