Cyclization of N-acylanthranilic acids with Vilsmeier reagents. Chemical and structural studies
作者:Jan Bergman、Claes Stålhandske
DOI:10.1016/0040-4020(95)01035-1
日期:1996.1
Vilsmeier reagents, generated from e.g. N, N-dimethylformamide and oxalyl chloride, react with N-acetylanthranilic acid to produce the 2-(2′-dimethylamino)ethenyl-4H-3,1-benzoxazin-4-one13a.. N-phenylacetylanthranilic acid similarly gave 2-(2′-dimethylamino-1′-phenyl)ethenyl-4H-3,1-benzoxazin-4-one6a, whose structure has been determined by X-ray crystallography. The benzoxazinone 6a could readily be
维尔斯迈尔试剂,例如从产生Ñ,Ñ二甲基甲酰胺和草酰氯,与之反应Ñ -acetylanthranilic酸,以产生2-(2'-二甲基氨基)乙烯基-4H-3,1-苯并恶嗪-4-酮13A .. ñ -苯基乙酰基邻氨基苯甲酸类似地给出了2-(2'-二甲基氨基-1'-苯基)乙烯基-4 H -3,1-苯并恶嗪-4-酮6a,其结构已经通过X射线晶体学确定。苯并恶嗪酮6a中可以很容易地转化为稠合的杂环系统,从而例如图13A和水合肼,得到吡唑并[5,1-B] -4 ħ -喹唑啉20A。N的反应-乙酰化的邻氨基苯甲酸和草酰氯单独给出了稠合的恶唑烷-4,5-二酮24。通过X射线晶体学确定了一个代表24a的结构。消除CO + CO 2后,24a的热解以定量收率得到2-苄基-4H-3,1-苯并恶嗪-4-one 7。