Steric hindrance to the syntheses and stabilities of 1,5- and 2,6-naphthalene N-permethylated diammonium salts
作者:Đani Škalamera、Liping Cao、Lyle Isaacs、Robert Glaser、Kata Mlinarić-Majerski
DOI:10.1016/j.tet.2016.02.002
日期:2016.3
A series of naphthalene-1,5- and 2,6-diamines and their N-methyl derivatives were synthesized and characterized. 1H NMR spectroscopy showed that an aqueous solution of naphthalene-2,6-di(NMe3I) (2) underwent considerable demethylation over a 24 h period after its initial preparation. Exchange of the iodide nucleophilic anion by the triflate non-nucleophilic counter-ion afforded a stable quaternary
合成并表征了一系列萘-1,5-和2,6-二胺及其N-甲基衍生物。1 H NMR谱显示,萘-2,6-di(NMe 3 I)(2)的水溶液在初始制备后的24小时内经历了相当大的脱甲基。三氟甲磺酸盐非亲核抗衡离子交换碘化物亲核阴离子可得到稳定的季铵盐。萘2,6-di(NH 2 MeCl)(3 ·HCl)和萘2,6-di(NHMe 2 Cl)(4 ·HCl)在D 2 O溶液中的H / Dα-位置交换+ N H观察到质子,但没有观察到萘-2,6-di(NMe 3 I)或三氟甲磺酸盐(2或5)的质子。萘-1,5-二(NMe 2)的详尽的全N甲基化(7)仅由于严重的1,8而提供了混合的萘-1-NMe 3 I-5-NHMe 2 I季铵-叔铵盐。型周应变。