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 (pKa, 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).