Synthesis of Alkyl Glyoxylates

Glyoxylic acid esters are prepared using commercially available 50% w/w aqueous solution of glyoxylic acid. The method involves neutralization of aqueous solution of glyoxylic acid with sodium hydroxide followed by isolation of glyoxylic acid as a calcium salt by double decomposition technique. Suspending this calcium salt of glyoxylic acid in an alcohol and liberating free glyoxylic acid by concentrated sulfuric acid gives an alcoholic solution of glyoxylic acid containing insoluble anhydrous calcium sulfate. Glyoxylic acid being a strong acid readily forms an ester. The effect of various reaction parameters on overall conversion of glyoxylic acid and selectivity with respect to alkyl glyoxylate were studied.