'One-pot' process for the preparation of arylacrylic acids and their esters

摘要

A "one-pot" process for the palladium catalyzed coupling of a diazonium salt with an olefinic bond, in the aqueous medium in which the diazonium salt is made, by employing a carboxylic acid as a solvent, is described. Arylacrylic acids and their esters, e.g. the cinnamates, can be produced at low catalyst concentration without first isolating the diazonium salt. The process is in particular applied to the synthesis of 2-ethylhexyl p-methoxycinnamate.