Methanol → 3-Methoxyxanthone

Participants

Reaction Steps

A solution of the benzophenone intermediate (12.51 g) in EtOH (200 ml) was treated with a solution of NaOMe in MeOH (25 wt. %, 22.86 ml, 0.1 mole) at room temperature, the color of the mixture changed from yellow to orange immediately. The reaction mixture was brought to reflux for 100 min. Cooled to 0°, the reaction mixture was treated with water (100 ml), to produce a fine white precipitate. The solid was filtered on a Buchner funnel, washed with water and EtOH, and finally dried in vacuo, yielding 3-methoxy-9H-xanthen-9-one 8 (9.12 g, 80.7%) as a white powder: m.p. 127-129° C.; 1H NMR (CDCl3): delta 8.31 (1H, dd, J=7.9, 1.2 Hz), 8.23 (1H, J=8.6 Hz), 7.68 (1H, m), 7.44 (1H, d, J=8.6 Hz), 7.35 (1H, m), 6.93 (1H, m), 6.87 (1H, d, J=2.4 Hz) and 3.92 (3H, s); 1R (CHCl3): 2999, 1644, 1605, 1460, 1434, 1321, 1273, 1254, 1159, 1101, 1029, 968 and 848 cm-1.

Provenance & Evidence