Org. Synth. 1927, 7, 68
DOI: 10.15227/orgsyn.007.0068
NITROGUANIDINE
[Guanidine, nitro-]
Submitted by Tenney L. Davis
Checked by H. T. Clarke and Ross Phillips.
1. Procedure
To
500 cc. (Note 1) of concentrated sulfuric acid (sp. gr. 1.84), previously cooled in a freezing mixture, is added, in small portions and with hand stirring,
560 g. of crude (Note 2) guanidine nitrate (obtained from 210 g. of dicyanodiamide as described on p. 302). The temperature is not allowed to rise above 20° during the addition. When all has been added, the milky mixture is allowed to stand at room temperature with occasional stirring until it is homogeneous and free from crystals
(Note 3). It is then poured with stirring into 6 l. of a mixture of cracked ice and water. The precipitated
nitroguanidine is filtered, washed free from acid, and recrystallized from the least possible amount (4–5 l.) of boiling water
(Note 4). The yield
(Note 5) is
380–390 g. (
73–75 per cent of the theoretical amount, based on the
dicyanodiamide used). The product melts with decomposition at about
232° (Note 6).
2. Notes
1.
It has been found in checking that the use of 800 cc. of acid, though not necessary, gives a much less viscous solution, which becomes homogeneous more rapidly.
2.
This contains
ammonium nitrate, which, however, does not interfere with the reaction.
3.
The mixture has to stand fifteen to twenty hours before solution is complete.
4.
The solution should be allowed to cool slowly, preferably overnight, when the
nitroguanidine separates in long needles which resemble sublimed
phthalic anhydride. The mother liquor contains only 3–4 g. per liter, and may be discarded.
5.
In checking, yields amounting to
85–90 per cent of the theoretical quantity were obtained from pure
guanidine nitrate.
6.
Melting points varying between
220° and
250° have been obtained on the same sample, according to the rate of heating.
3. Discussion
Nitroguanidine can be prepared by the nitration of guanidine salts by means of
nitric acid,
1 or by the action of concentrated
sulfuric acid, or fuming
nitric acid upon
guanidine nitrate.
2 The nitration of
guanidine thiocyanate yields a product which retains a small proportion of sulfur compounds, and the nitration of the sulfate requires vigorous treatment and gives poor yields. The procedure described, which yields the
alpha form,
3 is simple and economical, and furnishes a good yield. A detailed study of the preparation from
guanidine nitrate and
sulfuric acid has been published.
4
This preparation is referenced from:
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
dicyanodiamide
sulfuric acid (7664-93-9)
nitric acid (7697-37-2)
phthalic anhydride (85-44-9)
ammonium nitrate
Guanidine nitrate (506-93-4)
Nitroguanidine,
Guanidine, nitro- (556-88-7)
guanidine thiocyanate
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