Synthesis of some new benzimidazole-5(6)-carboxylic acids

GOKER H., OLGEN S., ERTAN R., AKGUN H., Ozbey S., KENDI E., ...More

JOURNAL OF HETEROCYCLIC CHEMISTRY, vol.32, no.6, pp.1767-1773, 1995 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 32 Issue: 6
  • Publication Date: 1995
  • Doi Number: 10.1002/jhet.5570320617
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.1767-1773
  • Hacettepe University Affiliated: Yes


The title compounds, 1,2-dialkyl-benzimidazole-5(6)-carboxylic acids 34-45 were prepared at four steps; 1) preparation of mono amide derivatives 1-11 by the reaction of methyl 3,4-diaminobenzoate and substituted phenyl or phenoxyacetic acid chlorides; 2) preparation of the methyl benzimidazolecarboxylates 12-22, with zinc chloride and dry hydrogen chloride gas; 3) alkaline hydrolysis of the esters 23-33; and 4) substitution of the imidazole ring with benzyl or p-fluorobenzyl bromide, in alkali medium. 2-Aryl-benzimidazole-5(6)-carboxylic acids 50-53 were prepared via the oxidative condensation of 3,4-diaminobenzoic acid and aromatic aldehydes with cupric ion.