Synthesis and Crystal Structure of 4-(Bis(4-hydroxy-2-oxo-2H-chromen-3-yl)methyl)benzoic Acid

The structure of 4-(bis(4-hydroxy-2-oxo-2H-chromen-3-yl)methyl)benzoic acid (1) was determined by X-ray crystallography. Compound 1 · THF crystallizes in the monoclinic system, space group P21/n (#14) with cell parameters a = 10.676(2)Å, b = 10.017(2)Å, c = 24.438(6)Å, β = 100.890(10)°, V = 2566.4(10)Å3 and Z = 4. The molecular configuration/conformation is stabilized by two intramolecular hydrogen bonds formed between the carbonyl group of one 4-hydroxycoumarin unit and the hydroxyl group of the second one and the opposite (C=O···H–O).