反应详情

136 g (0.5 mol) of N,N-dimethylguanidine sulphate were added to a solution of 162 g (3 mol) of sodium methylate in 1 l of methanol at 0° to 5° C. 160 g (1 mol) of malonic acid diethyl ester were then allowed to run in without cooling and the mixture was stirred for 24 hours at room temperature. The solvent was then distilled off in vacuo and the residue was dissolved in water. The solution was brought to approximately pH 5 by adding glacial acetic acid; it was then cooled to 0°-5° C and the product which had precipitated was filtered off. 75 g (48% of theory) of 2-dimethylamino-4,6-dihydroxypyrimidine were thus obtained in the form of a colorless powder of melting point > 300° C.

1. temperaturewithout cooling
2. distillationThe solvent was then distilled off in vacuo
3. dissolutionthe residue was dissolved in water
4. additionby adding glacial acetic acid
5. temperatureit was then cooled to 0°-5° C
6. customthe product which had precipitated
7. filtrationwas filtered off