Low temperature nitrations of 2-methylimidazole gave in addition to th
e known 2-methyl-5(4)-nitroimidazole (1), 2-(dinitromethylene)-5,5-din
itro-4-imidazolidinone (3) and parabanic acid (2). The tetranitro comp
ound 3 was also obtained by nitration of 2-methyl-4,5-dihydro-( 1H)-5-
imidazolone (:8). Thermal decomposition of 3 gave 2-(dinitromethylene)
-4,5-imidazolidinedione (4) which also was the product from nitration
of the new compound 2-methoxy-2-methyl-4,5-imidazolidinedione. Treatme
nt of 4 with aqueous ammonia gave the previously unknown 1,1-diamino-2
,2-dinitroethylene (5). The physical properties and chemical behaviour
of (5) are described. (C) 1998 Published by Elsevier Science Ltd. All
rights reserved.