Regiospecific generation and application of 3-lithiomethyl-2-methyl-1-phenylpyrazolin-5-one as 1,3-binucleophile in aromatic annelation: A novel approach for synthesis of 1,2-disubstituted indazolones and their condensed analogs
作者:Kethiri R. Reddy、Amrita Roy、Hiriyakkanavar Ila、Hiriyakkanavar Junjappa
DOI:10.1016/0040-4020(95)00650-w
日期:1995.10
The enolate anion 5A generated by deprotonation of 2,3-dimelhyl- 1-phenylpyrazolin-5-one is shown to undergo highly regioselective γ-1,4-addition to α-oxoketene dithioacelals followed by cycloaromatizalion in the presence of boron trifluoride etherate to afford wide range of novel substituted and condensed indazolones in good yields.
由2,3-二甲基-1-1-苯基吡唑啉-5-酮去质子化生成的烯醇酸根阴离子5A被证明对α-氧杂环丁烯二硫代芳烃具有高度区域选择性的γ-1,4-加成反应,然后在三氟化硼醚化物存在下环芳基化。以良好的收率提供了多种新型的取代和缩合的吲唑酮。