反应详情

In another experiment, 2,5-diamino-4,6-dihydroxypyrimidine hemisulfate (Sigma, 48.0 g, 0.250 mole) was reacted as in Example 1 with less Vilsmeier reagent (7.2 molar equivalents) and the resulting 4,6-dichloro-2,5-bis-{[(dimethylamino)methylene]amino}pyrimidine (92%), without recrytallizaton, was hydrolyzed in 95% ethanol (1 L) and 6 N aqueous hydrochloric acid (110 mL) to provide the title compound of the same purity (elemental analysis and 1H-NMR) as the characterized sample described above (44.2 g. 76% overall from 2,5-diamino-4,6-dihydroxypyrimidine hemisulfate).