Phloroglucinol → 1,3-dihydroxy-5-methoxy-9H-xanthen-9-one

Participants

Reaction Conditions

Reaction Steps

2,3-dimethoxybenzoic acid (0.91 g, 5 mmol), phloroglucinol (0.95 g, 7.5 mmol), ZnCl□ (4.69 g, 30 mmol) and POCl□ (20 mL) were charged to a dry round-bottom flask, followed by stirring at 80° C. for 4 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and was very slowly added to 500 mL of ice water. When the reaction liquid was poured in ice water, ice was added portionwise to prevent overheating. The resulting precipitate was allowed to stand at 4° C. overnight, combined, washed with water and ether, and then dried under reduced pressure to give the title compound (1.22 g, 94.8%) as a reddish brown solid.

Provenance & Evidence