2,3-Dihydrospiro[1H-4- and 5-azabenzimidazole-2,1? -cyclohexane] ( = Spiro[cyclohexane-1,2?(3?H)-1?H-imidazo[4,5-b]pyridine] and Spiro[cyclohexane-1,2?(3?H)-1?H-imidazo[4, 5-c]pyridine]): Reactions with Nucleophiles
作者:Stefan Schwoch、Walter Kramer、Richard Neidlein、Hans Suschitzky
DOI:10.1002/hlca.19940770811
日期:1994.12.14
6-Michael addition (Schemes 2 and 4). The bromo-dihydro-1H-azabenzimidazole 4b lost the Br-atom when treated with piperidine or morpholine yielding the corresponding disubstituted 2H-azabenzimidazole 21 (Scheme 3). Reductive ring opening of the substituted spiro compounds leads to mono- and disubstituted diaminopyridines which are intermediates for fused pyridine ring systems with substituents often
容易得到的目标化合物4A和24与N-,O-,以MnO的存在S-,和C-亲核试剂2,得到相应的单-或二取代的2个ħ -azabenzimidazoles(= azaisobenzimidazoles),例如,11-18和26a–h,或分别通过添加1、4-或1,6-迈克尔(2,3-dihydro-1 H - azabenzimidazoles(= dihydro-azabenzimidazoles),例如9和10和27和28(方案2和4)。溴二氢-1 H当用哌啶或吗啉处理时,-氮杂苯并咪唑4b失去Br原子,得到相应的二取代的2 H-氮杂苯并咪唑21(方案3)。取代的螺环化合物引线的还原性开环单和二取代的二氨基吡啶,其是用于与通常都不是由常规途径可用的潜在药物的兴趣和取代基稠合的吡啶环系统的中间体(见32 - 37)。例如,从4a开始,三步合成镇痛性氟吡汀马来酸酯(= 2-氨基-6-[((4-