Water → 6'-methoxy-5',7'-dimethyl-1'H-spiro[cyclobutane-1,2'-quinolin]-4'(3'H)-one

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Reaction Steps

To a solution of 2-(1-(4-methoxy-3,5-dimethylphenylamino)cyclobutyl)acetic acid (650 mg) in 10 mL toluene was added a large excess of polyphosphoric acid. The mixture was refluxed for 30 minutes, water was added, and the solution was extracted with ethyl acetate (3×20 mL). The combined organic layers were dried over Na2SO4 and the solvent was removed by evaporation, giving 6′-methoxy-5′,7′-dimethyl-1′H-spiro[cyclobutane-1,2′-quinolin]-4′(3′H)-one as a yellow solid (1 g). 1H-NMR (300 MHz, CDCl3) δ=6.25 (s, 1H), 2.78 (s, 2H), 2.55 (s, 3H), 2.125-2.38 (m, 5H), 1.95-2.06 (m, 2H), 1.73-1.83 (m, 2H) ppm. MS: m/z 246 (100, M+H)+

Provenance & Evidence