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, which is used as a primary product for producing an explosive - 1,1-diamino-2,2-dinitroethylene (DADNE, FOX-7), and can also be used in synthesis of biologically active substances. The method involves reacting a sodium alcoholate with malonediamide and ethyl acetate in an alcohol medium, followed by evaporation of the solution, dissolution of the residue in water and acidation. The sodium alcoholate used is dry sodium methylate, which is mixed with isopropyl alcohol as the alcohol medium to obtain a solution which is successively treated with malonediamide and ethyl acetate while boiling. The molar ratio of malonediamide to sodium methylate is 1:3.3-3.5, preferably 1:3.5, and the molar ratio of malonediamide to ethyl acetate is 1:1.3-2, preferably 1:2. Glacial acetic acid is used for acidation. Acidation of the reaction solution is carried out at temperature 50-55°C to pH 5-6.

EFFECT: method increases output of the end product, improves filterability of the precipitate and simplifies the process owing to use of readily available and safe reagents.

4 cl, 1 tbl, 6 ex