Covalent hydrates as intermediates in heterocyclic rearrangements. Part II. The hydrolysis of 2-amino-6-methyl-4-n-propyl-s-triazolo-[1,5-a]pyrimidin-5 (4H)-one

Abstract

The title compound is hydrolysed in aqueous alkali to products, some of which have been isolated and identified, via an intermediate that has not. Circumstantial evidence (pK_a, u.v. spectrum) is presented for the structure (4) suggested for this intermediate, which if correct is formed in a mechanistically reasonable way. The rate of formation of this intermediate varies with [OH^–]². Comparisons are drawn with the stable compound (8).