Synthesis of optically active 1,4-benzoxazinones and 1,5-benzoxazepinones by regiocontrolled ring transformations of oxirane carboxylic acids and esters with aromatic o-hydroxyarylamines
作者:Karsten Woydowski、Jürgen Liebscher
DOI:10.1016/s0040-4020(99)00488-3
日期:1999.7
o-aminophenols 2 either to 1,4-benzoxazin-2-ones 5 or to the 1,5-benzoxazepin-2-one 4 while a condensed 1,4-oxazin-3-one 6 was obtained with 2-amino-3-hydroxypyridine. On the other hand optical active oxirane carboxylic acids 7 react with o-aminophenols8 in the presence of DCC (dicyclohexylcarbodiimide) or isobutyl chloroformiate affording oxirane carboxamides 9 that can be ring transformed to either 2,3-dihydro-4H-1
对映体二乙基环氧乙烷乙烷二羧酸酯1与邻氨基苯酚2反应生成1,4-苯并恶嗪-2-酮5或与1,5-苯并恶唑啉-2-酮4反应,而缩合的1,4-恶嗪-3-酮6反应。用2-氨基-3-羟基吡啶制得。另一方面,光学活性环氧乙烷羧酸7在DCC(二环己基碳二亚胺)或氯甲酸异丁酯的存在下与邻氨基苯酚8反应,得到环氧乙烷羧酰胺9,其可以被环转化为2,3-二氢-4 H -1,4。 -苯并恶嗪-3-酮10或3-羟基-2,3-二氢-5H -1,5-苯并恶唑啉-4-酮11取决于反应条件。