Trifluoroacetic acid: An efficient catalyst for paal-knorr pyrrole synthesis and its deprotection

Abstract

In the present work, we demonstrated a simple and an efficient method for the condensation of substituted aryl/heteroaryl amines with acetonylacetone in the presence of trifluoro acetic acid to afford the corresponding 2,5-dimethyl-1-substitued pyrroles using Paal-Knorr synthesis in excellent yields. Trifluoroacetic acid was used under reflux condition for the deprotection of 2,5-dimethyl-1-substitued pyrroles to their corresponding substituted aryl/heteroaryl amines in moderate yields. 2,5-Dimethyl-1-substitued pyrrole were characterized by NMR and LC-MS. The yield of the compounds was found to be excellent.