Nitroguanidine preparation

The melting point of 1 -n-propyl-1 -nitroso-3-nitroguanidine, prepared by a similar technique, is reported to be 118°C. 

Another method of nitroguanidine preparation is that of Marqueyrol and Loriette mentioned already [27]. According to Aubertein [61], here nitroguanidine is formed by the following reactions dicyandiamide is heated with 60% sulphuric acid at 150°C to form guanidine sulphate which however is not isolated. Instead, the reaction mixture is treated directly with a 30% excess of anhydrous nitric add at 25°C. Nitroguanidine, m.p. 257°C, is prepared in this manner in a 91 % yield. 

For many years guanidine thiocyanate was the most easily prepared and the most commonly used of the salts of guanidine. Other salts were made from it by metathetical reactions. Nitroguanidine, prepared from the thiocyanate by direct nitratkm with mixed acids, was found to contain traces of sulfur compounds which attacked nitrocellulose and affected the stability of smokeless powder, and this is one of the reasons why nitroguanidine powders did not come into early use. Guanidine thiocyanate is... 

V. Milan and co-workers. The Preparation of High Bulk Density Nitroguanidine, Rpt. 3037, NAVORD, Washington, D.C., 1957. 

The more important methods of preparation of diazomethane include those from nitrosomethylurea, nitrosomcthylurethane, N-nitroso-/3-methylaminoisobutyl methyl ketone, and 1-methyl-l-nitroso-3-nitroguanidine. ... 

JPR269>. 1,3,5-TriaIIyl-hexahydro-l,3,5-triazine has been used in the preparation of a C-4 unsubstituted azetidinone which is the starting material for the synthesis of penems and cephams <00S289>. A novel method for the preparation of AfW-disubstituted-Af"-nitroguanidines via 2-nitroimino-hexahydro-1,3,5-triazine derivatives has been studied <00TL7187>. 

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... 

The facile hydrolysis of A, A -dinitro-2-imidazolidone to ethylenedinitramine (EDNA) shows that A, A -dinitroureas can be useful precursors to linear dinitramines. Cyclic N,N -dinitroureas can be prepared indirectly from nitroguanidine. Nitroguanidine is found to... 

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]. 

The following substances were prepared studied by McKay Wright (Ref 1) starting with the reaction of nitroguanidine with ethylene-diamine to give 2-nitramino- A 2-imidazoline ( A2 is used to indicate that a double bond is attached at position 2) ... 

It was observed that the nitroso-nitroguanidines may cause skin irritation. The higher alkylnitrosonitroguanidines are particularly noxious. The preparation of l-benzyl-l-nitroso-3-nitroguanidine is typical of the techniques used. 

Diazomethane has been prepared by the action of base on nitrosomethylurea,2 nitrosomethyluretbane,6 N-nitroso-/3-meth-ylaminoisobutyl methyl ketone,6 / -tolylsulfonylmethylnitros-amide,8 and N-nitroso-N-methyl-N -nitroguanidine.7... 

This method is commonly applied to the nitration of primary amines (3) and in particular the preparation of nitroguanidine, nitrourea etc., as well as in the nitration of secondary amines (4) ... 

Jousselin [26] prepared nitroguanidine by the action of anhydrous nitric acid or sulphuric acid on guanidine nitrate. The preparation of this substance by the action of sulphuric acid has been developed as an industrial method for the production of nitroguanidine. The method described by Marqueyrol and Loriette [27] follows somewhat different principles. It consists in acting with anhydrous nitric acid on guanidine sulphate which, in turn, is obtained on treating dicyandiamide with sulphuric acid. 

A freshly prepared solution of nitroguanidine in sulphuric acid contains no free nitric acid, but in the presence of substances which are readily nitrated it behaves as if this were so, e.g. the solution nitrates phenol, acetanilide and cinnamic acid and in the presence of mercury reacts in a nitrometer with the evolution of nitric oxide in the same way as nitric acid. Hence in certain cases a solution of nitroguanidine in sulphuric acid may be utilized as a nitrating mixture. 

Bourjol [59] reviewed various methods of preparing nitroguanidine from guanidine nitrate and sulphuric acid, and also carried out extensive experiments to find the most convenient laboratory method of carrying out the reaction. 

In the case of nitroguanidine, a hot aqueous solution was introduced into cold methanol. Still finer and more uniform crystals were prepared by introducing a cold solution in n-butanol into carbon tetrachloride. The results are given in Table 7. 

Nitrourea, like nitroguanidine, is prepared by the action of sulphuric acid on urea nitrate. It was recommended as an explosive by Badische Anilin und Soda-Fabrik in 1915 [62] but without success, as it was not sufficiently stable. In the presence of water it decomposes at a little above 60°C with the evolution of nitrous oxide. 

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%. 

The explosive properties of the potassium salt of nitrocyanamide first attracted McKay s [37] attention. He separated this potassium salt as a by-product from the preparation of aliphatic diazo compounds by the hydrolysis of N-alkyl-N-nitroso-N -nitroguanidines with an aqueous solution of sodium hydroxide at temperatures from 0°C to room temperature ... 

Diazohydrocarbons. 1-Substituted-l-nirroso-3-nitroguanidines when treated with aq KOH gave diazohydrocarbons, McKay et al (Ref) used this method to prepare Diazomethane, Diazoethane, Diazo-n-propane and other Diazocompds. See Ref 2 for their decompn s Cud re s... 

This filtrate on evaporation to dryness and baking at 100 0 leaves a residue of 650 g., which is suitable for the preparation of nitroguanidine (p. 68). 

Nitroguanidine may be prepared by the nitration of guanidine salts by means of nitric acid,1 or by the action of concentrated sulfuric acid upon guanidine nitrate.2 The nitration of guanidine thiocyanate yields a product which retains a small proportion of sulfur compounds, and Lhe nitration of the sulfate requires vigorous treatment and gives poor yields. The present procedure, which yields the alpha form,3 is simple and economical, and furnishes a good yield. 

Guanidine nitrate is of interest to us both as an explosive itself and a component of explosive mixtures, and as an intermediate in the preparation of nitroguanidine. All other salts of guanidine require strong mixed acid to convert them to nitroguanidine, but the nitrate is converted by dissolving it in concentrated sulfuric acid and pouring the solution into water. 

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