Utility of Nitrogen Nucleophiles: a Simple Route for the Synthesis of 2-Substituted Benzimidazolylpyrimidines

GRAPHICAL ABSTRACT

Abstract

An efficient and simple route for the synthesis of 2-substituted benzimidazolylpyrimidines 5a-i has been developed from benzimidazolylunsaturated nitriles 2 using nitrogen nucleophiles. Treatment of 2 with thiourea/urea/guanidine hydrochloride in aq. KOH under reflux for 30 min gave 3, which on further alkylation with an alkylating agent under PTC conditions gave 5a-i. Alternatively 5a-i could also be prepared by treatment of 2 with an alkylating agent under PTC conditions followed by treatment with thiourea /urea/guanidine hydrochloride in aq. KOH for 30 min.

Keywords:

• Benzimidazolylpyrimidines
• 2-mercaptobenzimidazole
• benzaldehyde
• nitrogen nucleophiles
• phase transfer catalyst