Brønsted Acidic Ionic Liquids: New, Efficient, and Green Promoter System for the Synthesis of 4(3H)-Quinazolinones

Abstract

A simple, inexpensive, and efficient new synthesis of 4(3H)-quinazolinones from the reaction of 2-aminobenzamide with aroyl chlorides in the presence of two new halogen-free Brønsted acidic ionic liquids, 3-methyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate [(CH₂)₄SO₃HMIM][HSO₄] and 1-(4-sulfonic acid) butylpyridinium hydrogen sulfate [(CH₂)₄SO₃HPY][HSO₄], green and reusable catalysts, with excellent product yields under solvent-free conditions is reported. The products could be separated simply from the catalyst, and the catalyst could be recycled without noticeably decreasing the catalytic activity.

Keywords:

• 2-Aminobenzamide
• aroyl chlorides
• Brønsted acidic ionic liquids
• 4(3H)-quinazolinones

Notes

^a Isolated yields.

^a All the products were known and characterized by ¹H NMR and IR spectral data and by comparison with authentic samples.^{[ 12 ]}

^b Isolated yields.