Nitrocarbamates

Nitrocarbamates. Salts of Nitrocarbamic Acid. See under Carbamic Acid and Derivatives in Vol 2, C40-Lff... 

Nitramine (161), the simplest member of the nitramines, can be prepared from ethyl carbamate (158) in three synthetic steps nitration of the latter with mixed acid or a solution of ethyl nitrate in concentrated sulfuric acid, followed by isolation of the resulting ethyl N-nitrocarbamate as the ammonium salt (159), hydrolysis with aqueous potassium hydroxide and subsequent acidification, yields nitramine (161). ... 

Methylnitramine (1) has also been synthesized from the hydrolysis of ethyl Ai-methyl-A -nitrocarbamate (163), Al,Al -dinitro-Ai,Ai -dimethyloxamide (9) and A Ai -dinitro-Ai.Al -dimethylurea (165) " the latter, synthesized from the mixed acid nitration of N,N -dimethylurea (164), has been suggested as a possible industrial route to methylnitramineX" ... 

The reaction of substituted diazomethanes with ethyl Ai-nitrocarbamate, followed by hydrolysis of the ethyl N-alkyl-N-nitrocarbamate, has been used to prepare some primary arylnitramines where aromatic ring nitration is not required, and so limits the use of conventional N-nitrating agents.The method has not been fiilly investigated. 

Chloronitroamines and the derived A-chloro-7/-nitrocarbamates are explosive compoimds and decompose rapidly in storage. 

N-chlorocarbamic acid methyl ester 2 C41-C42 mononitrocarbamic add 2 C40 nitrocarbamic acid ethyl ester 2 C41 nitrocarbamic acid methyl ester 2 C42 nitrosocarbamic acid methyl ester 2 C42... 

Many compounds have been tested as ignition quality improvers—additives which shorten the ignition delay to a desirable duration. An extensive review in 1944 (6, 43) listed 303 references, 92 dealing with alkyl nitrates and nitrites 61 with aldehydes, ketones, esters, and ethers 49 with peroxides 42 with aromatic nitro compounds 29, with metal derivatives 28 with oxidation and oxidation products 22 with polysulfides 16 with aromatic hydrocarbons nine with nitration and four with oximes and nitroso compounds. In 1950, tests at the U. S. Naval Engineering Experiment Station (48) showed that a concentration of 1.5% of certain peroxides, alkyl nitrates, nitroaikanes, and nitrocarbamates increased cetane number 20 or more units. 

AgCaH3N203, yel powd, dec quickly in light, expl on heating, by impact or friction(Refs 1 2) Refs l)Beil 3, 123 2)J.Thiele F.Dent, Ann 302, 251(1898) JCS 76 I, 14 15(1899) Nitrocarbamic Acid Methyl Ester Carbomethoxyni-tramine of Nitrourethylan, 02N-NH-C00 CH3 mw 120.07, N 23.33% col pltlts or prisms, mp 88°, dec ca 120° 30° was ptepd by nitration of urethylan(carbamic acid methyl ester) with ethyl nitrate H2S04 below -5°(Refs 1 2) and by other methods(Ref 3)... 

Carboethoxynitramine. See Nitrocarbamic Acid Ffhyj Pgrpf under Csrb isic Acid sind Derivajives... 

Carboethoxynitrosamine, See Nitrocarbamic Acid Ethyl Ester under Garbamic Acid and Derivatives... 

Nitroamide, the simplest of the nitroamines, is formed by the action of dilute acid on potassium nitrocarbamate, which itself results from the nitration of urethane and the subsequent hydrolysis of the nitro ester by means of alcoholic potassium hydroxide. 

In 1894, J. Thiele and A. Lachman 10 prepared nitramide, nr nitroxyl amide, NH2.N02, i.e. H2N202, isomeric with hyponitrous acid. They found that by adding a soln. of potassium hydroxide to a cone. aq. soln. of nitrourethane, N02.NH.C00C2H5, at 0°, potassium nitrocarbamate, N02.NH.C00K, separates... 

The method employed is essentially the same as that first proposed by Thiele and Lachman1 but has been modified in several details, the most important change involving the manner of extracting2 the nitramide from aqueous solution. The purity and yields are markedly affected by slight changes in procedure consequently exact directions are given in considerable detail. Potassium nitrocarbamate and nitramide are best made under conditions of low temperature and low humidity. Contact with cork and rubber should be avoided wherever possible. 

Potassium nitrocarbamate is a very unstable compound, affected by moisture, heat, and carbon dioxide. It sometimes decomposes spontaneously. It should, therefore, be prepared in no larger quantity than provided for above and stored in a vacuum desiccator over potassium hydroxide in a refrigerator. 

Potassium nitrocarbamate (9.1 g.) is weighed on glazed paper and, with the aid of a porcelain or platinum spatula, is added in very small portions to the cold dilute sulfuric acid. The solution is swirled continuously. Whenever the ice melts, the flask is immersed in the cold bath until ice again forms. 

Neodymium amalgam, 15 Neodymium chloride, anhydrous, 32 Nitramide, 68, 72 Nitrocarbamate, potassium, 70 Nitrocarbamates, 68 Nitrogen, pure, 79 Nitrogen trichloride, 65 analysis of, 67 Nitrosyl chloride, 55 analysis of, 57 Nitrosylsulfuric acid, 55 Nitrourethane, 69 ammonium, 69... 

Potassium metaperiodate, 171 Potassium nitrocarbamate, 68, 70 Potassium trioxalatoaluminiate, 36 Potassium trioxalatochromiate, 37 Potassium trioxalatocobaltiate, 37 Potassium trioxalatoferriate, 36... 

Nitrodioxalatotriammineeobalt-(III), formation of, from trini-trotriamminecobalt(III), 6 191 Nitrocarbamates, 1 68-70 Nitrogen, pure, azides for preparation of, 1 79... 

Potassium nitridorhenate, 6 167 Potassium nitridotrisulfate, 2 182 Potassium nitrocarbamate, potassium salt, 1 68, 70 Potassium V-nitrosohydroxylamine-V-sulfonate, 5 117 by metathesis, 6 120 Potassium octacyanomolybdate(IV) 2-hydrate, 3 160 Potassium osmiamate, 6 204... 

Nitramide can be prepared by the decomposition of potassium nitrocarbamate in an acidic medium ... 

Other preparations include the hydrolysis of nitrocarbamic acid (316), the reaction of NaSOs NH2 with concentrated nitric acid, (317) and the reaction of N2O5 with two equivalents of ammonia (318) (see Scheme 34). 

C7H14 trans-2-heptene 14686-13-6 371.10 31.726 1,2 11815 C7H14N204 ethyl N-tert-butyl-N-nitrocarbamate 55696-02-1 554.15 49.111 2... 

The thermal decompositions of A-nitroamides and A -nitrocarbamates were found to be first order . Arrhenius parameters are shown in Table 31. In both cases the rates of decomposition increase with increasing size of the alkyl substituent, but carbamate derivatives were more stable than amides. In the case of nitrocarbamates, resonance stabilization in the ground state leads to an increase in the energy of activation leading to decomposition via a 4-centred transition state, viz. 

---