An efficient catalyst- and solvent-free method for the synthesis of medicinally important dihydropyrano[2,3-c]pyrazole derivatives using ball milling technique
作者:Mohammad G. Dekamin、Mohammad Alikhani、Atefeh Emami、Hossein Ghafuri、Shahrzad Javanshir
DOI:10.1007/s13738-015-0793-7
日期:2016.3
Dihydropyrano[2,3-c]pyrazole annulated heterocyclic compounds with diverse substituents on the 4H-pyran ring were efficiently prepared via a one-pot and four-component reaction of ethyl acetoacetate, hydrazine hydrate, aromatic aldehyde, and malononitrile. The procedure proceeds without utilization of any catalyst or solvent using ball milling technique at ambient temperature to afford desired medicinally important dihydropyrano[2,3-c]pyrazole derivatives. This protocol offers several advantages such as avoiding the use of any toxic and hazardous catalyst or solvent, mild reaction conditions, high to quantitative yields of products, low cost, and straightforward work-up.
通过乙酰乙酸乙酯、水合肼、芳香醛和丙二腈的一锅四组份反应,高效地制备了 4H 吡喃环上具有不同取代基的二氢吡喃并[2,3-c]吡唑环状杂环化合物。该过程无需使用任何催化剂或溶剂,采用球磨技术在常温下进行,即可制备出所需的具有重要药用价值的二氢吡喃并[2,3-c]吡唑衍生物。该方法具有多个优点,如避免使用任何有毒有害的催化剂或溶剂、反应条件温和、产品收率高且定量、成本低以及操作简单。