Process for the preparation of pyrrole-2-acetic acids, their nitriles and esters

摘要

Pyrrole-2-acetic acid esters and nitriles of the respective formulae <IMAGE> and <IMAGE> are prepared by subjecting a pyrrolidene-malonic acid derivative of the formula II <IMAGE> to catalytic dehydrogenation, preferably using dehydrogenation catalysts which contain, or consist of, palladium, platinum or rhodium. In the above formulae, X and Y independently of one another denote groups of the formulae -COO(lower alkyl) or -CN, and R1 and R2 independently of one another denote hydrogen atoms or lower alkyl radicals. The esters nitriles obtained can be hydrolysed to give the corresponding pyrrole-2-acetic acid. The products obtained may be used, for example, to prepare corresponding 5-aroyl-pyrrole-2-acetic acid derivatives, which are effective anti-inflammatory agents.