Ethanol → 9-Oxo-9H-xanthene-3-carboxylic acid

Participants

Reaction Steps

A sample of 9-Oxo-9H-xanthene-3-carboxylic acid methyl ester, compound 4a, (16.6 g, 65.3 mmol) was suspended in 250 mL of 3 N NaOH and 250 mL of EtOH and heated to reflux for 1 h. At that time the EtOH was evaporated and the reaction was poured into 6 N HCl over ice and extracted with large volumes of 1:1 THF/diethyl ether. The combined organic phases were washed with brine, dried over magnesium sulfate, filtered and evaporated to provide 13.35 g of Compound 5a (55.6 mmol) after drying in a vacuum oven at 50° C. overnight.

Provenance & Evidence