Competitive cyclisations of singlet and triplet nitrenes. Part 8. The 1-(2-nitrenophenyl)pyrazoles and related systems
作者:John M. Lindley、Ian M. McRobbie、Otto Meth-Cohn、Hans Suschitzky
DOI:10.1039/p19800000982
日期:——
The title nitrenes, derived by nitro-group deoxygenation with triethyl phosphite or by thermolysis or photolysis of the corresponding azide, have been studied. The effect of substituents (Cl, Br, OMe, NMe2, Me, CF3, and NO2) both meta and para to the nitrene has been examined as a determinant of the preferred mode of cyclisation to either a pyrazolobenzotriazole or a pyrazoloquinoxaline. Similarly
已经研究了通过亚磷酸三乙酯的硝基基团脱氧或通过相应叠氮化物的热解或光解而得到的标题腈。取代基(氯,溴,青梅,NME的效果2中,Me,CF 3,和NO 2)两者间位和对位已经研究了对硝基苯的吡咯烷酮是确定为吡唑并苯并三唑或吡唑并喹喔啉的优选环化方式的决定因素。同样,已经研究了溶剂,敏化剂和淬灭剂的作用。已经定义了异构体1-和2-(2-硝基苯基)-4,5,6,7-四氢吲唑的途径,并通过研究这些产物的腈介导的环化作用对文献进行了修正。还研究了类似的1-(2-carbenophenyl)-和1-(2-nitrenosulphonylphenyl)-3,5-二甲基吡唑的化学反应,前者给出了2-(3,5-二甲基吡唑-1-基)-苯并恶嗪和-苄醇,后者则产生分子内的氮攻击(吡唑并苯并噻嗪三嗪)和分子间反应的产物。所有反应途径的合理化已经提出。