Ethylene Glycol → 3-(4-cyanobenzoyl)indolizine

Participants

Reaction Steps

A solution of 1-acetyl-3-(4-cyanobenzoyl)indolizine (12) (1.56 grams, 5.69 mmol), ethylene glycol (1 mL), and p-toluenesulfonic acid (2.16 grams, 11.38 mmol) in benzene (150 mL) was refluxed for 3 hours. The reaction mixture was cooled to room temperature, neutralized with saturated sodium bicarbonate solution and extracted with ethyl acetate (3×50 mL). The combined layers were concentrated in vacuo. Purification by flash column chromatography (Rf 0.3, ethyl acetate in hexane) afforded 3-(4-cyanobenzoyl)indolizine (13) as a light yellow solid (1.12 grams, 80%). 1H NMR (CDCl3) δ 6.56 (d, J=4.8, 1H), 7.04 (t, J=6.9, 1H), 7.28 (m, 2H), 7.61 (d, J=9.0, 1H), 7.78 (m, 2H), 7.89 (m, 2H), 9.98 (d, J=7.2, 1H). ESMS calcd (C16H10N2O2): 246.1. found: 247.1 (M+H)+.

Provenance & Evidence