Lawesson's reagent → ethyl 2-(7-(2,5-dimethyl-1H-pyrrol-1-yl)-2-thioxo-3,4-dihydroquinolin-1(2H)-yl)propanoate

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Reaction Steps

A solution of ethyl 2-(7-(2,5-dimethyl-1H-pyrrol-1-yl)-2-oxo-3,4-dihydroquinolin-1(2H)-yl)propanoate (1.6 g, 4.70 mmol) and Lawesson reagent (1.9 g, 4.70 mmol) in toluene (20 mL) was heated to reflux for 2 h. The reaction mixture was cooled to ambient temperature and the mixture was concentrated in vacuo. The residue was purified by column chromatography on silica gel (eluting with 0-5% EtOAc in petroleum ether) to give ethyl 2-(7-(2,5-dimethyl-1H-pyrrol-1-yl)-2-thioxo-3,4-dihydroquinolin-1(2H)-yl)propanoate (0.20 g, 12%). 1H NMR (CDCl3, 400 MHz): δ 7.27 (d, J=8.0 Hz, 1H), 6.94 (d, J=8.06 Hz, 1H), 6.82 (s, 1H), 6.58 (m, 1H), 5.91 (s, 2H), 4.13 (q, J=7.2 Hz, 2H), 3.24 (m, 2H), 2.85 (m, 2H), 2.03 (s, 6H), 1.71 (d, J=7.2 Hz, 3H), 1.13 (t, J=7.2 Hz, 3H).

Provenance & Evidence