The action of alkali on some purines and their derivatives

Abstract

On treatment of purines and their nucleosides and nucleotides with N-alkali at 100° for 1 hr., three types of reaction occurred: (1) opening of the imidazole ring to give finally a derivative of 4,5-diaminopyrimidine, (2) hydrolysis of the glycosidic linkage to give a free purine, (3) replacement of –NH₂ or –Cl in the purine ring by –OH. In general, for reaction to occur, the compound must not have an anionic group in the purine ring. Thus, all the free purines tested, except 6-chloropurine (which was partly converted into hypoxanthine) were stable, as were the nucleosides derived from guanine, xanthine, and hypoxanthine (except deoxyinosine, which was very slightly hydrolysed). Adenine-containing nucleosides were partly degraded to 4,5,6-triaminopyrimidine, and 6-chloro-9-(tetrahydropyran-2-yl-)purine gave 4,5-diamino-6-chloropyrimidine.