METHOD OF PRODUCING 2-METHYLPYRIMIDINE-4,6-(3H,5H)-DIONE Russian patent published in 2014 - IPC C07D239/54 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of producing 2-methylpyrimidine-4,6-(3H,5H)-dione by reacting malonic ester with an acetic acid derivative in a medium of a monoatomic alcohol in the presence of sodium methylate, followed by acidation. The acetic acid derivative used is acetamide in molar ratio of malonic ester to acetamide of 1:2.9-3.2, preferably 1:3.0, and malonic ester to sodium methylate of 1:3.2-4.0, preferably 1:4.0. The monoatomic alcohol used is isopropyl alcohol and the process is carried out while boiling. The reaction mass is usually evaporated first, the residue is dissolved in water and acidified. Acidation of the 2-methylpyrimidine-4,6-(3H,5H)-dione salt solution is usually carried out at temperature of 50-60°C using glacial acetic acid.

EFFECT: method increases output of the end product and simplifies the process owing to use of a hydrolytically stable, non-toxic and industrially produced acetamide as the acetic acid derivative, as well as isopropyl alcohol.

5 cl, 1 tbl, 5 ex