Sciencemadness Discussion Board

Post from Mr Anonymous and my reply to it!

PHILOU Zrealone - 24-3-2003 at 09:40

I received 24 identical POSTs from: Mr Anonymous!
:mad: :mad: :mad: :mad: :mad: :mad:
It is absolutely no fun to open each and see what's in it then errase seing it is the same as previous as a plus they are stil arriving on my mail box (I hope it will not reach 1000 messages)
:( :( ;) ;) :( :( ;) ;)
I understand you want to be anonymous but stil don't send me that much mails!
And please don't reply to me to tell you are sorry (I don't need 30 mails of excuses ;) :P
To prove you I opened all here are the starting addresses:

cripto@ecn.org

Anonymous nobody@remailer.privacy.at

Anonymous Sender anonymous@remailer.metacolo.com

Tarapia Tapioco comesefosse@ntani.firenze.linux.it

Anonymous nobody@nox.lemuria.org

Anonymous nobody@cryptofortress.com

Anonymous via the Cypherpunks Tonga Remailer nobody@cypherpunks.to

A.Melon juicy@melontraffickers.com

Skulking Rogue anon@cheshire.dyndns.org

Nomen Nescio nobody@dizum.com

anonimo arancio nobody@arancio.net

Frog FrogRemailer@bigfoot.com

Tarapia Tapioco comesefosse@ntani.firenze.linux.it

Nomen Nescio nobody@dizum.com

Anonymous nobody@remailer.privacy.at

Anonymous cripto@ecn.org

Anonymous Sender anonymous@remailer.metacolo.com

Anonymous nobody@paranoici.org

Anonymous nobody@cryptofortress.com

Anonymous nobody@cryptofortress.com

Anonymous nobody@paranoici.org

anonimo arancio nobody@arancio.net

Hermes Remailer remailer@eocto.net

Nomen Nescio nobody@dizum.com

This proves a schizophrenic paranoia :) ;) :P :D :D :D ;) ;) :)

Objet :azo-clathrate stoichiometry
>Philou , double check the stoichiometry for the 4/12 azo-clathrate .
-OK but please don't overflow my personnal mail!Here we have U2U message ability, please try to use it!

>sample compound analysis
>
> 6.6345 grams lead picrate
> 2.4120 grams lead hydroxide
> 3.3120 grams lead nitrate
>11.6492 grams lead azide
>
>total 24.0077 grams
-Yes possible I simply calculated the amount of Pb picrate, Pb azide and take those out of the initial Pb(NO3)2 weight! It didn't occured to me that being in slight NaOH excess some Pb(OH)2 might form and reduces the amount of Pb(NO3)2! Anyway, 6,62g; 11,65g are in agreement with what I found!

>A simple mixture will definitely not exhibit the same properties , and will not stabilize the lead >azide .
-Yep; but it should display some of the properties of the complex!

>Alternately , long stirring of of a hot aqueous suspension of the separate ingredients, with lead >nitrate in very slight excess of theory , may possibly result in a gradual formation
>of the clathrate complex which slowly develops and crystallizes out as the least soluble product >of the reaction . It reminds me of the process which slowly forms complex mineral
>deposits which crystallize slowly in hot springs or geological formations , slow but sure .
-Indeed all unsolubles are in equilibrium and display stil little solubilities so they will solubilise in favor of the formation of the less soluble of all (the complex)!

>On another topic , I speculated it may be possible to form a "nitroaminourea" and a series of >heavy metallic salts by a similar >reaction as is known to form nitroaminoguanidine .
>Please share anything you may know or what ideas you may have on this possibility of reacting >nitrourea with hydrazine .
-I already answered this today on the madscience forum in energetic materials!
Anyway: I suspect to make it from nitrourea will be very difficult owing to the poor thermal stability of the MNU!
But assuming urea nitrate is more stable; one can think to two possible ways!
1°) UN + NH2-NH3OH -100°C-> NH2-CO-NH-NH2.HNO3 + NH3(g)+ H2O
Care must be taken with semicarbazide nitrate since it must be quite heat sensitive (looking at NH4NO3 vs NH2-CO-NH3NO3 you may feel that NH2-NH3NO3 vs NH2-CO-NH-NH3NO3 will have the same tendency!)
2°)Semicarbazide + HNO3 --> NH2-CO-NH-NH2.HNO3

Finally the carbazide nitrate may be dehydrated with H2SO4 like guanidine nitrate, urea nitrate to form a nitrocompound!
Now the question is where is the nitro?
O2N-NH-CO-NH-NH2 or NH2-CO-N(NO2)-NH2 or NH2-CO-NH-NH-NO2?

>I presently am working on an experiment which appears to be successful, to form a sodium >methoxide solution in methanol by way of aluminum methoxide .
>Aluminum is amalgamated with mercuric chloride in methanol to form the methoxide of >aluminum , and then the aluminum methoxide suspension is reacted with two moles of NaOH!
-Aluminium methoxyde is a strong base indeed; why do you want to convert it to sodium methoxyde?An alternative way to make Al methoxyde is by refluxing anhydrous methanol with Al powder with dry NaOH!Azeotropic water/methanol will dry the stuff!
It works better with ethanol!

>to form sodium aluminate which precipitates , and a residual solution of sodium methoxide in >anhydrous methanol . This should be an ideal reagent for producing anhydrous hydrazine.
-You stil need the amine to make azide!

>in basified methanol for reaction with isopropyl nitrite to produce sodium azide . I may write >up an optimized lab scale synthesis for sodium azide , after my experiments are completed .
-The simple process needs hydrazine or hydrazinium salt or hydrazine derivative (semicarbazide); an alkyle nitrite like butyl nitrite and a solution of NaOH (base) all reacted together at mild heat under reflux! (Isopropyl nitrite has a too low boiling point to be used)!

No need of anhydrous hydrazine nor of stronger base than NaOH!!!
:cool::cool::cool::cool::cool:

an anonymous apology

Polverone - 24-3-2003 at 14:40

Quote:

From: Anonymous
To: (my e-mail address)
Subject: remailer malfunction mailbombed PHILOU

I swear I did not do that mailbomb crap to Philou, not on purpose anyway. I got a server error instead of a "message sent confirmation" so I resent the message, and apparently the remailer server looped like broken record, resending the message again and again. Apologies for causing any problem. I had entered the option to make two attempts to send the message, not two hundred.

Regarding sodium azide, I have synthesized it successfully at least four different ways, from different solvents at varying degrees of hydration for the hydrazine in basified alcohol, and using different organic nitrites. Comparing the yields has shown that the less moisture present, the better the yield. Hydrazine hydrate is produced by neutralizing hydrazine sulfate with sodium hydroxide and a minimal amount of water. The neutralization produces sufficient water to create a warm slurry of sodium sulfate in aqueous hydrazine hydrate. The aqueous hydrazine hydrate can be taken up in methanol, but considerable water is present from the neutralization, and the resulting methanolic solution of hydrazine can be improved. Hydrazine hydrate taken up into methanolic sodium methoxide will result in an anhydrous methanolic solution of hydrazine, sodium hydroxide, and any unhydrolysed sodium methoxide. On mixing with an organic nitrite, the mixture will heat up and precipitate sodium azide.

The 24 message copies sent to Philou were indeed excessive, but even in ordinary messages sent from Mr. Anonymous I have usually received 5-6 or even more copies of the same text, all sent from slightly different addresses. I'm not sure why this is so.

PHILOU Zrealone - 24-3-2003 at 16:20

Here follows another post of Mr Anonymous!
It seems the problem of mail overflow has reduced, I also (as Polaverone) have 5 to 6 posts from various origins- maybe it is a way to mislead eventual tracking?
I understand better your concern about moisture! But stil I'm sure butanol/butanol nitrite/hydrazine and NaOH solution are a good alternative!
I can line out some troubles with your method!

>Even methyl nitrite works when bubbled through the basified methanolic hydrazine
>solution , using a gas dispersion tube , and a slightly pressurized system .
-Indeed all nitrites works but some very volatile nitrites are fire and explosion hazards! (MeONO (g), CH3-CH2ONO(bp=12°C))

>However three fourths of the methyl nitrite blows right through unreacted , so a
>higher boiling point organic nitrite is preferred . Isopropyl nitrite can be
-Isopropyl nitrite is stil very volatile (bp arround 25°C)

>introduced as either vapor or liquid, and a cold reflux condenser will largely return the
>unreacted nitrite to the reaction . n-butanol is good for butyl nitrite but
>difficult to find over the counter , so a glycol or glycerol nitrite may be better
-Yes harder to find; glycerol nitrite is OK (bp is high and usually you get mono or diester but isolation is hard)

>still, will have to check the boiling point data to be sure. And no, anhydrous conditions
>are not strictly required , but the yields do improve for small scale synthesis when
>there is anhydrous or nearly anhydrous hydrazine in basified methanol . Methanol
-Here is what annoys me most:
Methanol and HNO2 forms readily MeONO via a fast equilibrium:
CH3OH + HNO2 <--> CH3ONO(g) + H2O
Methyl nitrite goes out of the system very fast and drives the reaction to the right side!
Then transesterification will be as fast in you case:
(CH3)2CH-ONO + CH3OH --> (CH3)2CH-OH + CH3ONO(g)
Creating a big loss of nitrite and a serious hazard risk!

>is the best solvent alcohol for the azide formation from hydrazine, probably
>because methanol is the best solvent alcohol for sodium hydroxide and keeps the
-Hydrazine is soluble in many alcools, so does HN3; but NaN3 is much less soluble in higher alcools! NaOH is soluble enough in alcohols to C6 to be used with n propyl nitrite in n propanol and with n butyl nitrite/butanol!

>reaction mixture volume small, enabling greater concentration of reactants in
>solution. Regarding the Aluminum alkoxide being sacrificially converted to sodium
>methoxide, the reason becomes clear if the desired product is sodium azide , NOT aluminum
>azide .
-Yes dehydrating agent!
Why not simply dehydrate ethanol with CaO and then boil over Ethanol/water azeotrope from the refluxing mix of that anhydrous ethanol with dry NaOH??? If water is your concern you may use KOH insted because KN3 is much less soluble than NaN3!!!!
Anhydrous NH2-NH2 corrodes glassware; so does Na alkoxydes and NaOH conc!

>Sorry about the remailer malfunction,it was not my intention to mailbomb you .
>I would/should never treat a promising apprentice student of stoichiometry so poorly :-)
-Sorry to look dumb but I don't understand this last one :-?

>Please edit the azo-clathrate post where you accidentally attempted to impeach my
>experimental quantitative yield data with bad math . Thank You .
-It wasn't bad maths because we had the same numbers!
:):D;):P:cool:

Polverone - 28-3-2003 at 12:28

Quote:

From: Anonymous
To: (my e-mail address)
Subject: relevant information

Here are some points of information which are relevant to the experimental syntheses of sodium azide which I am investigating.

1. The boiling point of isopropyl nitrite is 40-45 degrees centigrade (745 to 762 mm Hg), not 25 degrees as Philou Zrealone misreported :-) typo?

2. The nitrite ester exchange (transesterfication) from reaction of the isopropyl nitrite, glycol dinitrite, or other organic nitrites in contacting the methanol, could actually be a desirable reaction occurring in solution to produce a highly subdivided, soluble and reactive form of "nascent methyl nitrite". The nascent methyl nitrite forming in situ would then react much more readily with the hydrazine, than would be the case for methyl nitrite which is introduced as larger bubbles from a gas dispersion tube. The strategy of creating nascent methyl nitrite in situ is a valid technique for avoiding the losses which would otherwise be much greater when using physical methods for introducing the methyl nitrite into solution. It is also possible that the intermolecular forces which are present for the transfer of the ester, may cause destabilization of the parent ester, which then reacts preferentially with the hydrazine before any transfer of the ester occurs. It could also be possible that the reaction with hydrazine is more favored irregardles of the potential for transesterfication. These potentials are related to variables of concentration and temperature, but one thing remains certain, that in any case the desired nitrosation of the hydrazine should still occur unimpeded, regardless of which organic nitrite ultimately becomes the nitrosation agent.

The concerns over explosive vapors and proper venting of the reaction to a remote area will apply regardless of which nitrite is used for the nitrosation. I use a vent tube from the top of a reflux condenser and bubble any escaping vapors into a jug of water containing a little urea or ammonia. The jug is placed thirty meters away, to function as a scrubber for any nitrous vapors which escape. In comparison with other organic nitrites, isopropyl nitrite and methyl nitrite both have good stability.

Because of the ease of synthesis and the high boiling point, the ethylene glycol dinitrite (b.p. 98 degrees centigrade) is of particular interest as a nitrosation agent. See US2166698.


3. CaO, KOH, and n-butanol are not common over the counter materials. It is the goal to use only the most common materials as feedstocks, so that the synthesis is attainable without any need for using ordered chemicals.

4. There is no serious attack of borosilicate glassware by the reaction mixture, even in the anhydrous form, when the reactants are dissolved in methanol at the mild temperatures where these reactions occur. The synthesis of methanolic sodium methoxide by use of aluminum amalgam and methanol to first produce aluminum methoxide, then reacted with 2 moles NaOH and filtered, may be an unpublished method. Someone should check the literature to see if the method is novel.

Polverone - 29-3-2003 at 14:14

Quote:
From: Anonymous
To: (my e-mail address)
Subject: azide reaction and safety information

The mildly exothermic nitrosation of hydrazine reactions proceeds fine at only a moderately warm temperature, about 60-65 degrees centigrade. Refluxing is not necessary for the nitrosation reaction itself, and is probably counterproductive due to boiling out of dissolved nitrite which is desired to remain in solution. Towards the end of the nitrosation when the exotherm has subsided and the reaction temperature has been maintained with supplemental heating for a half hour, It is a good safety precaution to increase the heating of the reaction mixture to the boiling point and let it boil gently for three or four minutes with venting and no refluxing. This boiling expells any unreacted residual nitrous fumes from the closed apparatus and carries the nitrous funes away on the stream of methanol vapors, before the system is cooled completely and only then is the nitrosation flask unstoppered and opened to the atmosphere. Mixtures of flammable hot organic vapors like alcohol vapors mixed together with nitrous fumes can auto-oxidize and ignite pyrophorically if suddenly exposed to the air, and the resulting flash ignition and explosion of vapors can destroy the apparatus to the great surprise and distress of the careless chemist. This warning is based upon having learned this from experience, and it was an unnerving and unpleasant experience indeed. Actually it was an entirely different synthesis involving a different nitrosation, not the synthesis of sodium azide. But that experience taught me an unforgettable lesson to NEVER vent a hot nitrosation or nitration apparatus containing any organic vapors. Now there's a good job for Asimo, Honda's mechanical wonder. Just have the robot repair or first aid kit handy, hehehe. Or get Asimo a flak jacket.

The sodium azide precipitates as an adherent film of crystals that sticks to the glass and grows into a soft layer of crystals encrusting the inner walls of the flask. There is an easy way to break free the crystals of sodium azide so that they can be rinsed from the flask with the supernatant methanol having been transferred to a wash bottle. I use a thumb sized block magnet on the outside of the flask to move an oval stirbar across the inner surface and scrape free the sodium azide like scraping frost from a windshield on a cold morning. You see I have now invented the magnetic teflon policeman, and he is the only policeman which I ever want to see near my sodium azide :-). It should go without saying, that working with hydrazine solutions, and even more important with azide containing solutions, that these are manipulations which should be performed only while wearing at least safety glasses and surgical gloves to keep any spattered solution off the skin. Sodium azide is extremely toxic, about half as toxic as sodium cyanide, and it must be treated with due caution.

Mr. Anonymous shares once more

Polverone - 8-4-2003 at 11:27

Quote:
There is a semicarbazide patent which is of interest not only as an alternative method for semicarbazide, but also relates to a better knowledge concerning my theoretical "nitroaminourea". The patent GB790066 is worth a read.

Regarding the theoretical "nitroaminourea" compound which I mentioned in an earlier communication, see GB790066, Example #3. The patent refers to the compound as the "hydrazine salt of nitourea". This appears to be the same compound as what could be called "nitroaminourea". I believe that the patents "hydrazine salt of nitrourea" could be used to form a lead salt analog, differing only slightly from the known lead nitroaminoguanidine, See GB553406, Example 1. My theorectical "lead nitroaminourea" would differ only by having an Oxygen in a double bond to the Carbon, instead of the NH in a double bond to the Carbon, as appears for the lead nitroaminoguanidine compound. It is my guess that the nitroaminourea would be even more acidic and form the lead salt more readily than nitroaminoguanidine. The lead salt of nitroaminourea would very likely have explosive properties similar to lead nitoaminoguanidine.

If anyone has access to PATR, or another comprehensive database, please check to see if my proposed "lead nitroaminourea" primary is already known, or if it is novel.

Regarding the sodium azide synthesis which I have been attempting to refine, I have been thinking more about the aluminum amalgam / sodium methoxide synthesis for producing a dehydration agent. A problem has been recognized concerning the use of sodium methoxide alone as a dehydrating agent. I have been checking the figures for the dehydration of aqueous hydrazine hydrate in methanol and it is evident that to completely dehydrate the solution to anhydrous methanolic hydrazine only by using sodium methoxide will result in an excessive amount of NaOH in the methanolic hydrazine as an undesired by product. A possible better solution is to first use aluminum methoxide directly as a dehydrating agent for the methanolic aqueous hydrazine, to reduce the water content to a residual few per cent, then filter out the insoluble AL O (OH). Each mole of aluminum methoxide should decompose 2 moles of water while releasing 3 moles of methanol, without introducing any soluble hydroxide to the methanolic hydrazine being dehydrated. The resulting very nearly anhydrous methanolic hydrazine, can then be basified with only the desired amount of NaOH and then reacted with ethylene glycol dinitrite, to produce sodium azide. Alternately, to the nearly anhydrous methanolic hydrazine can be added the desired amount of sodium methoxide, to produce a super anhydrous solution of hydrazine in methanol, and then reacted with ethylene glycol dinitrite.

Yesterday I distilled a liter of ethylene glycol from 1200 ml of Peak antifreeze, leaving the residual material which is mostly diethylene glycol, phosphate anticorrosion additive, and dye. In preparation for the synthesis of ethylene glycol dinitrite, I need to calculate the proper amount of water to be present so that the sodium chloride produced as a byproduct of the esterfication remains in solution, at something slightly less than saturation, so it does not settle out with the ethylene glycol dinitrite. The patent US2166698 did not disclose the correct dilutions, so I need to formulate my own numbers for this which willwork.

Microtek - 9-4-2003 at 04:35

I presume that the NaCl would be produced by reaction of HCl gas with NaNO2 ? If this is the case I suggest simply bubbling N2O3 into the aqueous ethylene glycol. N2O3 is easily produced by adding starch to 50-55 % HNO3 and warming. Evolution of the gas is steady and controllable and the nitrosation action is good.

PHILOU Zrealone - 10-4-2003 at 05:50

I haven't acces to the related patents; so I don't know synthesis pathway but from what I know:
Guanidine nitrate is (NH2)2C=NH.HNO3
Aminoguanidine nitrate is (NH2-NH)(NH2)C=NH.HNO3
Diaminoguanidine nitrate is (NH2-NH)2C=NH.HNO3
Triaminoguanidine nitrate is (NH2-NH)2C=NH-NH2.HNO3

The related nitroguanidine, aminonitroguanidine, diaminonitroguanidine and triaminonitroguanidine should then be:
(NH2)2C=N-NO2
(NH2-NH)(NH2)C=N-NO2
(NH2-NH)2C=N-NO2
(NH2-NH)2C=N-NH-NO2 (very unprobable)

On a parallalism with urea:
ureanitrate:
NH2-CO-NH2.HNO3 --> NH2-CO-NH-NO2
(What provides NH2-CO-NNa-NO2 and related primaries!)
aminoureanitrate
NH2-CO-NH-NH2.HNO3 (here the H+ is on the NH2 of the hydrazine part!)
--> (i doubt it is possible) NH2-CO-NH-NH-NO2
diaminoureanitrate
NH2-NH-CO-NH-NH2.HNO3 (maybe 2 HNO3 because the two terminal NH2 are very distant from each other?) --> very unlikely:
NH2-NH-CO-NH-NH-NO2 and O2N-NH-NH-CO-NH-NH-NO2

So there is a real problem with the stated nitroaminourea:
First:
hydrazinium salt of nitrourea is NH2-NH3-N(NO2)-CO-NH2 or NH2-NH2.HN(NO2)-CO-NH2
and is not NH2-NH-CO-NH-NO2 or O2N-NH-NH-CO-NH2!

Secondly:
2NH2-NH2.HN(NO2)-CO-NH2 + Pb(2+) -->
Pb(N(NO2)-CO-NH2)2 + NH2-NH3(+)
You only make the Pb salt of nitrourea!

thirdly:
DNU (dinitrourea) has already been investigated and provides stable K and NH4 salts (mono and disalts)!
O2N-NH-CO-NH-NO2 + KOH --> O2N-NK-CO-NH-NO2 + H2O
O2N-NK-CO-NH-NO2 + KOH --> O2N-NK-CO-NK-NO2 + H2O
From those many primaries heavy metal salts have been prepared and studied!
No doubt the study has been done for the known for ages stabler MNU (Mononitrourea)!

:mad::o:(:o:mad:

continued

Polverone - 11-4-2003 at 10:48

Quote:
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.