Ultrasound Promoted and Ionic Liquid Catalyzed Cyclocondensation Reaction for the Synthesis of 4(3H)‐Quinazolinones

Abstract

4(3H)-Quinazolinones were synthesized in high yields by one-pot three-component condensation of anthranilic acid, carboxylic acid and aniline in the presence of ionic liquid such as 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMImBF 4 ) as catalyst under solvent free and neutral conditions.

Multicomponent reactions in unconventional solvents: state of the art

“…233 In the presence of [BMIm]BF 4 , one-pot three-component condensation of anthranilic acid, carboxylic acid and aniline proceeded well with the aid of ultrasound irradiation, providing 4(3H)-quinazolinones in high yields. 234 Ionic liquid [BMIm]PF 6 has been demonstrated by Xu et al 235 to be an efficient and recyclable medium for highly chemoselective synthesis of 2,2-dimethyl-6-substituted 4-piperidones 123 via a L-proline catalyzed four-component tandem Mannich reaction of ammonia, aldehydes and acetone (Scheme 69). The ionic liquid [BMIm]PF 6 not only serves as a reaction medium, but also significantly enhances the chemoselectivity.…”

Thiamine hydrochloride: An efficient catalyst for one-pot synthesis of quinoxaline derivatives at ambient temperature

“…As a part of our ongoing program on the development of novel synthetic methods in organic synthesis under mild conditions, 36 we wish to report a simple and efficient method for the synthesis of quinoxalines in the presence of thiamine hydrochloride (VB 1 ) as an inexpensive, non-toxic and metal ion free catalyst at ambient temperature (scheme 1).…”

Update 1 of: Ionic Liquids in Heterocyclic Synthesis

“…When this reaction was performed in the molecular solvent EtOH, the addition of NaOH and 30% H 2 O 2 under reflux for 1 h was necessary to obtain 75% yield of the product. 432 Pawar et al 433 reported the synthesis of 4(3H)-quinazolinones 312 promoted by [BMIM][BF 4 ] under ultrasound irradiation. The products 312 were achieved from the three-component condensation of anthranilic acid 91, primary aromatic amines 5, and carboxylic acid 56, with equimolar amounts of the reactants and IL (Scheme 97).…”

“…Pawar et al reported the synthesis of 4­(3 H )-quinazolinones 312 promoted by [BMIM]­[BF 4 ] under ultrasound irradiation. The products 312 were achieved from the three-component condensation of anthranilic acid 91 , primary aromatic amines 5 , and carboxylic acid 56 , with equimolar amounts of the reactants and IL (Scheme ).…”