Patent ID: 6518455
Filing Date: 2003-02-11
Classification: C07C

Abstract:
A process for preparing substituted aromatic and heteroaromatic aldehydes or carboxylic acids of the formula in which R1 and R2 are H, C1-C4 alkyl, C1-C4 alkoxy, OH, NO2, CN, COOH, CONH2, COOR, NH2, SO3H or halogen and R is C1-C4 alkyl and where R1 and R2 are not simultaneously H, X is C or N and Z is CHO or COOH, which comprises dissolving a corresponding symmetric stilbene compound of the formula in which R1, R2 and X are as defined above either directly or as a salt in water and reacting it at a temperature of from 0 to +100Â° C. with ozone, giving a mixture comprising the corresponding aldehyde of the formula I and hydroperoxide from whicha) after acidic or alkaline decomposition of the hydroperoxide, the corresponding aldehyde of the formula I is isolated, or which b) is directly reacted, under acidic or alkaline decomposition of the hydroperoxide and with addition of an oxidizing agent, to give the corresponding carboxylic acid of the formula I or its salt, which is then isolated.