35011-47-3

yellow-beige crystalline powder

2,4,5-Triamino-6-hydroxypyrimidine sulfate is used in the preparation of guanines and other purine derivatives with antiviral activities.

This salt has very low solubility in H2O. It is best purified by conversion into the dihydrochloride salt, which is then re-converted to the insoluble sulfate salt. The sulfate salt (2.57g, 10mmoles) is suspended in H2O (20mL) containing BaCl2 (10mmoles) and stirred in a boiling water bath for 15minutes. After cooling, the insoluble BaSO4 is filtered off and washed with boiling H2O (10mL). The combined filtrate and washings are made acidic with HCl and evaporated to dryness. The residual hydrochloride salt is recrystallised from H2O by adding conc HCl whereby the dihydrochloride salt separates as clusters which darken at 260o and dec > 300o[darkening > 360o]. [Baugh & Shaw J Org Chem 29 3610 1964, King & Spengley J Chem Soc 2144 1952]. The hydrochloride is then dissolved in H2O, and while hot an equivalent of H2SO4 is added when the sulfate separates as a white microcrystalline solid which is filtered off washed liberally with H2O and dried in vacuum over P2O5. [Albert & Wood J Appl Chem London 3 521 1953, UV: Cavalieri et al. J Am Chem Soc 70 3875 1948; see also Pfleiderer Chem Ber 90 2272 1957, Traube Chem Ber 33 1371 1900.] The hydrochloride has m > 300o. [Beilstein 25 II 384, 25 III/IV 3648.]