Studies on 1,3-benzoxazines. VI. Formation of quinazolines and 4H-3,1-benzoxazines by the reaction of 4-chloro-2H-1,3-benzoxazines with aminoacetophenone, aminobenzophenone and aminobenzyl alcohol derivatives.
作者:RYUJI TACHIKAWA、KAZUYUKI WACHI、ATSUSUKE TERADA
DOI:10.1248/cpb.30.559
日期:——
A novel synthetic method for quinazoline and 4H-3, 1-benzoxazine derivatives is described. Reaction of 4-chloro-2H-1, 3-benzoxazine (1) with 2-aminoacetophenone (2a) gave rise to the quinazoline derivative (4a) in good yield, while treatment of aminobenzophenones (2b-e) with 1 afforded only substituted compounds (3b-e), which could be converted into quinazoline derivatives (4b-e) on heating in the presence of p-toluenesulfonic acid in toluene. Derivatives of 4H-3, 1-benzoxazines (10a-e) were prepared by the reaction of the aminobenzyl alcohols (7a-e) with 1. A possible mechanism for the formation of these reaction products is discussed.
报道了一种合成喹唉和4H-3,1-苯并氧嗪衍生物的新方法。4-氯-2H-1,3-苯并氧嗪(1)与2-氨基乙酰苯(2a)反应,以良好收率得到喹唑啉衍生物(4a),而氨基苯乙酮(2b-e)与1反应仅得到取代化合物(3b-e),这些化合物在甲苯中加热时可以转化为喹唑啉衍生物(4b-e)。4H-3,1-苯并氧嗪衍生物(10a-e)是通过氨基苄醇(7a-e)与1的反应制备的。讨论了这些反应产物形成的可能机理。