A re-engineering approach: synthesis of pyrazolo[1,2-a]pyrazoles and pyrano[2,3-c]pyrazoles via an isocyanide-based four-component reaction under solvent-free conditions

作者：Shaabani Ahmad^*; Sepahvand Heshmatollah; Nejad Mina Keramati

来源：Tetrahedron Letters, 2016, 57(13): 1435-1437.

DOI：10.1016/j.tetlet.2016.02.051

• Re-engineering approach
• Pyrazolo[1,2-a]pyrazoles
• Pyrano[2,3-c]pyrazoles
• Four-component reaction
• Solvent-free

A new protocol based on a re-engineering approach has been developed for the efficient synthesis of pyrazolo[1,2-a]pyrazoles and pyrano[2,3-c]pyrazoles via an isocyanide-based four-component reaction of dialkyl acetylenedicarboxylates, isocyanides, and ethyl acetoacetate with hydrazine hydrate or phenyl hydrazine. The reactions were carried out under solvent- and catalyst-free conditions at mild temperatures and short times in good yields.

• 出版日期2016-3-30