Reaction of 2,4-di-tert-butylphenol with urotropin in conditions of Duff reaction takes an abnormal route and instead of the expected di-tert-butylsalicylaldehyde provides a mixture of N-substituted 3,5-di-tert-butyl-2-hydroxybenzylamines and redox conjugate benzoxazines containing mostly 6,8-di-tert-butyl-3-(3,5-di-tert-butyl-2-hydroxybenzyl)-2H-3,4-dihydrobenz[e][1,3]oxazine. A solvolysis of an individual benzoxazine in the system HO(CH2)2OH-H2O-HCl affords di(3,5-di-tert-butyl-2-hydroxybenzyl)amine, and in AcOH 3,5-di-tert-butylsalicilaldehyde. A mechanism of Duff reaction was suggested involving the formation of a benzoxazine intermediate.
2,4-二叔丁基苯酚与
尿素在达夫反应条件下的反应采取了异常路径,未能生成预期的二叔丁基
水杨醛,而是提供了N取代的3,5-二叔丁基-2-羟基苯
甲胺的混合物以及主要包含6,8-二叔丁基-3-(3,5-二叔丁基-2-羟基苯甲基)-2H-3,4-二氢苯【e】【1,3】氧杂环的氧化还原共轭物。在HO(
CH2)2OH-
H2O-HCl体系中,单一的氧杂环的溶解
水解生成二(3,5-二叔丁基-2-羟基苯甲基)胺,而在
醋酸中则生成
3,5-二叔丁基水杨醛。提出了一种达夫反应的机理,涉及到苯氧杂环中间体的形成。