Reactions of 2,3-dihydrospiro[1<i>H</i>-4- and 5-azabenzimidazole-2,1′-cyclohexane] with nucleophiles: A potential route to some substituted aromatic heterocycles
作者:Ralf Reizner、Walter Kramer、Richard Neidlein、Hans Suschitzky
DOI:10.1002/jhet.5570360118
日期:1999.1
results in loss of the Br-atom presumably by an AEa-mechanism. Reduction of the substituted azaisobenzimidazoles with sodium hydrosulfite followed by fission of the cyclohexane ring leads to substituted o-diaminopyridines. They were cyclised in situ with various condens ing agents to give new heterocyclic systems. Equimolar mixtures of some azaisobenzimidazoles and dihydroazabenzimidazoles lead to the
容易得到目标化合物2,16及27与pseudohalogenes(氰化物,叠氮化物),碳和杂环反应Ñ -nucleophiles在二氧化锰的存在下,得到相应的取代的azaisobenzimidazoles(= 2 ħ -azabenzimidazoles)4,8,23- 26和29-33,36或dihydroazabenzimidazoles(= 2,3-二氢-1- ħ -azabenzimidazoles 7,22,34和35,在8两种咪唑基取代基之一可以被亲核试剂取代,生成9-15的化合物。的治疗6'-溴-2,3-二氢-4-氮杂苯并咪唑16与在BR-原子推测的损失吗啉或哌啶的结果由AE一个-mechanism。用亚硫酸氢钠还原取代的氮杂异苯并咪唑类,然后裂环环己烷导致取代的邻-二氨基吡啶。他们被原地环化与各种缩合剂,以提供新的杂环系统。一些氮杂异苯并咪唑和二氢氮杂苯并咪唑的等摩尔混合物