Study of the Mannich reaction: beta-amino-methylation of N-aryl and N-azaheteroaryl-substituted 2,5-dimethylpyrroles, compounds with potential biological activity

Owing to the increasing need of drugs for the treatment of a variety of fungal and bacterial opportunistic infections, a study has been started with the aim of synthesizing structures amenable to a number of easily-to-perform structural modifications in order to meet the requirement of bypassing resistance phenomena. This paper reports on the synthesis of several N-(alpha-azaheteroaryl)-substituted 2,5-dimethyl-pyrroles bearing in one beta-position (or in both beta-positions) aminomethyl groups, introduced via a Mannich reaction. Electronic and steric effects by the N-(azaheteroaryl) substituents and the 2- and 5-methyl groups on the course of the Mannich reaction are discussed along with the results of in vitro tests against many Candida species, some bacteria, and several pathogenic plant fungi.