Competitive Cyclization in the Reaction of Hexafluoropropene with 2-Aminobenzamide
作者:Takeshi Nakai、Nabil M. Hassan、Nobuo Ishikawa
DOI:10.1246/bcsj.50.3014
日期:1977.11
The reaction of hexafluoropropene(HFP) with 2-aminobenzamide afforded 2-(1,2,2,2-tetrafluoroethyl)-4(3H)-quinazolinone (4) and N-(2-cyanophenyl)-2,3,3,3-tetrafluoropropionamide (5) in ca.1 : 1 ratio, which is essentially independent of the reaction temperatures ranging from room temperature to 100 °C. The formation of the two products is explained in terms of the competitive cyclization of the imidoyl fluoride intermediate, the N-6 and O-6 ring closures ultimately yielding 4 and 5, respectively. In contrast to the HFP reaction, 2-(trifluoromethyl)pentafluoropropene (OFIB) and 2-aminobenzamide gave only the O-6 cyclized product, N-(2-cyanophenyl)-2-trifluoromethyl-3,3,3-trifluoropropionamide. The difference in reactivity between HFP and OFIB is discussed.
六氟丙烯(HFP)与2-氨基苯酰胺反应,以约1:1的比例生成2-(1,2,2,2-四氟乙基)-4(3H)-喹唑啉酮(4)和N-(2-氰基苯基)-2,3,3,3-四氟丙酰胺(5),该比例基本上与反应温度无关,反应温度范围从室温到100°C。两个产物的形成可以用亚胺基氟化物中间体的竞争性环化来解释,N-6和O-6环化最终分别生成4和5。与HFP反应不同,2-(三氟甲基)五氟丙烯(OFIB)和2-氨基苯酰胺只生成O-6环化产物,即N-(2-氰基苯基)-2-三氟甲基-3,3,3-三氟丙酰胺。讨论了HFP和OFIB之间反应活性的差异。