Methylation of aminopyridazines

Abstract

Quaternisations of mono- and di-aminopyridazines with methyl iodide in methanol have been examined and the products identified. 3- and 4-Aminopyridazine and 3,5-diaminopyridazine gave both 1- and 2-methyl derivatives. 3,4-, 3,6-, and 4,5-Diaminopyridazines each gave a single product, which in the first case was tentatively identified as 3,4-diamino-1-methylpyridazinium iodide. No ammonio-compounds were detected in these reactions. Ionization constants, u.v. and ¹H n.m.r. spectra are recorded and discussed.