title: One pot three component reaction for the rapid synthesis of pyrrolo[1,2-a]benzimidazoles.
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.
authors.affiliation: Department of Applied Chemistry, National Chiao Tung University, Hsinchu 300, Taiwan, ROC.
authors.forename: Wei-Shun
authors.initials: WS
authors.lastname: Hsu
authors.forename: Vijaykumar
authors.initials: V
authors.lastname: Paike
authors.forename: Chung-Ming
authors.initials: CM
authors.lastname: Sun
mesh_terms: D000215:Acylation; D001562:Benzimidazoles / Q000138:chemical synthesis*; D001565:Benzoates / Q000737:chemistry*; D061565:Cycloaddition Reaction; D052578:Ionic Liquids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008872:Microwaves; D015394:Molecular Structure; D011758:Pyrroles / Q000138:chemical synthesis*; D013237:Stereoisomerism
chemical_list: D001562:Benzimidazoles; D001565:Benzoates; D052578:Ionic Liquids; D011758:Pyrroles