Benzophenone, 2,2',5-trimethoxy- → 2-Hydroxyxanthone

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Reaction Steps

A mixture of crude 2,2',5-trimethoxybenzophenone (22.6 g, 83 mmol) prepared as described above, and pyridine hydrochloride (121 g, 1.04 mol) was refluxed (~210° C.) for 10 hours under N2. The mixture was then poured into ice water (350 g), and the resultant yellow-green precipitate was collected by filtration and washed with water (2×100 mL), and 6 N aqueous HCl (3×100 mL), and dried in vacuo. Yield: 14.1 g (80%). TLC: Rf 0.54 [benzene-EtOH (20:3)]. m.p. 245°-246° C. NMR data in accordance with structure. ##STR4##

Provenance & Evidence