The general procedure for the synthesis of 2-amino-4-hydroxy-6-methylpyrimidines from ethyl acetoacetate and the compound (CAS: 113-00-8) was carried out as follows: referring to the literature method [26] with slight modifications. Guanidine (2.02 g, 33.84 mM) was dissolved in acetone/ethanol solvent mixture (1:2, v/v) and an acetone/ethanol solution of ethyl acetoacetate (4.40 g, 33.86 mM) was added slowly and dropwise. The reaction mixture was stirred at room temperature for 10 hours. After completion of the reaction, the solid product was isolated by filtration and recrystallized from acetic acid to obtain colorless crystals. Yield: 1.36 g (52%). The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3, ppm): δ 11.09 (s, 1H, OH), 5.92 (s, 2H, NH2), 5.14 (s, 1H, Ar-H), 2.14 (s, 3H, Ar-CH3).13C NMR (100 MHz, CDCl3, ppm) data: δ 162.3, 161.1, 155.3, 102.5, 23.9. ESI-MS analysis: calculated value C5H7N3O [M+] is 125.06; measured value is 126.07 [M++1].
