Water → 1,5-Bis(3,4,5-trimethoxyphenyl)penta-1,4-dien-3-one

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Reaction Steps

3-(N,N,N-trimethylammonio)-1-(3,4,5-trimethoxyphenyl)propan-1-one iodide (355.9 g, 0.87 mole) was suspended in a mixture of water (3.56 L) and of ethyl acetate (2.54 L) and refluxed with rapid stirring for 2-3 hours. The mixture was cooled and the pale yellow organic layer was removed. Fresh ethyl acetate (2 L) was added and the mixture was refluxed for 1 hour, and the process was repeated once again. The organic layers were combined, washed with brine, dried over anhydrous MgSO4, and evaporated to dryness to provide a yellow oil, which was crystallized from hexane/ether to give 3,4,5-trimethoxyphenylvinyl ketone (m.p. 45°-47° C.). 200 MHz 1H NMR (CDCl3): δ 3.94 (9H, s, 3 OCH3), 5.92 (1H, dd, J=1.5 Hz, J=9 Hz), 6.44 (1H, dd, J=1.5 Hz, J=1.5 Hz, J=16 Hz), 7.18 (1H, dd, J=16 Hz, J=9 Hz), 7.28 (2H, H2 and H6).

Provenance & Evidence