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Discourse  Hexamine
hydrolysis references
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| Author | Topic: Hexamine hydrolysis references |
| KrZ Member |
posted 10-29-1999 12:14 AM
All I've been able to turn up so far are these; Organic Reactions, Vol. 8, 1954 p.197
I'm thinking that SWIM might resolve these problems in the near future in the following way. Follow the ratios from the recipes page, use a non-cooled condensor to vent the HCl and H2O and CO2 coming off away from the boiling water and thus prevent recondensation of the water bath into the flask. Heat heat and more heat until the whole mix looks dry. Cool and add a large volume of warm acetone, filter off the MeAm (removes hexamine). Dissolve the MeAm in warm chloroform, filter from insolubles and cool until recrystalization is complete (removes DiMeAm, TriMeAm, and hexamine). Filter off the MeAm and disolve in boiling n-BuOH (removes NH4Cl) then decant (can't filter, clogs the paper to badly) and recrystalize again. Recover the recrystalized MeAm, wash with cold acetone and weigh to obtain final yield. As far as I can see this would effectively remove everyone of the possible contaminating agents listed as being the reasons for discrediting the reported yields. The long reaction time (Probably about 12 hours) should also give the most complete reaction possible. Tell me what you think. |
| KrZ Member |
posted 10-29-1999 12:19 AM
That chloroform rextalization should actually be a chloroform wash. |
| dr.strangelove Member |
posted 10-29-1999 09:18 AM
KrZ- I have ran this reaction every way imaginable,set-up wise, and the best yields I have achieved were quantitative, (once in a while) or high 90's using the vaccuum version. The reason I dont use it all the time is that I use a water pump, and 8 hours is a long time for that, much less 12 hours. I can achieve a very reproducible, respectable yield using the way advocated by chemhack in his original post. Just reflux that bitch for about 10-12 hours at the range of 104-109c... It'll be yellow, but the clean ups with alcohol is very effective if
done correctly. Also, the corrosive vapors from the exhausting of HCl vapors ate the sides out of my fucking aspirator eventually, but since I have about 23 more, thts OK, too. My verdict: Reflux as long as possible. Keep it >110c. It takes about 11 hours or so, usually, depending on how well you stabilize the shit in the early going... This is still the best way to make it I have ran across. The Hoffman is an amazing pain in the ass. |
| Synthia Junior Member |
posted 10-30-1999 06:44 AM
Dr Strangelove: Have u not tried Sumerian HCL/Hex > MeAM?? Check it out ,and tell me what u think. Synthia |
| ChemHack Member |
posted 10-31-1999 09:01 PM
quote: I believe the good Doctor meant to reflux at LESS than 110c, not greater than 110c. |
| homebrew Junior Member |
posted 11-01-1999 12:30 AM
Sir, Have yoyu seen the method of using 40% methylamine olus equal molar amounts of HCL, combine both items while very cold, then vacumn off the water for excellant yeilds of pure product? |
| KrZ Member |
posted 11-01-1999 12:57 AM
Wouldn't that be nice homebrew. Go be a wiseass elsewhere. |
| K.C.
Nicolaou Member |
posted 11-01-1999 01:34 AM
KrZ - The process of hexamine hydrolysis is fundamentally the same as the formaldehyde/NH4Cl method. If you want refs you're probably going to find more for that rxn. My experience with hexamine hydrolysis is that at the dilution obtained from adding enough H2O to dissolve the hex at room temp and enough muriatic acid to get a slight excess of HCl, the sol'n refluxes at ~105C, making temperature control unnecessary. In my opinion, the vacuum method doesn't give a significant improvement, since the rxn is not reversibe and CO2 isn't very soluble in hot water anyway. Any method that tells you to distill while doing the rxn is bullshit, because you are just distilling off your reducing agents (formaldehyde, formic acid, and their esters and acetals) Also, let the rxn reflux for a long time. I have observed CO2 evolution after as long as 8 hours of refluxing(as seen when the rxn is taken to 10 degrees belom the reflux temp). I am currently trying to tweak the ratio of formaldehyde to ammonium chloride to suppress the formation of dimethylamine and increase overall yield, but that isn't quite ready for posting here. Anyways, you never gave a final answer as to whether mag stirring through a soda keg is do-able. Also, where did you get yours? Stealing is for punks in my opinion, as it might attract unwanted atention. |
| KrZ Member |
posted 11-01-1999 01:46 AM
I bought it fucko (fucko added just in case that stealing remark was for me). DiMeAm is formed when the temperature hits 110C, so if you stir your mix and/or heat it up to 104 very slowly you should be good. What are you adding water to your reaction for anyway? I have seen and read plenty of CHO+NH4Cl ref.'s and what I wanted to see was some little sidenote about Hex. hydrolysis in some ref. somewhere. The french 1895 ref. has a brief description of his attempt to prove the hydrolysis mechanism and in situ MeAm formation. In my not-experience, the easiest way to do an NH4Cl/CHO rxn is simply to set the mix on the water bath, heat to 100C and just let it get heated until it's all boiled down. That's the not-plan for hexamine still, I'm not going to try refluxing or low pressure anything, just a good long ass water bath, as long as it takes. Water bath is simple, I can leave it unattended and it has worked great with the similar reactions. So I'll tell you how that goes when SWIM does it, including acetone, chloroform, and n-BuOH to make sure the % yield is just for pure MeAm. |
| K.C.
Nicolaou Member |
posted 11-01-1999 02:37 AM
Well fine then fucko(no, that was not what I meant, I was just trying to find out WHERE to buy one without walking my lazy ass over to the phonebook, where I'm sure I could find that information myself), The water was added because I am working from fuel tablets and I need to filter the binders. Besides, if you already have experience with formaldehyde/ammonium chloride, why do you need a reference to know that hexamine formation is reversible in acidic water? By the way, how's the MeNO2 reduction going? I think I'll wait and see if you blow yourself up before I try fucking around with that one  . When
SWIM gets done with his/her experiments, I'll see if my method turns out
to be higher yieldingor not. Of course I'll be awfully tempted to just
evaporate all of the water, call everything left methylamine, and claim
100% yields like some other idiots have done.
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| rev
drone Member |
posted 11-01-1999 03:00 AM
Do you want just those that involve hexamine, or will those that start with formadelyde and paraformaldehyde do? ------------------ |
| KrZ Member |
posted 11-01-1999 08:14 AM
Rev drone. All the CHO/NH4Cl references that I saw used the 104 then down to 100 reaction temp.'s, people said hexamine hydrolysis need only be conducted at 100 the whole time. I just wanted to see someone in a journal say the same thing. I was hoping to find the source of the reaction details in the recipes section. So please, some hexamine references. "hexamine formation is reversible in acidic water" |
| K.C.
Nicolaou Member |
posted 11-01-1999 11:31 AM
1. 6 CH2O + 4 NH3 -> 1 C6H12N4(hex) + 6 H2O under nuetral conditions, and 2. 1 C6H12N4 + 6 H2O 4 HCl -> 6 CH2O + 4 NH4Cl in the presence of excess acid. When you add 4 moles HCl to 1 mole of hexamine, it hydrolizes to give 6 moles of formaldehyde and 4 moles of ammonium chloride, which go on to react as usual. The only practical difference in the two reactions is that the starting materials are in a slightly different form, and you have to account for the fact that the hexamine has to be allowed to hydrolyze before the methylamine-forming rxn occurs. |
| ChemHack Member |
posted 11-02-1999 05:26 AM
Entering Sportscaster Mode: Wanna see just how soluable that gas is? Heat that bitch up to 100C without stirring for a few hours so its damn hot but not hot enough to boil or reflux. Now stick a glass rod in there and stir some by hand! Holy Moses! Stand back! Its like rolling a 3-litre soda bottle down a flight of stairs and then opening it! Spew City! Yes ladies and gentlemen! That IS acidic water boiling down there below the oil bath. Somebody call the doctor! ====================== Return to normal voice: |
| Ollie-RSM Member |
posted 11-02-1999 09:49 AM
Soda Kegs: $12 used (sticky) at a homebrew supplier. You can find them on the web for >$30 reconditioned. |
| KrZ Member |
posted 11-02-1999 10:46 AM
I was thinking of using a rotovap arm to spin the flask for faster distillation, but then I decided stirring would be better. And Ollie-RSM you'd better be quite, those soda kegs are far to dangerous for these bees
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| hellman Member |
posted 11-02-1999 07:02 PM
Krz, It's been said LOTS of times, although now I believe you have laid it out for the laymen, Rhodium--snip here----- Methylamine via Hexamine Courtesy of KRZ-Due to the fact that he'll probably not write this up, I'll make it so. -snip: Ever tried making MeAm from hexamine, well... there's been a lot of speculative and informal methods going down, and supposing you want to successfully make this stuff from Easy OTC camping fuel, you might as well have the best information you can get you feverishly clandestine hands on. Prologue: (courtesy KRZ) Hellman |
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