Lawesson's reagent → 6-Pyridin-3-yl-3,4-dihydroquinoline-2(1H)-thione

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Reaction Steps

A mixture of 6-Pyridin-3-yl-3,4-dihydro-1H-quinolin-2-one (395 mg, 1.76 mmol) and Lawessons reagent (356 mg, 0.88 mmol) was refluxed in 30 ml toluene for 2 h. After evaporation of the solvent under reduced pressure, the residue was purified by flash chromatography on silica gel (hexanes/ethyl acetate, 3/7, Rf=0.31) which gave 6-Pyridin-3-yl-3,4-dihydro-1H-quinoline-2-thione as yellow plates (63 mg, 0.26 mmol, 15%), mp (hexanes/ethyl acetate) 267° C. 1H-NMR (500 MHz, DMSO-d6): δ=2.87 (m, 2H), 2.97 (m, 2H), 7.20 (d, 3J=8.2 Hz, 1H), 7.46 (dd, 3J=7.9 Hz, 3J=4.6 Hz, 1H), 7.59 (dd, 3J=8.2 Hz, 4J=1.9 Hz, 1H), 7.62 (d, 4J=1.9 Hz, 1H), 8.04 (m, 1H), 8.53 (dd, 3J=4.7 Hz, 4J=1.6 Hz, 1H), 8.87 (d, 4J=2.2 Hz, 1H), 12.30 (s, 1H). MS m/z=241.05 (MH+).

Provenance & Evidence