A novel route to 4-oxy/thio substituted-1H-pyrazol-5(4H)-ones via efficient cross-Claisen condensation
作者:R. Venkat Ragavan、V. Vijayakumar
DOI:10.1002/jhet.558
日期:2011.3
α‐Oxy/thio substituted β‐keto esters were synthesized through an efficient cross‐Claisen condensation of oxy/thio substituted acetic acid ethyl esters with acid chlorides, which in turn converted in situ into 4‐oxy/thio substituted‐1H‐pyrazol‐5(4H)‐ones by the addition of hydrazine and its derivatives. This method has been found to be extremely fast, general, and useful toward the synthesis of inaccessible
通过氧/硫代取代的乙酸乙酯与酰基氯的有效交叉克莱森缩合反应合成α-氧/硫代取代的β-酮酯,然后原位转化为4-氧/硫代取代的1 H-吡唑‐5(4 H)‐加肼及其衍生物。已发现该方法非常快速,通用,可用于合成难以接近的吡唑啉酮和合成需要4-氧/硫取代的吡唑啉酮。J.杂环化学。(2011)。