No abstract

No abstract

No abstract

Nitration of some 2-substituted pyrimidine-4,6-diones in sulfuric acid was studied, which afforded previously unknown 5,5-gem-dinitropyrimidine-4,6-diones in high yields. The gem-dinitro products were easily attacked by nucleophiles with concomitant formation of gem-dinitroacetyl derivatives, which in turn could be further hydrolyzed to salts of dinitromethane and triureas.

Nitration of 4,6‐dihydroxypyrimidine in sulphuric acid gave nitroform as the sole product. This behaviour was tentatively explained by the formation of an intermediate, 5,5‐dinitro‐4,6‐dihydroxypyrimidine, that underwent hydrolysis in the nitrating acid to gem‐dinitroacetyl formamidine. This compound was further nitrated in the same reaction mixture to trinitroacetylformamidine which finally underwent hydrolytic cleavage to nitroform. It was also demonstrated that gem‐dinitroacetyl ureas were able to produce nitroform on nitration. The structures of the proposed trinitroacetylureas were confirmed by the isolation of one of their derivatives.