Electrophilic aromatic substitution of 3-alkoxy-6-alkyl-2-cyano-4,5,6a,11-tetraazabenzo[<i>a</i>]fluorene with orthoesters
作者:Yoshihisa Okamoto、Yoshimi Yamaguchi、Mitsuaki Maeda、Yoshihisa Kurasawa
DOI:10.1002/jhet.5570450313
日期:2008.5
Fused tetracycles, 6-alkyl-3-alkoxy-2-cyano-4,5,6a,11-tetraazabenzo[a]fluorene derivatives (5a,b,c,d,e,f), are synthesized from 2-alkoxy-5-(benzimidazol-2-ylidene)-3-cyano-6-imino-5,6-dihydro-pyridines (4b,c), and when refluxed in ethyl orthoacetate or ethyl orthopropionate, the elecrophilic aromatic substitution occurs at the ortho position of the cyanopyridine ring in the fused tetracycles (5b,c
熔融四环,由2-烷氧基-合成6-烷基-3-烷氧基-2-氰基-4,5,6a,11-四氮杂苯并[ a ]芴衍生物(5a,b,c,d,e,f)。 5-(苯并咪唑-2-亚烷基)-3-氰基-6-亚氨基-5,6-二氢吡啶(4b,c),当在原乙酸乙酯或原丙酸乙酯中回流时,亲电子芳族取代发生在邻位稠合四环中的氰基吡啶环(5b,c,e,f)得到6-烷基-3-烷氧基-2-氰基-1-乙基-4,5,6a,11-四氮杂苯并[a ]芴(6b,c,e,f)。