Three new functional 2-substituted 1,3-dinitroimidazolidines were synthesized herein. A synthetic strategy is suggested for structurally different alpha,alpha-dinitraminocarboxylic acids via condensation of glyoxylic acid ethyl ester with amine or amide derivatives. Alkali- and acid-catalyzed hydrolyses of ethyl 1,3-dinitroimidazolidine-2-carboxylate were studied. A series of hydrolysis products were isolated. The Curtius rearrangement of 1,3-dinitroimidazolidine-2-carboxylic acid to 2-isocyanato-1,3-dinitroimidazolidine was carried out. Hydrolyses of 1,3-dinitroimidazolidine-2-carbonyl azide and 2-isocyanato-1,3-dinitroimidazolidine were studied. 1,3-Dinitroimidazolidine-2-amine was captured as 1,3-bis(1,3-dinitroimidazolidin-2-yl)urea.