13566-71-7

1670-14-0

108-59-8

13566-71-7

Benzamidine hydrochloride (26.0 g, 0.166 mol) and dimethyl malonate (21.9 g, 0.166 mol) were dissolved in anhydrous methanol (200 mL). A methanolic solution of 30% sodium methanol (89.7 g, 0.498 mol) was slowly added under stirring conditions and sodium chloride precipitation was observed to be generated during the reaction. The reaction mixture was stirred continuously at 55°C for 2 hours. After completion of the reaction, the reaction mixture was diluted with water (500 mL) to obtain a clarified solution. Subsequently, it was acidified by dropwise addition of acetic acid (35 mL) and a white precipitate was rapidly precipitated. After continued stirring for 30 min, the solid product was collected by filtration. The filter cake was washed sequentially with water, methanol and acetone and dried to give 2-phenylpyrimidine-4,6-diol in a yield of 25 g (80% yield) as a white solid.