苯并[4,5]咪唑并[2,1-b]-和苯并[4,5]恶唑并[2,3-b]喹唑啉酮等苯并稠合喹唑啉酮因其在生物学上的潜在应用而引起人们极大的兴趣。活性物质。在此,我们报道了用 2-异硫氰基苯甲酸甲酯处理各种邻苯二胺得到硫代喹唑啉酮,其在 K 2 CO 3 存在下与三苯基二氯化铋原位反应,得到在温和条件下以良好至优异的产率获得所需的苯并咪唑并喹唑啉酮。三苯基二氯化铋作为一种有效的环化脱硫试剂,促进了硫代喹唑啉酮向四环产物的转化。该串联反应中的所有步骤均在室温下进行。本反应体系还可应用于以2-氨基苯酚为原料合成苯并恶唑并喹唑啉酮。
A convenient oxidative cyclodesulfurization method toward the synthesis of benzofused nitrogen heterocycles using inexpensive and readily available potassium periodate as an oxidant was developed. Upon treating isothiocyanates with ortho-substituted anilines bearing N,N-, N,O-, and N,S-bis-nucleophiles, followed by an intramolecular cyclization of the in situ generated monothioureas, substituted 2-aminobenzazole