A facile synthesis of 4-, 6- and 7-formyl-1<i>H</i>-indole-2-carboxylates: The CH<sub>2</sub>SO<sub>3</sub>H functionality as a masked formyl group
作者:Béla Pete、Bálint Szokol、Áron Szöllőy
DOI:10.1002/jhet.5570430528
日期:2006.9
intermediates, ethyl 4-, 6- and 7-formyl-1H-indole-2-carboxylates (10, 11, 12) were prepared from 2-ethoxycarbonyl-1H-indole-4-, 6- and 7-methanesulfonic acids (1, 2, 3), respectively. The transformation of sulfomethyl group to formyl function was accomplished through elimination of SO2 to yield ethyl 4-, 6- and 7-chloromethyl-1H-indole-2-carboxylates (4, 5, 6), hydrolysed to ethyl 4-, 6- and 7-hydroxymet
由2-乙氧基羰基-1 H-吲哚-4-,6-和2-乙氧基羰基化合物制备有价值的新型合成中间体4-,6-和7-甲酰基-1 H-吲哚-2-羧酸乙酯(10、11、12)。7-甲磺酸(1、2、3)。磺甲基向甲酰基官能团的转化是通过消除SO 2来完成的,得到4-,6-和7-氯甲基-1 H-吲哚-2-羧酸乙酯(4、5、6),水解为4-乙基, 6和7-羟甲基-1 H-吲哚-2-羧酸盐(7,8,9),然后氧化为醛(10,11,12)。不需要在N1处保护吲哚。与4-和6-(氯甲基)吲哚相比,观察到7-氯甲基吲哚的水解速率显着增加。