Synthesis, characterization, and bioevaluation of 1,2-disubstituted benzimidazole derivatives for their antiplant virus activity

Reaction of o-chlorobenzoic acid with isoindolin-1,3-dione in the presence of conc. H₂SO₄ afforded 2-chloro-5 [(1,3-dioxoindolin-2-yl) methyl] benzoic acid (1) which on reaction with o-phenylenediamine in pyridine furnished 2-[3-(1H-benzo [d] imidazol-2-yl)-4-chlorobenzyl] isoindoline-1, 3-dione (2). When compound (2) was allowed to react with benzaldehyde and a primary aromatic amine 2-({4-chloro-3-[1-(4-aryl-amino) phenyl methyl]-1H-benzo [d] imidazol-2-yl} benzyl)-isoindoline 1,3-diones (3) were obtained in moderate yields. Compounds (3) were evaluated for their antiviral activity against Tobacco mosaic virus and Sunhemp rosette virus.