Nitrourethanes

N 36.83%, OB to C02 -42.1% colorless needles from ether nip 38° d 1.243 at 49/4° RI 1.4616 at 48,6°. V sol in cold w, ale, chlf and benz less sol in eth and still less sol in petr eth. Can be prepd by nitrating n-methyl-urethane with abs nitric acid. The resulting soln of methyl nitrourethane is drowned in w, neutralized with Na carbonate, and extrd with eth to remove methyl nitrourethane. On passing ammonia gas thru the eth extract, a white ppt of the ammonium salt of methylnitramine is deposited and sepd by filtration. It is disd in ale and boiled to drive off the ammonia, and... 

The reaction of the nitrourethane ion with hydroxide ions can be written as... 

Diaminobiuret has been prepared only from N-tricarboxylic ester and hydrazine hydrate.1 Ethyl hydrazinecarboxylate has been prepared by reduction of nitrourethan electrolytically2 or with zinc dust and acetic acid,3 and by the action of hydrazine hydrate on diethyl carbonate,4 6 ethyl chlorocarbonate,6 and N-tricarboxylic ester.1... 

A practical application of dinitrogen pentoxide in methylene chloride reagent involves the nitration of either ammonium carbamate or nitrourethane, followed by ammonolysis to yield ammonium dinitramide, an energetic oxidizer with enormous potential for use in future high performance propellant compositions. This important reaction is discussed in more detail in Chapter 9. 

Where there are strong bases which are nitrated with difficulty, reaction (9) predominates over reaction (8). At the same time Lambeiton called attention to the reversibility of reaction (9). Indeed, it is known that nitramines such as nitroguani-dine or nitrourethanes exhibit nitrating properties in the presence of sulphuric acid, thus behaving as if they can split off the nitronium ion or the nitric acid molecule. 

This is one of the simplest nitramines obtained by Thiele and Lachman [1] by the decomposition of nitrourethane ... 

A carefully-devised method for preparing it was announced by Marlies, La Mer and Greenspan [5]. According to Bell and Wilson [6] the product contains some acidic impurities (about 1 %), possibly unchanged nitrourethane. 

Ref Beil 4, 254, [693] 15321 NfN -Dinitro-NfN -dicarboethoxyethylenedi-amine 1,4-Dinitro-l,4-dicarboxy-1,4-diaza-butone or Ethylene-bis-nitrourethane (called N.N -Dinitro-N.N -dicarbathoxy-athylendiamin or N.N -Dinitro-athylendiurethan in Ger), C2H500C.N(N02).CH2.CH2.N(N02).C00C2H5 mw 294.22, N 19.04% fine ndls (from w), mp 83-84° sol in chlf benz si sol in ale almost insol in cold w prepd by nitrating ethylenediurethane with the strongest coned HNO3... 

W.C.Fernelius, ChemRevs 12, 67(1933) 20,413(1937) 3)Franklin(l935), 54-5 4)Inorg-Synth 1(1939) 74-7 2(1946), 128-35 Nitramide or Nitroxyl amide, 02N.NH2, raw 62.03, N 45.1755. Wh solid, mp 72-5° with de-compn puffs off on rapid heating. Sol in w (slowly dec) and in common solvents, except petr ether. Was first, prepd in 1890 by Mathieu-Plessy but not properly identified. Thiele Lachman prepd it in 1894(Refs 1,2 3) from nitrourethane,OaN.NHCOO.CaHs, and described its props. Since then nitramide was prepd by various investigators, mostly by hydrolysis and decarboxylation of potassium —N —... 

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 solution is cooled to — 5°C., and 110 g. (100 ml.) of ethyl nitrate is added. The mixture, is agitated for 1) hours. It is then poured slowly over 1.5 kg. of cracked ice, being stirred continuously. The solution is extracted six times with 200-ml. portions of U.S.P. ethyl ether in a large separatory funnel. The ethereal solution contains the nitrourethane together with a considerable quantity of impurities. 

A mixture of 100 ml. of concentrated sulfuric acid and 300 g. of cracked ice is now added to the foregoing ammoni-acal solution the resultant solution must be acid to Congo red. It is extracted six times with 200-ml. portions of alcohol-free ether, and the combined ethereal extracts are dried over anhydrous calcium chloride. This operation further purifies the nitrourethane which is then again converted to the ammonium salt. 

The ether solution of nitrourethane is filtered into a 4-1. flask or beaker and is diluted to 3 1. with anhydrous alcohol-free ether. The solution is then saturated with dry ammonia gas or treated with an excess of liquid ammonia, thereby precipitating ammonium nitrourethane. The product is filtered on a large Buchner funnel, washed with a small quantity of alcohol-free ether, f and dried by drawing air through the filter cake. Theoretical yield 170 g. actual yield 80 to 95 g. (47 to 55 per cent of theory). 

Ammonium nitrourethane is a white, crystalline solid and is quite stable in air. It may, therefore, be prepared in large quantity and stored at room temperature in an ordinary bottle. 

Fifty grams of powdered ammonium nitrourethane is added to a mixture of 100 ml. of water and 100 ml. of... 

Acetic acid-acetic anhydride, 85 Alkali azides, 79 Alkaline earth azides, 79 Alumino-oxalates, 36 Amalgams, 5 concentration of, 17 preparation of, 6 rare earth metal, 15 Ammonium nitrourethane, 69 Ammonium perrhenate, 177 Antimony oxyiodide, 105 Antimony triiodide, 104 Aquopentammino cobalti bromide, 187, 188... 

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... 

Nitrosylpentamminecobalt(III) chloride, pink, 4 168 [shown to be chloropentamminecobalt-(III) chloride], 6 185 Nitrosyls, nomenclature of, 2 264 Nitrosylsulfuric acid, 1 55 Nitrourethan, and ammonium salt, 1 69... 

The SRI researchers later introduced an approach whereby ammonium nitrourethane can be nitrated with N2O5 or NO2BF4 to give dinitrourethane. In a subsequent step, the urethane is cleaved with ammonia resulting in ADN. This route has been used in the US in scaled-up... 

N02C4H Butyl nitrite, 2 139 NO2CI Nitryl chloride, 4 52 NO2NHCO2C2H6 Nitrourethan, 1 69... 

N02N(NH4)C02C2H6 Ammonium salt of nitrourethan, 1 69 N03H Nitric acid, 3 13 4 52 N(S03K)s Potassium nitridotri-sulfate, 2 182... 

The addition of N-nitrourethanes 429 to carbodiimides also afforts insertion products 430. ... 

A series of benzylnitramines were prepared by either nitration of the carbamates or N-alkylation of nitrourethane, followed by ammonolysis. These represent one-phenylnitramines, known broadleaf herbicides. Nastic responses and growth inhibition observed for this class suggested similarity to the auxin type herbicides. To determine if die preference for the (R) -configuration extended to nitramines, l-(2 6 -dichlorophenethyl)nitramine was resolved and the absolute configuration determined by asymmetric synthesis. A comparison of the (+) and (-) isomers in herbicidal and in vitro assays was performed and the results are discussed. 

In its application to catalysts, the preceding paragraph suggests that pseudo-acids or bases will be ineffective catalysts compared with other acids or bases of the same strength i.e., they should exhibit negative deviations from the Bronsted relation. There are a number of isolated observations which confirm this idea. Thus Bronsted and Pedersen (15) found that the nitrourethane ion had an unexpectedly small catalytic... 

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