Hydroxy and alkoxy aromatic aldehyde prepn. - by oxidn. of phenyl glycolic acid deriv. by air or oxygen in presence of copper catalyst

摘要

Prepn. of hydroxy and alkoxy aromatic aldehydes of formula (I) (where R1-2 are each H or 1-6C alkyl) by oxidn. of a phenylglycolic acid (II) by air or O2, in acid medium at 100 degrees C and 1-10 atmos. pressure, in the presence of a catalyst comprising an (in)organic Cu cpd. opt. mixed with an (in)organic iron. (I) are used directly or as intermediates in the pharmaceutical, cosmetic, food and chemical (e.g. prepn. of anti-oxidants) industries e.g. typical examples of (I) are vanillen, ethyl-vanillin, protocatechuic aldehyde, ortho- and para-hydroxy-benzaldehyde, veratric and aldehyde, pipersonal. The process gives high yields by a simple process using oxygen/air as an economic oxidant.