Studies on Seven-membered Ring Compounds. XVI. Synthesis of 2-Substituted Cycloheptimidazole Derivatives
作者:Hideo Nakao、Genshun Sunagawa
DOI:10.1248/cpb.13.465
日期:——
In order to obtain 2-substituted cycloheptimidazole, the reaction of 2-methoxytropone (I) with substituted guanidine and amidine was carried out. Reaction of I with monoalkylguanidine afforded a small amount of 2-alkylaminocycloheptimidazole besides 1-alkyl-2-imino-1, 2-dihydrocycloheptimidazole. Reaction of 2-bromo-7-methoxytropone with monoalkylguanidine afforded 2-alkylamino-4-bromocycloheptimidazole and rearranged product, 2-amino-3-alkyl-4(3H)-quinazolinone. However, reaction of dialkylguanidine with I and 2-bromo-7-methoxytropone afforded only one product, 2-dimethylamino-and 2-dimethylamino-4-bromocycloheptimidazole, respectively. Reaction of aromatic amidine with I or 2-chlorotropone afforded 2-phenyl-and 2-pyridylcycloheptimidazole derivatives. Among cycloheptimidazole derivatives, 2-dimethylaminocycloheptimidazole has been found to undergo easily electrophilic substitution reaction, bromination and nitration.
为了获得2-取代的环庚咪唑,进行了2-甲氧基特罗庚酮(I)与取代胍和胸腺素的反应。I与单烷基胍的反应除产生少量的2-烷基氨基环庚咪唑外,还生成了1-烷基-2-亚胺-1,2-二氢环庚咪唑。将2-溴-7-甲氧基特罗庚酮与单烷基胍反应得到了2-烷基氨基-4-溴环庚咪唑及重排产物2-氨基-3-烷基-4(3H)-喹唑啉酮。然而,双烷基胍与I及2-溴-7-甲氧基特罗庚酮的反应仅生成一种产物,分别为2-二甲氨基和2-二甲氨基-4-溴环庚咪唑。芳香胺素与I或2-氯特罗庚酮的反应生成了2-苯基和2-吡啶基环庚咪唑衍生物。在环庚咪唑衍生物中,2-二甲氨基环庚咪唑被发现容易发生电亲替代反应、溴化和硝化。