Potassium Carbonate → (E)-3-[4-(2-phenylethenyl)-1,2,3,6-tetrahydropyridin-1-yl]methylbenzo[b]furan

Participants

Reaction Steps

Thionyl chloride (0.25 ml, 3.4 mmol) was added to a solution of 3-hydroxymethylbenzo[b]furan (0.4515 g, 3.05 mmol) in anhydrous ether (10 ml), the mixture was stirred at room temperature for 2.5 hours and evaporated to dryness. The residue was dissolved in anhydrous dimethylformamide (10 ml), potassium carbonate (1.05 g, 7.60 mmol) and (E)-4-(2-phenylethenyl)-1,2,3,6-tetrahydropyridine (0.68 g, 3.67 mmol) was added and the mixture stirred at room temperature, under nitrogen, overnight (20 hours). The reaction mixture was poured into water (100 ml) and extracted with ethyl acetate (2×50 ml). The extracts were washed with saturated brine (50 ml), combined and dried (magnesium sulfate). The residue after evaporation of the solvent was purified by flash chromatography, eluting with 20% then 25% ethyl acetate/petrol (60°-80°), to afford the title compound (0.4734 g, 49%). Recrystallisation from ethyl acetate/petrol (60°-80°) gave pale yellow needles, m.p. 122°-123° C.; (Found: C, 8.29; H, 6.58; N, 4.36. C22H21NO.0.1H2O requires C, 83.30; H, 6.74; N, 4.42%); δH (CDCl3) 2.43 (2H, br s, tetrahydropyridinyl CH2), 2.73 (2H, t, J 5.7Hz, tetrahydropyridinyl CH2), 3.21 (2H, d, J 2.7Hz, tetrahydropyridinyl CH2), 3.76 (2H, s, ArCH2N), 5.82 (1H, br s, tetrahydropyridinyl CH), 6.44 (1H, d, J 16.1Hz, CH=CHPh), 6.79 (1H, d, J 16.1Hz, CH=CHPh), 7.17-7.32 (5H, m, ArH), 7.39 (2H, m, ArH), 7.48 (1H, m, ArH), 7.58 (1H, s, 2-H), 7.73 (1H, m, ArH); m/z (ES+) 316 (M+1)+.

Provenance & Evidence