Synthesis and Tautomeric Structure of 3,6-bis(arylazo)pyrazolo [1,5-<i>a</i>]pyrimidine-5,7(4<i>H</i>,6<i>H</i>)-diones
作者:Ahmad S. Shawali、Mosselhi A. N. Mosselhi、Thoraya A. Farghaly、Mohamed R. Shehata、Nagla M. Tawfik
DOI:10.3184/030823408x339782
日期:2008.8
Two series of 3,6-bis(arylazo)pyrazolo[1,5-a]pyrimidine-5,7-diones were prepared, and their acid dissociation constant pKas were determined and correlated with the Hammett equation. The results of these correlations, together with the spectroscopic data, indicated that the title compounds exist predominantly in the 3-arylazo-6-arylhydrazonopyrazolo[1,5-a]pyrimidine-5,7-dione tautomeric form, both in
制备了两个系列的 3,6-双(芳基偶氮)吡唑并 [1,5-a] 嘧啶-5,7-二酮,测定了它们的酸解离常数 pKas,并与哈米特方程相关联。这些相关性的结果以及光谱数据表明,标题化合物主要以 3-芳基偶氮-6-芳基肼基吡唑并[1,5-a]嘧啶-5,7-二酮互变异构形式存在,无论是固体还是溶液相。