作者:Nikolay T. Tzvetkov、Christa E. Müller
DOI:10.1016/j.tetlet.2012.07.140
日期:2012.10
An efficient approach for the formation of 5-amino- and 7-amino-6-azaoxindole derivatives was developed. 2-Amino-4-chloro-3-nitropyridine (8), and its 5-nitro-substituted regioisomer (9), respectively, were obtained by reaction with ethyl malonate. The resulting 2-amino-3/5-nitropyridine derivatives substituted in the 4-position with malonic acid diethyl ester (10, 11) were subjected to reductive cyclization
开发了形成5-氨基-和7-氨基-6-氮杂吲哚衍生物的有效方法。通过与丙二酸乙酯反应,分别获得2-氨基-4-氯-3-硝基吡啶(8)及其5-硝基取代的区域异构体(9)。在4-位用丙二酸二乙酯取代的(将得到的2-氨基五分之三硝基吡啶衍生物10,11)进行还原性环化,得到3-乙氧羰基-6-氮杂羟基吲哚衍生物4A和5A。不需要保护氨基功能。中间体10和11也可以转化为相应的4-乙酸乙酯1213和13通过用LiCl脱烷氧羰基化,然后在还原条件下环化,得到3-未取代的5- / 7-氨基恶二吲哚。