CHEMICAL REACTIVITY OF 1H-BENZIMIDAZOL-2-YL-ACETONITRILE AND DIMEDONE TOWARD SIMPLE CONDENSATES DERIVED FROM 3-FORMYLCHROMONE

The chemical reactivity of 1H-benzimidazol-2-ylacetonitrile and dimedone was investigated towards some simple condensates (1a-d and 2a-c) obtained from condensation reaction of 3-formylchromone with some active methylene compounds. Mainly, the used nucleophiles undergo nucleophilic addition at the olefinic carbon with concomitant cycloaddition or cyclocondensation. Chromonylacrylonitrile 1a reacted with 1H-benzimidazol-2-ylacetonitrile through gamma-pyrone ring opening followed by cyclocondensation giving pyrido[1,2-a]benzimidazole derivative 5. The simple condensates 2b and 2c showed similar behavior towards 1H-benzimidazol-2-ylacetonitrile and dimedone leading to the same products which are identical with those obtained from 3-formylchromone with the same reagents. Structures of the new synthesized products were established based on elemental analysis and spectral data.

Automated summary

The chemical reactivity of 1H-benzimidazol-2-ylacetonitrile and dimedone towards some simple condensates was investigated. The results showed that the nucleophilic addition reaction mainly occurred at the olefinic carbon with concomitant cycloaddition or cyclocondensation.