Purported Synthesis of 3,4,7,8-Tetraphenyl-1,2,5,6-tetraazocine from Benzil and Hydrazine: Competing Cyclization and Carbon–Carbon σ-Bond Scission
作者:John J. Eisch、Tsz Y. Chan、John N. Gitua
DOI:10.1002/ejoc.200700848
日期:2008.1
derivative was detected. The following products were unambiguously formed from the heating of molten benzil monohydrazone (%): benzil (10), benzaldehyde (10), benzamide (22), benzyl phenyl ketone (19), benzil bis(ketazine) (11), 3,4,5,6-tetraphenylpyridazine (9), benzil benzaldehyde azine (10), and, after column chromatography, 2,4,5-triphenylimidazole (2). This last component had a melting point and the
3,4,7,8-四苯基-1,2,5,6-tetraazocine 可以通过两摩尔苄基单腙或苄基和苄基二腙的等摩尔混合物的热缩合制备的说法已被彻底重新研究。当在潮湿空气中进行这种热解时,既没有检测到要求保护的 3,4,7,8-四苯基-1,2,5,6-四氮杂辛,也没有检测到前面提到的异构四氮杂戊烯衍生物。加热熔融的苄基一腙(%)明确形成以下产物:苄基(10)、苯甲醛(10)、苯甲酰胺(22)、苄基苯基酮(19)、苄基双(酮嗪)(11)、3、 4,5,6-四苯基哒嗪 (9)、苄基苯甲醛吖嗪 (10) 和柱色谱后的 2,4,5-三苯基咪唑 (2)。这最后一个组分具有熔点和紫外光下的荧光特性,最初的研究人员将其归因于错误地假定为 3,4,7,8-四苯基-1,2,5,6-tetraazocine。因此,关于合成这种新型四氮杂辛环或什至合成先行的异构两性离子四氮杂戊烯的原始权利要求现已被否定。2,4,5