Kinetics and mechanisms of nucleophilic displacements with heterocycles as leaving groups. Part 14. The preparation and reactions of some further α-heteroaryl-pyridinium salts
作者:Alan R. Katritzky、Jacek Z. Brzezinski、Yu Xiang Ou、Giuseppe Musumarra
DOI:10.1039/p29830001463
日期:——
dihydrocarbazole and dihydrobenzothiophene rings and α-benzothiazole substituents are described, together with their conversion to a variety of derived pyridiniums. The N-(2-pyridyl) group rearranges thermally at 60°C from the pyridinium nitrogen to the nitrogen atom of a 2-(2-benzimidazolyl) group [in (19)]; similar rearrangement in the carbazole (7) is complicated by dehydrogenation. Compared with
描述了含有稠合的二氢咔唑和二氢苯并噻吩环和α-苯并噻唑取代基的新型吡啶鎓,以及它们转化为各种衍生的吡啶鎓。所述ñ - (2-吡啶基)基团重排热在与吡啶鎓氮到2-(2-苯并咪唑基)基团的氮原子60°C [(19)]; 咔唑(7)中类似的重排因脱氢而变得复杂。与相应的2,4,6-三苯基吡啶鎓相比,用α-2-苯并噻唑基取代α-苯基对N-苄基具有大的增速作用,但对N -n-烷基则小得多。通过稠合的二氢苯并噻吩系统取代α-苯基显示出N-苄基的速率提高; 发生环裂变N-正烷基。在单项研究中,咔唑与二苯并噻吩一样有效,但苯并咪唑的效果不如苯并噻唑。