Imidazoles pyrrolo- -benz

Dimethyl-2-(2-methoxy-4-methylthio-phenyl)-6-oxo-1,5,6,7-te trahydro-(pyrrolo[2,3-J]benz-imidazol> 81% Schmp. 293-295°... 

Amino-2,3-dihydro-7-methyl-lH-pyrrolo[l,2-a]benz-imidazole (2.9 mmol) was added to ALTUS 20 CLEC (310 mg) in 104 ml EtOAc, then stirred 30 minutes, and filtered. The solution was washed three times with 10 ml CHC13, then concentrated. The residue was purified by chromatography using silica gel with 3% methyl alcohol in CHC13, then recrystallized from EtOAc/hexane, and the product isolated in 37% yield, mp = 219-220°C. 

Preparation of R-(—)-3-phenoxyamido-6-azindinyl-2,3-dihydro-7-methyl-lH-pyrrolo[l,2-a]benz-imidazole 5,8-dione... 

A reductive cyclization of o-alkenylaminoanilines (37.7) in the presence of rhodium acetate in an atmosphere of carbon monoxide and hydrogen under pressure gives the diazocine and a smaller amount of the pyrrolo l,2-a]benz-imidazole... 

IL-supported one-pot multicomponent reaction for the construction of bi-heterocyclic-fused pyrrolo[l,2-a]benz-imidazoles 114 under microwave irradiation were reported by Sxm and coworkers (Scheme 12) [47]. The IL-anchored diamines 97 were coupled with cyanoacetic acid followed by cyclodehydration to generate key intermediate 2-sub-stituted benzimidazoles 113. IL-supported 113 reacted with aldehyde and isocyanide through Knoevenagel condensation followed by [4 +1] cycloaddition in one-pot affording pyrrolo[l,2-fl]benzimidazole 114. Remarkably, this is the first time applied IL support and isocyanide-based multicomponent react for the synthesis of fused tricyclic heterocycles under microwave irradiation. 

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