PROCESS FOR PREPARING ARYL AND HETEROARYL HEXADIENOIC ACIDS

摘要

A process for preparing aryl- and heteroarylhexadienoic acids is herein described and claimed, which is characterized in that an aryl- or heteroarylacetylene having the formula: R-C IDENTICAL CH, wherein R is an aryl or heteroaryl group, optionally substituted and having in the aggregate up to 20 carbon atoms, is reacted with 3-butenoic acid CH2=CH-CH2-COOH, in an alcoholic medium, at temperatures staying between 50 DEG C and 120 DEG C approximately, in the presence of a catalyst selected from amongst the phoshinic complexes of rhodium having the formulas:
Rh(PR min 3)n LmX associated with alkaline salts of carboxylic (III) acids having up to 4 carbon atoms, and Rh(PR min 3)nLp<+>Y<-> (IV),
where R is a hydrocarbyl group having up to 12 carbon atoms;
<> is a linear or cyclic olefin selected from amongst the olefins having a number of carbon atoms of from 2 to 10 and the chelating olefins having from 6 to 8 carbon atoms, n is an integer from 1 to 3, m is an integer from 0 to 2 and such that n + m = 2 or 3, and p is an integer from 0 to 3 and such that n + p = 3 or 4; X is an anion selected from among the haloid ones, preferably it is the hydrochloric one, and the anions of carboxylic acids having up to 4 carbon atoms and Y is a sparingly coordinating anion, preferably selected from PF6<-> and BF4<->. The compounds obtained are used as intermediates for organic syntheses.