Yorty2040
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Nitration of 2-cyanoguanidine
Calcium cyanamide is a widely available agricultural chemical in the EU and China. If you're in North America, it is easy to make via roasting calcium
cyanurate, which can be made by mixing aqueous cyanuric acid with aqueous calcium chloride and filtering and drying the precipitate.
Hydrolyzing calcium cyanamide produces cyanamide, which dimerizes in alkali to 2-cyanoguanidine (AKA dicyandiamide).
This paper states that dicyandiamide can be nitrated to 1-amidino-3-nitrourea by mixed acid, but doesn't say under what conditions. Apparently the
nitrile nitrogen is converted to a nitramine, while the nitrile carbon becomes a carbonyl, but by what mechanism I don't know.
Guidechem.com gives the title of a synthesis reference for 1-amidino-3-NU:
Thiele; Uhlfelder Justus Liebigs Annalen der Chemie, 1898 , vol. 303, p. 108
But I can't find it anywhere, as the name of the journal has probably changed several times over the last century and a quarter, and translation
software has a hard time with text that's in a scanned image.
I'm interested in this substance, as it might make for an interesting ligand in a metal perchlorate complex, but I'm also wondering if sufficiently
vigorous conditions (converting the cyanoguanidine to its nitrate salt ahead of time and using an excess of anhydrous acids) might add more than one
nitro group to the molecule. Of course, the dinitramine or trinitramine might be vulnerable to hydrolysis, lowering yield and making extraction from
the liqueur difficult.
Does anyone have any knowledge regarding the nitration of cyanoguanidine?
[Edited on 29-4-2024 by Yorty2040]
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underground
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Cyanamide is produced from cyanate by heating it to 750-800 C. Cyanate is produced from urea and CaOH/CaCo3. Do some research before you post your
ideas.
http://www.sciencemadness.org/talk/viewthread.php?tid=14342
If you have access to cyanamide so easily then make some hydrazine sulphate from urea and bleach to produce aminoguanidine. The go to amino
nitroguanidine.
[Edited on 29-4-2024 by underground]
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EF2000
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Quote: Originally posted by Yorty2040  |
Guidechem.com gives the title of a synthesis reference for 1-amidino-3-NU:
Thiele; Uhlfelder Justus Liebigs Annalen der Chemie, 1898 , vol. 303, p. 108
But I can't find it anywhere, as the name of the journal has probably changed several times over the last century and a quarter, and translation
software has a hard time with text that's in a scanned image.
[Edited on 29-4-2024 by Yorty2040] |
It appears that you haven't searched well. Justus Liebigs Annalen der Chemie (currently EurJOC) are available on wiley.com. And full pdfs are
available on zenodo.org, like that: https://zenodo.org/records/2345655. With (almost) decent OCR (OCR has some problems with ümläüts and italics though).
"Denselben" is not an author, it means "the same", because preceding paper, ending on page 107, is also by Thiele and Uhlfelder.
Attachment: article.pdf (308kB)
This file has been downloaded 23 times
Wroom wroom
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Yorty2040
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The thermal decomposition of urea produces cyanuric acid. There's no reason I can see that calcium cyanurate couldn't work, though you have a point
that it might be a bit cheaper to just use urea and quicklime.
[Edited on 30-4-2024 by Yorty2040]
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Yorty2040
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"25 g of dicyandiamide are added in small portions to a mixture of 40 cc of azeotropic nitric acid (specific weight 1.4) and 100 cc of concentrated
sulfuric acid, which is in a cold mixture, while stirring constantly. When all the dicyandiamide has been added, let it stand for a while, pour it
onto ice and vacuum filter the nitrodicyandiamidine, which precipitates out as a white powder. To clean it, it is dissolved in diluted potassium
hydroxide solution in the cold and precipitated again using carbonic acid. Small quantities can still be obtained from the mother liquor in the form
of the mercury salt using nitrate salt of mercury oxide. The yield is approximately 95% of theory."
Fairly straightforward procedure, though they don't specify the temperature. I'd say keeping it below 5ºC would be prudent, as would skipping the
mercury salt portion.
[Edited on 30-4-2024 by Yorty2040]
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Hey Buddy
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Nitration of cyanoguanidine will give guanylurea, or the nitrate typically, analogous perchlorate with perchloric acid. You can also prepare
biguanides from it with amines by various methods, direct fusion, alcohol amine reflux, or copper catalyst. Biguanides are often compared to
guanylurea, but they are quite different in terms of cyclic products and behavior. Cyanoguanidine can also be cyclized to guanazole or
guanazoguanazole. Im not sure about nitrous acid effect directly on cyanoguanadine, I would imagine a few different products could be prepared from
various acid and basic mediums with HNO2. Possibly energetic products from oxalic or formic acids. it's somewhat lesser explored in terms of
guanidines in energetic materials. This is currently the area Im playing around in.
[Edited on 3-5-2024 by Hey Buddy]
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Hey Buddy
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| Quote: Originally posted by Hey Buddy | Nitration of cyanoguanidine will give guanylurea, or the nitrate typically, analogous perchlorate with perchloric acid. You can also prepare
biguanides from it with amines by various methods, direct fusion, alcohol amine reflux, or copper catalyst. Biguanides are often compared to
guanylurea, but they are quite different in terms of cyclic products and behavior. Cyanoguanidine can also be cyclized to guanazole or
guanazoguanazole. Im not sure about nitrous acid effect directly on cyanoguanadine, I would imagine a few different products could be prepared from
various acid and basic mediums with HNO2. Possibly energetic products from oxalic or formic acids. it's somewhat lesser explored in terms of
guanidines in energetic materials. This is currently the area Im playing around in.
[Edited on 3-5-2024 by Hey Buddy] |
In fact, could anyone be so kind to hypothesize on likely product from nitrosation of cyanoguanidine?
Possible variation between acetic acid HNO2 functionality versus HCl? Maybe something like what is seen with multiple nitrosation products of
aminoguanidine?
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Boffis
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I have tried nitrating dicyandiamide (=cyanoguanidine) and found that if it is possible, it is very difficult. I first tried a method similar to
guanidine, converted the dicyandiamide into its nitrate salt and then treating it with ice-cold conc sulphuric acid. The problem is that dicyandiamide
is a weaker base than guanidine and the nitrate salt hydrolyses when you try to recrystallise it. When added to conc. sulphuric acid at 0 C the crude
nitrate generated much gas (colourless) then a strong exothermic reaction kicks in and much brown NO2 is evolved with much foaming and the reaction is
very diffiult to control even in small quantities (http://www.sciencemadness.org/talk/viewthread.php?tid=149987...).
I got similar results with stoichiometric amounts of dicyandiamide and 70% nitric acid in three times its volume on ice-cold conc. sulphuric acid. The
presence of traces of lower nitrogen oxides appears to be highly delaterious. So If you are going to try this I would recommend using nitric acid
purged with air and treated with sulphamic acid or similar to remove the lower N oxides.
As for nitrous acid, given my observtions above, I think that it will de-aminate the guanidine as it does guanidine resulting, ultimately in complete
decomposition of the ureide. That said I have studied the action of nitrous acid on guanidine (and posted my extensive results on SM; in the
5-aminotetrazole thread) and the reaction is very susceptible to conditions and the outcome is always a complex mixture of ammonium salts, urea,
nitrosoguanidine, nitroguanidine, guanylurea salt etc.
Nitric acid of less than 50% rapidly converts dicyandiamide to guanylurea nitrate as Hey Buddy correctly states and I have done a few experiments into
this area too (and I think I have posted the result on SM, if not I can do so). The yield is usually very good. The resulting guanylurea nitrate may
be turned into the nitroguanylurea by adding to ice cold conc. sulphuric acid in the same ay as guanidine is nitrate. I have posted information on
this reaction on SM before because there are three possible nitro compound but the evidence is that only one forms (http://www.sciencemadness.org/talk/viewthread.php?tid=80371#...).
If you do try this nitration please keep us informed as I would be very interested.
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EF2000
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| Quote: Originally posted by Boffis |
Nitric acid of less than 50% rapidly converts dicyandiamide to guanylurea nitrate as Hey Buddy correctly states and I have done a few experiments into
this area too (and I think I have posted the result on SM, if not I can do so). The yield is usually very good. The resulting guanylurea nitrate may
be turned into the nitroguanylurea by adding to ice cold conc. sulphuric acid in the same ay as guanidine is nitrate. I have posted information on
this reaction on SM before because there are three possible nitro compound but the evidence is that only one forms (http://www.sciencemadness.org/talk/viewthread.php?tid=80371#...).
If you do try this nitration please keep us informed as I would be very interested. |
It works with higher concentration of nitric acid, if it is added dropwise to solution of dicyandiamide.
Famous Thomas Klapötke got 93% yield with 65% acid: The preparation and characterization of guanylurea nitrate and perchlorate salts
Attachment: The preparation and characterization of guanylurea nitrate and perchlorate salts (214kB)
This file has been downloaded 2 times
Also of interest is that paper by the same Klapötke about a lot of different salts of guanylurea: Low Energy Monopropellants Based on the Guanylurea Cation.
Specific impulse of guanylurea nitrate is the same as for guanidine nitrate: 177 s.
Attachment: Low Energy Monopropellants Based on the Guanylurea Cation.pdf (804kB)
This file has been downloaded 0 times
Also, Ernst-Christian Koch in his review article about nitroguanidine includes a section "Nitration of Dicyandiamide". He references German patent DE 958833 by J. Mayer.
Herr Mayer reacts ammonium nitrate and excess of nitric acid to obtain ammonium trinitrate, then reacts it with dicyandiamide and nitric acid.
Reaction is exothermic. After cooling, reaction mixture is neutralised with ammonia water and nitroguanidine precipitates.
From 12 grams of dicyandiamide 10.2 grams of nitroguanidine are obtained. About 68% yield. And AN from neutralisation can be recycled to ammonium
trinitrate.
Koch's article:Insensitive High Explosives: III. Nitroguanidine – Synthesis – Structure – Spectroscopy – Sensitiveness. Relevant section is 4.2.2 on page
272 (page 6 in attached pdf).
Attachment: Insensitive High Explosives III Nitroguanidine Synthesis Structure .pdf (3.8MB)
This file has been downloaded 2 times
Wroom wroom
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