p-Toluenesulfonic acid → 7-(2,5-dimethyl-pyrrol-1-yl)-3,4-dihydro-1H-quinolin-2-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 7-amino-3,4-dihydroquinolin-2(1H)-one (3.0 g, 18.50 mmol), hexane-2,5-dione (3.0 g, 25.9 mmol) and 4-methylbenzenesulfonic acid (3.2 g, 18.50 mmol) in toluene (40 mL) was stirred at 100° C. for 30 min. The reaction mixture was cooled to ambient temperature, concentrated in vacuo and the residue was purified by flash column chromatography on silica gel (eluting with 10% EtOAc in petroleum ether) to give 7-(2,5-dimethyl-pyrrol-1-yl)-3,4-dihydro-1H-quinolin-2-one (3.0 g, 67%). 1H NMR (CDCl3, 400 MHz): δ 8.72 (brs, 1H), 7.23 (d, J=8.0 Hz, 1H), 6.83 (d, J=8.0 Hz, 1H), 6.67 (s, 1H), 5.89 (s, 2H), 3.02 (t, J=8.0 Hz, 2H), 2.68 (m, 2H), 2.03 (s, 6H).

Provenance & Evidence