Highly efficient solvent-free synthesis of pyranopyrazoles by a Brønsted-acidic ionic liquid as a green and reusable catalyst

Journal of Chemical Sciences

Esan Bahramzade²  Javad Ebrahimi1³  Amir Habibi¹  Ali Mohammadi2⁴  Vahid Pakjoo¹ 

[1] Department of Chemistry, Islamic Azad University, Mashhad Branch, P.O. Box 9187147578, Mashhad, Iran$$;Department of Chemistry, Islamic Azad University, Mashhad Branch, P.O. Box 9187147578, Mashhad, Iranv$$;Young Researchers Club, Islamic Azad University, Mashhad Branch, P.O. Box 9187147578, Mashhad, Iran$$;Department of Chemistry, Faculty of Sciences, Ferdowsi University of Mashhad, P.O. Box 91775, Mashhad, Iran$$

关键词: Pyranopyrazoles;    solvent-free synthesis;    multicomponent reaction;    ionic liquid;    heterogeneous catalysts.;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

A simple, green and efficient protocol for synthesis of dihydropyrano[2,3-c]pyrazole derivatives is developed by a four component reaction of various benzaldehydes, ethyl acetoacetate, hydrazine hydrate and malononitrile in the presence of 3-methyl-1-(4-sulphonic acid)butylimidazolium hydrogen sulphate [(CH2)4SO3HMIM][HSO4], an acidic ionic liquid and as a catalyst, under solvent-free conditions. The key advantages of this process are high yields, shorter reaction times, easy work-up, purification of products by non-chromatographic method and the reusability of the catalyst.

【 授权许可】

Unknown