Reactions of pyrrolidine with 2 equiv of aldehydes without any catalyst in a pressurized vessel at 140–200 °C yielded 1,3-disubstituted pyrroles. α-Branched aldehydes gave fairly good yields of the corresponding products by this method, which provides a facile non-oxidative procedure for synthesizing 1,3-dialkylpyrroles from inexpensive pyrrolidine and aldehydes.
1,3-Disubstituted pyrroles were prepared by a microwave-assisted reaction of pyrrolidine and aldehydes in toluene as well as in solvent-free conditions. Reactions were completed in a few minutes in the solvent-free condition but a long time (up to 30min) was necessary to complete reactions in toluene. Yields of products depended considerably on the aldehyde used.