Guanidine-nitric acid

In the commonly used Welland process, calcium cyanamide, made from calcium carbonate, is converted to cyanamide by reaction with carbon dioxide and water. Dicyandiamide is fused with ammonium nitrate to form guanidine nitrate. Dehydration with 96% sulfuric acid gives nitroguanidine which is precipitated by dilution. In the aqueous fusion process, calcium cyanamide is fused with ammonium nitrate ia the presence of some water. The calcium nitrate produced is removed by precipitation with ammonium carbonate or carbon dioxide. The filtrate contains the guanidine nitrate that is recovered by vacuum evaporation and converted to nitroguanidine. Both operations can be mn on a continuous basis (see Cyanamides). In the Marquerol and Loriette process, nitroguanidine is obtained directly ia about 90% yield from dicyandiamide by reaction with sulfuric acid to form guanidine sulfate followed by direct nitration with nitric acid (169—172). 

The strained A-nitroazetidine (36) has been synthesized from the nitration of the hydrochloride salt of the corresponding azetidine (35) with acetic anhydride-nitric acid. The heterocyclic guanidine (38) is synthesized from (37) in a similar way. ... 

Boyer and co-workers" also reported the synthesis of the guanidine tricycle (122), prepared as the tetrahydrochloride salt from the condensation of two equivalents of guanidine with 1,4-diformyl-2,3,5,6-tetrahydroxypiperazine in concentrated hydrochloric acid. Treatment of the tricycle (122) with absolute nitric acid yields thebis-nitrimine (123), whereas the same reaction with nitric acid-acetic anhydride yields HHTDD (117). 

Triamterene Triamterene, 2,4,7-triamino-6-phenylpteridine (21.5.13), is synthesized in by the following scheme. Reacting guanidine with malonodinitrile gives 2,4,6-triaminopyrimi-dine (21.5.11). This undergoes nitrosation by reacting it with nitric acid, which results in the... 

N-(j3-Nitroxyethyl)-N -nitroguanidine or 1-(2-Nitroxyethyl)-3-nitro-guanidine. 02N0.CH2.CH2NH.C( NH)NH.N02 mw 193.13, N 36.26% crysts (from 95% ale), mp 161° (dec), explodes by impact. The compd was prepd by suspending jS-Hydroxyethylnitroguanidine in acetic anhydride and adding dropwise 99% nitric acid at -5° for 10 mins. The compd explodes by impact (Ref 2)... 

Nitroguanidine Guanidine, Sulfuric acid. Nitric acid... 

Ammonium nitrate, Chlorine gas Anhydrous ammonia, Chlorine gas, Water Glycerin, Sulfuric acid, Nitric acid Guanidine, Sulfuric acid, Water... 

OB -13.3% yel crysts, plates (from w), with rapid heating expl at 180 — 184° si sol in cold w insol in ale eth. Prepd by K permanganate oxidation of amino-guanidine nitrate in nitric acid (Ref 2)... 

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. 

Ammonium nitrate is also miscible with fused salts of nitric acid. The composition of the eutectics and the fusion temperatures of mixtures with sodium, potassium, and calcium nitrate are considered in future chapters (Vol. III). Data concerning the properties of mixtures with guanidine nitrate, nitroguanidine, ethylene diamine dinitrate, are also reported in Vol. III. 

Guanidine salts have been prepared by heating ammonium thiocyanate,1 by hydrolysis of dicyanodiamide by acids,2 (whereby one molecule of the guanidine salt is produced), and by the action of ammonium salts on dicyanodiamide,3 from which two molecules of guanidine salt result. The nitrate has been prepared from the thiocyanate by the action of nitric acid.4... 

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. 

Nitric acid and organic and inorganic nitrates, and in general all substances which contain free nitric acid or yield nitric acid when they are treated with concentrated sulfuric acid, are analyzed by means of the nitrometer. The method depends upon the measurement of the volume of the nitric oxide which is produced when concentrated sulfuric acid acts upon the sample in the presence of mercury. It is satisfactory also for the determination of nitro group nitrogen in certain nitroamines, in nitro-guanidine and in tetryl but not in methylnitramine. It is not satisfactory in the presence of mononitro aromatic compounds or of other substances which are nitrated readily by a solution of nitric acid in concentrated sulfuric acid. 

The nitric acid of the original 2 mols of ammonium nitrate is exactly sufficient for the formation of 2 mols of guanidine nitrate. But the intermediate biguanide is a strong diacid base the ammonium nitrate involved in its formation supplies only one equivalent of nitric acid and there is a point during the early part of the process when the biguanide mononitrate tends to attack the unchanged ammonium nitrate and to liberate ammonia from it. For this reason the process works best if a small excess of... 

A good yield of guanidine nitrate is obtained by treating dicyananiide (obtained by heating cyanamide) with a mixture containing 25 per cent, of hydrochloric acid (1 19) and 35 per cent, of nitric acid (l-38), in water. 

N 21-27% orn-red prisms (from ale), mp 197° (dec) sol in acids si sol in cold alkalies insol in w. It was ptepd by treating N,N -Di-p-tolyl-guanidine with nitric acid (dl.5) and avoiding any rise in temp during nitration ( Refs 5 6)... 

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