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 substitutedβ‐ketoesters 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