Biaryl sulfonamides from O-acetyl amidoximes: 1,2,4-Oxadiazole cyclization under acidic conditions
作者:Stefan Dosa、Jörg Daniels、Michael Gütschow
DOI:10.1002/jhet.603
日期:2011.3
A series of 4‐cyanobenzenesulfonamides (1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h) was converted to the corresponding O‐acetylated amidoximes (2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h). The reaction of 1a was exemplarily investigated with respect to the formation of a byproduct, which was identified as 1,2,4‐oxadiazole derivative 3a. This observation led to the development of an improved procedure for the preparation of
将一系列的4-氰基苯磺酰胺(1a,1b,1c,1d,1e,1f,1g,1h)转化为相应的O-乙酰化ated胺肟(2a,2b,2c,2d,2e,2f,2g,2h)。对1a的反应进行了示例性的副产物形成研究,确定为1,2,4-恶二唑衍生物3a。该观察结果导致开发了用于制备2a,2b,2c,2d,2e,2f,2g,2h的改进程序。在乙酸中加热后,化合物2可以高产率和高纯度地转化为1,2,4-恶二唑3a,3b,3c,3d,3e,3f,3g,3h。J.杂环化学。(2011)。