Ethanol → 9-Oxo-9H-xanthene-3-carboxylic acid
Reaction equation
C[O:2][C:3]([C:5]1[CH:6]=[CH:7][C:8]2[C:9](=[O:19])[C:10]3[C:15]([O:16][C:17]=2[CH:18]=1)=[CH:14][CH:13]=[CH:12][CH:11]=3)=[O:4].CCO>[OH-].[Na+]>[O:19]=[C:9]1[C:8]2[CH:7]=[CH:6][C:5]([C:3]([OH:4])=[O:2])=[CH:18][C:17]=2[O:16][C:15]2[C:10]1=[CH:11][CH:12]=[CH:13][CH:14]=2Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
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.