[H-Pyrr][HSO₄] as an Efficient Ionic Liquid Catalyst for the Synthesis of Xanthenes, Tetraketones, and Triazolo[2,1-b]quinazolinones

Abstract

Pyrrolidin-1-ium hydrogen sulfate ([H-Pyrr][HSO₄]) was prepared by a simple and atom-economic neutralization reaction of sulfuric acid and pyrrolidine. This reagent can be used as an easily available, cheap, recyclable, and environmentally benign catalyst for the promotion of the synthesis of 1,8-dioxo-octahydro-xanthenes, tetraketones, and triazolo[2,1-b]quinazolinone derivatives. Easy preparation of the catalyst, simple work-up procedure, green process, high yields, and short reaction times are the most important advantages of this method.

Keywords:

• 18-dioxo- octahydroxanthene
• [H-Pyrr][HSO₄]
• pyrrolidine
• tetraketone
• triazolo[21-b]quinazolinone

Acknowledgments

We are thankful to the Research Council of University of Guilan for the partial support of this research.