[BPy]HSO₄ Acidic Ionic Liquid as a Novel, Efficient, and Environmentally Benign Catalyst for Synthesis of 1,5‐Benzodiazepines under Mild Conditions

Abstract

A novel and simple ionic liquid methodology for the synthesis of 1,5‐benzodiazepines is described. 1‐Butylpyridinium hydrogen sulphate ([BPy]HSO₄), an acidic room‐temperature ionic liquid, as a novel and efficient catalyst, was synthesized and used in the preparation of a series of 1,5‐benzodiazepine derivatives by the reaction of o‐phenylenediamine with chalcones under mild conditions. This method is easy, efficient, environmentally friendly, economical, free of toxic catalysts, and has good yields for the formation of 1,5‐benzodiazepines

Keywords:

• Acidic counterion
• 1,5‐benzodiazepines
• 1‐butylpyridinium hydrogen sulpates
• room‐temperature ionic liquid