PREPARATION OF CARBOXYLIC ACIDS AND ESTERS THEREOF

摘要

A carboxylic acid or an ester thereof having at least two carbon atoms more than formic acid is prepared by reacting at elevated temperature e.g. 100 DEG to 250 DEG C. formic acid or a formate ester with an olefin e.g. ethylene in the presence of, as catalyst, a Group VIII noble metal e.g. iridium, preferably promoted by iodide, to cause addition of the formic acid or ester to the olefin and form the a higher acid e.g. propionic acid or ester thereof. A strong acid such as a sulphonic acid may be used as a copromoter. The catalyst is employed in solution.