Nitroguanidine, reduction

The main starting compound is the labeled nitroguanidine 257 obtained from guanidine with isotope-labeled potassium nitrate. Reduction of 257 to hydrazine carboximidamide 258 was carried out with zinc and, then, ring closure to 3-amino[l,2,4]triazole 259 was carried out using formic acid. Finally, the ring closure to form the [l,2,4]triazine ring - similar to other procedures presented in Scheme 54 - was perfected by reaction with nitrous acid followed by treatment with ethyl nitroacetate to 260. 

Hydrazine salts have been prepared by the action of hypochlorites on ammonia1 or urea 2 by the hydrolysis of salts of sulfohydrazimethylene disulfonic acid 3 by the hydrolysis of triazoacetic acid 4 by the reduction of diazoacetic ester 5 by the reduction of nitroguanidine followed by hydrolysis 6 by the reduction of the nitroso derivatives of hexamethylene tetramine 7 by the reduction of nitrates or nitrites with zinc in neutral solution 8 by the action of sodium bisulfite on hyponitrous acid... 

Compounds of type (XVIII) have been prepared by reduction of a nitroguanidine [199], by reaction of an amine with 5-methylisothiosemicarbazide [131,194,199,200], or by reaction of hydrazine with a substituted S-methyliso-thiouronium salt [131, 193]. 

Nitroguanidine is reduced to aminoguanidine 24 in good yields using aqueous sulphuric acid as electrolyte when the product precipitates as the hydrogen sulphate [124,125], Nitrourea affords semicarbazide on reduction in acid solution [126]... 

On reduction, nitroguanidine is converted first into nitrosoguanidine and then into aminoguanidine i.e. guanylhydrazine. The latter is used for the manufacture of tetrazene (p. 206), and in organic chemistry to form crystalline derivatives from aldehydes and ketones, just as semicarbazide forms semicarbazones. 

According to these authors, nitrosoguanidine is prepared by the reduction of nitroguanidine with zinc dust in a neutral medium, in the presence of ammonium chloride at room temperature (below 20-25°C). The product is filtered off together with a precipitate of zinc oxide and zinc salt, from which it is then extracted with hot (65°C) water. Nitrosoguanidine crystallizes when the solution is cooled to 0°C. The yield is about 50%. 

X = S) is excluded on the basis of the reduction of the corresponding ureas (143) to the known 3-aryl-l-(isopropylideneamino-amidino)ureas (143a R = Ph). In the absence of rearrangement, the condensation products of isocyanates and nitroguanidine may thus be formulated as nitramines (143), and, by analogy, their sulfur analogs as 139.141... 

Nitroguanidine on reduction is converted first into nitroso-... 

Nitroguanidine (NQ) was first prepared by Jousselin in 1887 (Fig. 1.3). However, during WWI and WWII it only found limited use, for example in formulations with AN in grenades for mortars. In more recent days NQ has been used as a component in triple-base propellants together with NC and NG. One advantage of the triple-base propellants is that unlike double-base propellants the muzzle flash is reduced. The introduction of about 50 % of NQ to a propellant composition also results in a reduction of the combustion temperature and consequently reduced erosion and increased lifetime of the gun. NQ can be prepared from dicyandiamide and ammonium nitrate via guanidinium nitrate which is dehydrated with sulfuric acid under the formation of NQ ... 

Reduction of nitroguanidine in a 2M ammonium sulfate solution at a mercury cathode at — l.OV yields nitrosoguanidine, which precipitates addition of nickel ions increases the yield [206]. 

Hydrazine salts have been prepared by the action of hypochlorites on ammonia (1) or urea (2) by the hydrolysis of salts of sulfohydrazimethylene disiilfonic acid (3) by the hydrolysis of triazoacetic acid (4) by the reduction of diazoacetic ester (5) by the reduction of nitroguanidine followed by hydrolysis (6) by the reduction of the nitroso derivatives of hexamethylene tetramine (7) by the reduction of nitrates or nitrites with zinc in neutral solution (8) by the action of sodium bisulfite on hyponitrous acid followed by reduction (9) by the reduction of K2S03N202 (10) by the action of ammonia on dichlorourea (11) by the reduction of nitrosoparaldimin (12) by the action of copper sulfate on ammonia at high temperatures (13) by the reduction of methylene diisonitrosoamine (14) by the hydrolysis of the addition product of diazoacetic ester and fumaric or cinnamic esters (15). 

E. Lieber, G.B.L. Smith. Reduction of Nitroguanidine.VI. Promoter action of platinic chloride on Raney Nickel catalyst J.A.C.S. 58,1417 (1936). 

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