Synthesis of 6-amino-4-aryl-3-methyl-1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles by heterogeneous reusable catalysts
作者:Hamid Reza Shaterian、Mehrnoosh Kangani
DOI:10.1007/s11164-013-1097-0
日期:2014.5
A new, efficient and environmentally benign protocol for the one-pot, four-component synthesis of 1,4-dihydropyrano[2,3-c]pyrazoles by reaction of hydrazine monohydrate, ethyl acetoacetate, arylaldehydes and malononitrile in the presence of a green catalytic amount of P2O5/SiO2, H3PO4/Al2O3, cellulose sulfuric acid and starch sulfuric acid is described. The use of non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are the advantages of this method.
描述了一种新的、高效且环保的合成方案,通过在绿色催化剂P2O5/SiO2、H3PO4/Al2O3、纤维素硫酸和淀粉硫酸的存在下,使用一水合肼、乙酰乙酸乙酯、芳醛和丙二腈进行一锅法四组分合成1,4-二氢吡喃[2,3-c]吡唑。这种方法的优点包括使用无毒且廉价的材料、简单且清洁的后处理、短反应时间和良好的产品产率。