A synthetic methodology for a protecting-group-free formation of 3-aryl-substituted 4-aminopyrazoles from acetophenones via a telescoped oximation and hydrazine condensation of 1,3-ketoaldehydes to generate nitrosopyrazoles, and copper-catalyzed NaBH4 reduction of the nitroso group, was demonstrated. The synthesis tolerates a broad scope of substrates with a variety of substituents on the phenyl ring
一种通过 1,3-酮醛缩合
肟化和
肼缩合生成亚硝基
吡唑,以及
铜催化的亚硝基 NaBH 4还原,从
苯乙酮无保护基团形成 3-芳基取代的
4-氨基吡唑的合成方法, 被证明了。该合成耐受范围广泛的苯环上具有多种取代基的底物,以提供所需的产物。