Abstract
Pyrrole is one of the most important one-ring heterocycles because of its widespread presence in natural products and unnatural bioactive compounds and drugs in clinical use. The preparation of pyrroles by reaction between primary amines, β-dicarbonyl compounds, and α-halo ketones, known as the Hantzsch pyrrole synthesis, is reviewed here for the first time. In spite of its age and its named reaction status, this method has received little attention in the literature. Recent work involving the use of non-conventional conditions has rejuvenated this classical reaction and this is emphasized in this review. Some applications of the Hantzsch reaction in target-oriented synthesis are also discussed.
1 Introduction
2 The Conventional Hantzsch Pyrrole Synthesis
3 Hantzsch Pyrrole Synthesis under Non-conventional Conditions
4 Applications of the Hantzsch Pyrrole Synthesis
5 Conclusions
Key words
pyrrole - green chemistry - solid-phase synthesis - sonochemistry - flow synthesis - photoredox catalysis - mechanochemical synthesis
