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| PHILOU, You are quite correct that the new compound of patent GB790066 is slightly different from my proposed "nitroaminourea" or "nitrosemicarbazide", by having an NH3 which would not be present in my proposed theoretical compound. It was my hope that someone would see the extra NH3 included in the patents "hydrazine salt of nitrourea". This discrepancy is worthy of mention, and I also recognize the potentially troublesome extra NH3. The new compound of the patent differs because there is no NH3 evolved from the combining hydrazine and nitrourea, so the mechanism and product is not exactly parallel to the known reaction between hydrazine and nitroguanidine, which does evolve NH3 as a reaction by product. However, I would speculate that this same evolution of NH3 may also occur for hydrazine and nitrourea if the reactants were brought into contact in an alkaline system, under conditions parallel to those used for hydrazine and nitroguanidine. I believe the buffering of the reaction may be a factor in determining which product occurs. It may also be possible to produce a "hydrazine salt of nitroguanidine" where no evolution of NH3 occurs, in a system where the pH does not favor the formation of nitroaminoguanidine. Alternately, a gentle alkaline hydrolysis (for example using sodium acetate or bicarbonate) of the "hydrazine salt of nitrourea", may result in an evolution of ammonia, so that the first decomposition product is my theoretical "nitroaminourea". This would immediately combine with the basifying agent responsible for the alkaline condition, resulting in a sodium salt with that substance. Treatment with dilute HCl would then form the free "nitroaminourea." Sooner or later I will do an experiment to determine directly if this theory has any validity or not. You may have already mentioned that semicarbazide nitrate may possibly be subjected to dehydration by H2SO4, in a manner parallel to to the production of nitrourea and nitroguanidine, as a possible direct method for "nitroaminourea" (which is synonymous with "nitrosemicarbazide" . Below is more like what I have been writing
concerning the theoretical compound, expressed in terms of a simplified equation, for the "hydrazine salt of nitrourea" intermediate.
Indeed, in a properly buffered system, is it "impossible" for this reaction to proceed directly from the "hydrazine salt of
nitrourea?" I do not know, because I have not done the experiments.2 (NH2-NH2-HN-NO2--CO-NH2) + Pb(OH)2 ------> Pb(OON-N-CO-NH-NH2) 2 + 2 HOH + 2 NH3 Please indulge my occasional ramblings concerning theoretical reactions. Such possible reactions are of interest to me because lead nitroaminoguanidine is known to have activity in forming complexes with other primaries, and if lead nitroaminourea exists, then it would have interest also in many experiments for energetic materials which could very likely be novel compositions of matter. In your earlier post, you mentione something about which I am curious to know more. >On a parallalism with urea: >ureanitrate: >NH2-CO-NH2.HNO3 --> NH2-CO-NH-NO2 >(What provides NH2-CO-NNa-NO2 and related primaries!) >aminoureanitrate Please provide further information and details about NH2-CO-NNa-NO2 and related primaries. Those compounds are entirely unfamiliar to me. Thanks. Regarding the ethylene glycol I distilled from antifreeze, I did a simple atmospheric distillation and after checking the density, was surprised at the amount of water in the distillate. The glycol which was distilled over without any fractionation, has a specific gravity of 1.104, which is only 81. 5 per cent glycol. It is good to know how much glycol is actually in your glycol solutions, so a good chart for reference is handy. At the following link, a printable chart for the density curves for three common glycols is provided. http://www.pprbook.com/page%204-19.pdf BTW, Does anyone know if ethylene glycol forms an azeotrope with water? Obviously to obtain the ethylene glycol in the anhydrous condition which is desirable for the more difficult nitration to a nitrate ester, will require either fractional distillation, or a drying of the distillate over a dessicant like magnesium sulfate. Microtek, The HCl is aqueous, and dilute H2SO4 is an alternative choice. The esterfication of alcohols in cold aqueous systems is straightforward, so I will follow the method of the patent US2166698 closely or with slight modification to suit my own thinking. The suggestion you made for gas phase nitrosation also has validity, but since I have on hand more than forty kilos of NaNO2, then it is much easier for me to follow the classical method for organic nitrites such as described in US2166698 for ethylene glycol dinitrite. It is much easier to handle liquids than gases anyway. Often there are problems getting good reaction efficiencies with gas reactions unless pressure vessels and special methods are used. A principal aim in using the ethylene glycol dinitrite for the nitrosation of hydrazine is to simplify the process and use direct methods involving only solid and low volatility liquid, easily isolated and measured components. My experiment for esterfication of 1 mole of ethylene glycol will be as follows: Dissolve 140 grams NaNO2 in 300 ml distilled H2O, and add 63 grams of ethylene glycol, or an amount of concentrated glycol solution containing 63 grams of pure ethylene glycol. Chill the solution in a freezer, and also chill in a separate container 200 ml of 31.45 per cent HCl. To the well stirred glycol/nitrite solution maintained cold in an ice salt bath, add dropwise the 200 ml HCl at a rate so that the temperature does not exceed 10 degrees centigrade. After the addition is completed, the stirring is discontinued and the supernatant sodium chloride solution is mostly decanted, the residue transferred to a separatory funnel, and the bottom layer of ethylene glycol dinitrite is drawn off. The material should be stored in the freezer until used. The 300 ml of water used in making the glycol/nitrite solution is not necessarily optimum. The least amount of water which will not result in crystallization of the nitrite when the solution is chilled may be somewhat less, or more, depending on how cold is your freezer. A few solubility tests will determine the minimum water required, and then a few added per cent of water added above that amount in any subsequent synthesis, to be confident that the stock solution is concentrated, yet not subject to crystallization on cooling. |