Preparation of nitrourea
Alternative Names: N-Nitrocarbamide; Nitro-urea; Nitro urea; 1-Nitrourea;
Nitrourea is prepared by adding 200 g of dry urea nitrate in small portions at a time with gentle stirring to 300 ml of concentrated sulfuric acid (d=1.84 g/ml) while the temperature of the mixture is kept below 0° C. The milky liquid is poured without delay into a mixture of ice and water (1 liter), the finely divided white precipitate is collected on a filter, sucked as dry as may be, and, without washing, is immediately dissolved while still wet in boiling alcohol. The product at this point contains acid enough to prevent it from decomposing in boiling alcohol (for a second recrystallization it is unsafe to heat the alcohol above 60° C). The liquid on cooling deposits pearly leaflets of nitrourea. It is chilled and filtered, and the crystals are rinsed with cold alcohol and dried in the air. The product, which melts at 146° C to 153° C with decomposition, is sufficiently pure for use in synthesis, and may be preserved for several years unchanged in hard glass bottles. If slightly moist nitrourea is allowed to stand in contact with soft glass, that is, in contact with a trace of alkali, it decomposes completely within a short time forming water, ammonia, nitrous oxide, urea, biuret, cyanuric acid, etc. Pure nitrourea, recrystallized from benzene, ether, or chloroform, in which solvents it is sparingly soluble, melts with decomposition at 158.4-158.8° C. In water and in hydrophilic solvents nitrourea dearranges rapidly into cyanic acid and nitroamide. Alkalis promote the reaction. If an aqueous solution of nitrourea is warmed, bubbles of nitrous oxide begin to come off at about 60° C.
Chemistry of Powder and Explosives, by T. L. Davis, 373-374, 1941
Nitrourea, 556-89-8, N-Nitrocarbamide, nitro-urea, Nitro urea, 1-Nitrourea, UREA, NITRO-, Urea, N-nitro-, N-Nitrourea, NSC14982, AC1L1WZP, Ex170, SCHEMBL304553, UNII-3UA35787YZ, CTK1G9728, CMUOJBJRZUHRMU-UHFFFAOYSA-N, MolPort-001-779-753, 3UA35787YZ, EINECS 209-144-0, NSC 14982, NSC-14982, UN0147, AKOS015919402, MCULE-8786265489, AN-45910, KB-58431, OR022878, OR284515, SC-84439, DB-052775, N0328, Nitro urea [UN0147] [Explosive 1.1D], A830756, S05-0155, 3B3-051790