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Updated: May 12, 2026

Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
One pot three component reaction for the rapid synthesis of pyrrolo[1,2-a]benzimidazoles
Wei-Shun Hsu1, Vijaykumar Paike, Chung-Ming Sun
1Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan, ROC.
Abstract:
An efficient strategy for the synthesis of pyrrolo[1,2-a]-benzimidazole (PBI) linked to an ionic liquid (ILs) as a soluble support under microwave irradiation was explored. The key intermediate benzimidazoles were synthesized via N-acylation followed by cyclodehydration of IL-supported methyl-3-amino-4-(isobutylamino) benzoate. The synthesis of the IL-bound PBI was performed by one-pot three-component condensation under microwave dielectric heating, which involved a Knoevenagel condensation and a [4+1]-cycloaddition reaction. The reaction was monitored directly by means of (1)H NMR. All final products were obtained in good yield and high purity after precipitation.
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