Polyfunctional pyrazoles 5*. preparative synthesis of 1-aryl-4-formylpyrazole- 3-carboxylic acids
摘要:
Treatment of methyl pyruvate N-arylhydrazones with the Vilsmeier-Haack reagent gave methyl 1-aryl4- formylpyrazole-3-carboxylates, basic hydrolysis of which yielded the corresponding acids.
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