2H-benzimidazoles. Part 5. Convenient synthons for tricyclic heterocycles
作者:Armin Cada、Walter Kramer、Richard Neidlein、Hans Suschitzky
DOI:10.1002/hlca.19900730417
日期:1990.6.20
The readily available 5-nitrospiro[2H-benzimidazole-2,1′-cyclohexane] (1) was converted into the carbonitrile 5 and the 4-phenylthio derivative 4. The NO2 or the PhS substituents in 4 could be replaced regiospecifically by reaction with Me3SiN3 or NaN3, respectively. The 5-azido derivative 8, resulting from NO2-group replacement was made to cyclize photolytically to give the angular spiro[cyclohex
容易获得的5-硝基螺[2 H-苯并咪唑-2,1'-环己烷](1)被转化为腈5和4-苯硫基衍生物4。的NO 2或取代基PHS在4可以通过区域专一性与我反应来代替3的SiN 3或NaN 3分别。使由NO 2基团取代产生的5-叠氮基衍生物8进行光解环化,得到角螺[环己烷-咪唑并吩噻嗪] 18。从4中的PhS置换中获得的叠氮化物9自发环化得到角螺[环己烷-咪唑并苯并恶二唑] 10,经还原水解,得到苯并呋喃-4,5-二胺14。通过常规方法将二胺14转化为咪唑并苯并恶二唑15,恶二唑并喹喔啉16和硒二唑并恶唑17。通过简单的步骤,将腈5分别转化为“伸出的”角蝶啶和嘌呤类似物25和28。