New 1,2,4-triazine-containing podands: synthesis and properties

Abstract

A method of one-step C-C coupling of 1,5-bis(2,6-dimethylphenoxy)-3-oxapentane (1a) and 1,8-bis(2,6-dimethylphenoxy)-3,6-dioxaoctane (1b) with 3-methylthio- (2) and 3-amino-1,2,4-triazine (3) and 3-aryl-1,2,4-triazin-5-one (6-8) has been described. The reaction of compounds 1a,b with compounds 2 and 3 in the presence of trifluoroacetic acid results in the addition of the dimethylphenoxy group to the unsubstituted C(5) carbon atom of the triazine ring. The reactions of triazinones 6-8 with compounds 1a,b in a mixture of trifluoroacetic acid and organic anhydrides are accompanied by the acylation of the nitrogen atom adjacent to the reaction center and affords bis[(3-R-1-acyl-5-oxo-1,4,5,6-tetrahydro-1,2,4-triazin-6-yl)-2,6-dimethylphenoxy]-3-oxapentane or -3,6-dioxaoctane. The obtained adducts can smoothly be oxidized under mild conditions to form more stable products of nucleophilic hydrogen substitution in the triazine ring. The extraction and transport of Ca²⁺ and Mg²⁺ cations through an organic membrane by the compounds synthesized are discussed.