Azines and Imines of 4- and 5-t-Bu-Pyrrole-2-aldehyde. A Useful Synthesis of the Aldehydes

Abstract
The preparation of 4- and 5-t-Bu-pyrrole-2-aldehyde can be brought about in a high yield and purity using Vilsmeier-Haack type reactions as conclusions to reaction sequences involving a 1-benzenesulfonyl directing group on pyrrole (4-substitution) or the formamidinium salt of pyrrole (5-substitution). Azines/imines were prepared and characterised.