4,6-Diamino-2-mercaptopyrimidine

17356-08-0

109-77-3

1004-39-3

Sodium methanolate (540 g, 9.98 mol) was dissolved in 2 L of methanol, followed by the sequential addition of thiourea (190 g, 2.50 mol) and malononitrile (412 g, 6.24 mol). The reaction mixture was stirred at 40 °C for 30 hours. After completion of the reaction, the mixture was cooled to room temperature and the solid was collected by filtration. The filter cake was dissolved in 3.5 L of water and the pH of the solution was adjusted with acetic acid to about 7. The solid product was collected by filtration again and dried to give 334 g of light yellow solid in 94% yield.