Phenylglyoxylic acid


Phenylglyoxylic acid is the organic compound with the formula C6H5CCO2H. The conjugate base, known as benzoylformate is the substrate of benzoylformate decarboxylase, a thiamine diphosphate-dependent enzyme:
It is a colourless solid with a melting point of 64–66 °C and is moderately acidic.
Phenylglyoxylic acid can be synthesized by oxidation of mandelic acid with potassium permanganate. An alternative synthesis involves hydrolysis of benzoyl cyanide.