Patent ID: 6162928
Filing Date: 2000-12-19
Classification: B01J,C07D

Abstract:
A process for preparing pyrroles of the formula I: ##STR5## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are identical or different and are hydrogen atoms, alkyl groups having from 1 to 12 carbon atoms or cycloalkyl groups having from 3 to 12 carbon atoms, by dehydrogenation of pyrrolidines of the formula II: ##STR6## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined above, in the presence of a supported noble metal catalyst, wherein the dehydrogenation is carried out at from 150 to 300.degree. C. and pressures of from 0.01 to 50 bar and the noble metal catalyst comprises from 30 to 100% by weight of:a) palladium on an oxide of a rare earth or an oxide of an element of the 4.sup.th group (transition group IV) of the Periodic Table, orb) a platinum/palladium mixture on aluminum oxide, an oxide of a rare earth or an oxide of an element of the 4.sup.th group and from 0 to 70% by weight of alkali metal oxide or alkaline earth metal oxide.