Synthesis
The synthesis of 2-Amino-4,6-dihydroxypyrimidine is as follows:
A freshly-prepared sodiummethoxide solution in methanol (25 ml) was added to a round-bottomed flask containing guanidine hydrochloride(15 mmol), stirred for a few minutes, before dimethyl malonate (15 mmol)was slowly added. The mixture was heated under reflux for about 2-3hours. After evaporation of the solvent under reduced pressure, the resultingwhite solid was dissolved in a minimum amount of water and the pH adjusted to 6with 10% HCl. The precipitate obtained was filtered and washed with distilledwater and ethanol, respectively, to obtain pure 2-amino-4,6-pyrimidinediol.(Note: sodium methoxide solution was prepared by addition of small pieces ofsodium metal in methanol).Yield: 85%;solid, m.p. 195-197 °C.