Phloroglucinol → 1,3-dihydroxy-12H-benzo(b)xanthen-12-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 3-hydroxy-2-naphthoic acid (2.0 g, 10.63 mmol), phloroglucinol (1.34 g, 10.63 mmol), ZnCl2 (3.30 g, 24.24 mmol) and POCl3 (40 mL) was stirred under reflux at 80° C. for 5 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and was very slowly added to 1 L of ice water. The resulting solid was allowed to stand (1 d), filtered, washed with water, and then dried under reduced pressure to obtain an ocherous compound. This compound was separated and purified by silica gel column chromatography (developing solvent: ethyl acetate:n-hexane=1:3 (v/v)) to give the title compound (289 mg, 9.8%) as a yellow solid.

Provenance & Evidence