Acrylonitrile → 3-{2-[(E)-2-(2-Chlorophenyl)ethenyl]-5-methoxy-1H-indol-1-yl}propanenitrile

Participants

Reaction Steps

To a solution of trans-diene (27) prepared as described in example 37 (1.5 g, 5.25 mmol) in acetonitrile (30 mL) was added acrylonitrile (2.42 mL, 36.8 mmol) and 1,8-diazabicyclo[5,4,0]undec-7-ene (20 drops). The resulting solution was stirred at room temperature under nitrogen for 18 h before being diluted with water and extracted with ethyl acetate. The organic layer was dried, the drying agent was removed and the solution was concentrated to dryness. Chromatography on silica eluting with ethyl acetate/hexane (1:1), followed by trituration from methanol gave the diene (236) (1.36 g, 77%) as an off-white solid, mp 136–138° C. 1H NMR δ [(CD3)2SO] 8.05 (dd, J=7.9, 1.5 Hz, 1H), 7.50 (m, 4H), 7.41 (m, 1H), 7.33 (m, 1H), 7.04 (d, J=2.4 Hz, 1H), 6.90 (s, 1H), 6.81 (dd, J=9.0, 2.4 Hz, 1H), 4.68 (t, J=6.6 Hz, 2H), 3.77 (s, 3H), 2.93 (t, J=6.6 Hz, 2H). Found: C, 71.32; H, 5.14; N, 8.51. C20H17ClN2O requires: C, 71.31; H, 5.09; N, 8.31.

Provenance & Evidence