Preparing Salts of Dinitromethane

Latypov etal, US Patent 6,340,780 (January 22, 2002) Assignee Totalfursvarets Forkiningsinstitut Utility Energetic Chemical Agents and Intermediates 

Barbituric acid (5g) was dissolved in 40 ml 95% H2SO4 followed by the addition of concentrated HNO3 (8.5 g) and the reaction temperature kept at 40 °C. After 3 hours a copious amount of white precipitate formed and was filtered. The precipitate was washed with trifluoroacetic acid, dried under vacuum, and the product isolated in 80% yield. 

The product from Step 1 was dissolved in 30 ml ice water, the solution neutralized with 20% KOH, and the mixture heated to 80 °C 2 hours. Upon cooling, a precipitate formed and was isolated. It was re-crystallized and the product isolated in 70% yield. UV absorption data supplied. 

Ammonium dinitromethane was also prepared by the author in Step 2 using 25% ammonium hydroxide solution. 

When the author nitrated 4,6-dihydroxy-2-methylpyrimidine with mixed acids and the intermediate hydrolyzed, equal amounts of potassium dinitromethane and 1,1-diamine-2,2-dinitroethene were formed. 

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