Trifluoro-3-hydroxy-1<i>H</i>-indazolecarboxylic Acids and Esters from Perfluorinated Benzenedicarboxylic Acids
作者:Carlos Pérez Medina、Concepción López、Rosa M. Claramunt、José Elguero
DOI:10.1002/ejoc.200901102
日期:2010.2
Twelve new 3-hydroxyindazoles, each bearing three fluorine substituents and a CO 2 R group (R = H, CH 3 , C 2 H 5 ) distributed around its 4-, 5-, 6-, and 7-positions, have been synthesized. They were studied by NMR in solution ( 1 H, 13 C, 15 N, 19 F) and in the solid state ( 13 C, 15 N). In solution, all of them are 3-hydroxy tautomers: the a form. In the solid state, although the 3-hydroxy tautomers
已经合成了 12 个新的 3-羟基吲唑,每个都带有三个氟取代基和一个分布在其 4-、5-、6-和 7-位周围的 CO 2 R 基团(R = H、CH 3 、C 2 H 5 ) . 通过NMR在溶液( 1 H, 13 C, 15 N, 19 F)和固态( 13 C, 15 N)中研究它们。在溶液中,它们都是 3-羟基互变异构体:a 形式。在固态下,虽然 3-羟基互变异构体仍然是最常见的,但也有一些 indazolin-3-ones - b 型 - 和一个非常罕见的例子 (12ab),其中两种互变异构体都存在。