Sulfamic acid as a green, reusable catalyst for stepwise, tandem & one-pot solvent-free synthesis of pyrazole derivatives
作者:Veera Swamy Konkala、Pramod Kumar Dubey
DOI:10.1016/j.cclet.2017.02.005
日期:2017.7
Abstract Sulfamic acid (SA) is a bi-functional, cost-effective and reusable green catalyst for the synthesis of 4-(pyrazol-4-yl)methylenepyrazol-5(4 H )-one derivatives by one-pot, three-component condensation of pyrazol-4-carbaxaldehydes, β -ketoesters and phenyl hydrazine (Route-I). In addition to this method, another simple condensation of pyrazol-4-carbaxaldehydes with pyrazolone in the presence
摘要氨基磺酸(SA)是一种双功能,经济高效且可重复使用的绿色催化剂,用于通过一锅,三组分合成4-(吡唑-4-基)亚甲基吡唑-5(4 H)-一衍生物。吡唑-4-氨基甲醛,β-酮酸酯和苯基肼的缩合反应(路线Ⅰ)。除此方法外,还报道了在无溶剂条件下,在SA的存在下,吡唑-4-氨基甲醛与吡唑酮的另一种简单缩合反应,收率很高。这些方案的优点是条件温和,无水后处理,收率高,催化剂容易获得,无需色谱分离和廉价的固体酸催化剂。此外,SA可以循环使用五次而不会失去其催化活性。