Sciencemadness Discussion Board - Good way to Methylamine HCl?

Good way to Methylamine HCl?

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Wolfram - 21-12-2003 at 10:56

Suppose I would like to make some mythylamine HCl. First I would put some hexamine in water add hcl reflux for six hours at 105 C on an oilbath. A mix of methylamine and ammoniumchloride would form. If I would add a sultion of NaOH, freebase methylamine would be to expect, right?
Methylamine boils at 48 C so I could destilate over the methylamine and condens it down in hcl to gain methylamine HCl.

[Edited on 21-12-2003 by Wolfram]

[Edited on 21-12-2003 by Wolfram]

fritz - 21-12-2003 at 12:31

Are you shure you will have a mixture of ammonium- AND methylamine-HCl??
I would expect that you have only NH4Cl because in acid solution urotropine will split in ammonia(=ammonium-salt) and formaldehyde.

If your method really works try some other separating method (extracting the methylamine-HCl with absolute EtOH) destillating the mixture with NaOH would also release ammonia. So in the end you´ll be were you started!

If your method fails you may perhaps try this:
In a 500ml flask add 80g (26ml) bromine to 30g acetamide with good cooling add a solution of 50g KOH in 350ml water until the red colour of the bromine deceased and the solution is yellow. This solution you add to a warm (70-75°C) solution of 80g KOH in 150ml water. you maintain warming (ca.15-30min) until the solution is colourless then you distill the methylamine until the condensing liqiud reacts no more alkaline. (collecting the destillate in 100ml 5n HCl) The solution of ammonium- and methylamine-HCl is evaporated to dryness and dried overnight in a vacuum desiccator. It is extracted by boiling with abs. EtOH. The filtrate (solution of methylamine-HCl ) is boiled to a small volume and after cooling the methylamine-HCl precipiates. It is washed with EtOH and dried in a desiccator.

Organikum - 21-12-2003 at 13:01

methylamine boils at - 6°C, but it will not distill over from an aqueous solution same as ammonia wont do.

https://www.rhodium.ws/chemistry

unionised - 21-12-2003 at 13:19

Interesting logical / grammatical point. Technically it is true to say that methylamine won't distill from water in the same way that ammonia won't. It's just that it's a bit misleading. Both will. You can distill both bases to recover them from water.
If you have a saturated solution of methylamine at 12.5 C (where 1154 vols of the gas are soluble) and heat it to 25 C where only 959 vols are soluble, the difference will come out of solution. Those 2 points are the only data I have on the solubillity. I would presume that further heating will drive more of the amine from solution.
I have a vague memory that the standard lab prep of methylamine is the reaction of ammonia and formaldehyde in acid conditions, but I'm not sure.

why not....

Organikum - 21-12-2003 at 13:24

To 1mol hexamine (about 140gram) dissolved in 3 liters dH2O is added over 4 hours 2mol Zn (about 125gram in theory, use at least 150gram) in SMALL portions with strong stirring and so much muriatic acid that the reaction stays slightly acidic all time. Temperature is roomtemperature or below and should STAY so. Cool it so necessary - more water doesnt hurt so icecubes are fine....

Stirr on for at 6 to 12 hours.

Basify with NaOH.

Smell what you wanted to smell poor boy.
Steamdistill directly into some 15% HCl.
Methylamine.HCl - bingo.

Go to Rhodiums page for description of further workup, chloroform is NOT needed if done the described way - the IPA extractions are all whats necessary to get rid of ammoniumchloride. No dimethylamine is formed.

enjoy.
yields: from 85% up to theory

[Edited on 21-12-2003 by Organikum]

fritz - 21-12-2003 at 13:31

I´m sorry but I insist in my explanations!
Why should ammonia/methylamine not boil from water?
You will have a equilibrium: on the one side water and Ammonia/methylamine on the other side hydroxide protonated ammonia/methylamine:

NH3 +H2O <> HN4+ + OH-

MeNH2 + H2O <> MeNH3 + OH-

so if you boil such a mixture ammonia will evaporate and the first equilibrium will be shifted to the left side. (never boiled ammonia-solution??!?)
Why should the same not happen to methylamine? O.k. the base strength of methyl amine is higher than that of ammonia but at room temperature it´s also gaseous so it would evaporate which will led the secon equilibrium also to be shifted to the left side!
The evaporation will also take place in alkaline solution so the OH- ions will shift both equilibria to shift to the left side because OH- is the strongest base in water and so it will deprotonate every base in water. I found this method in a book about organic chemistry ... the only thing I really trust are books. so where would it lead if we can´t trust our tresuries of chemistry knowledge anymore??!!?????

Organikum - 21-12-2003 at 13:52

of course it boils.
of course you will be able to boil some ammonia or methylamine out of an solution of sufficient strength.
Of course there will water come over with the ammonia and methylamine.
Lots of water.

Wolframs method works.
Yours also - except the drying part.
Mine works best.

Thank you very much

Wolfram - 21-12-2003 at 14:37

Thank you very much for your answers. Now where is it written that methylamine boils at -6 C? In Aldrich its written +48C. Ammonia boils at -50 or something like this so I will NOT get a mixture of ammonia and methylamine since ammonia will not condens, but will leave to the air.

unionised - 21-12-2003 at 14:39

The vapour pressure of water at 25 C is about 20 or 30mm Hg. That's about a 30th of an atmosphere. The methylamine will be accompanied by water but about 29/30 of it will be the product you want.
OK, in reality the figures will not be quite that simple due to association. I still think it's about the right order of magnitude. The bulk of the stuff that distills will be the more volatile material.

EDIT
Just seen Wolfram's post.
It is so written in Merck and in Sax's dangerous properties of hazardous materials. OTOH Aldrich gives the Bpt of the solution they sell as 48C

[Edited on 21-12-2003 by unionised]

[Edited on 21-12-2003 by unionised]

Mumbles - 21-12-2003 at 17:00

Perhaps give this a try? http://www.orgsyn.org/orgsyn/default.asp?formgroup=base_form...

I can just get those chemicals much easier than Hexamine.

vulture - 22-12-2003 at 00:47

Don't forget that methylamine might just form an azeotrope with ammonia. Compounds with similar behaviour in water solution often do that.

unionised - 22-12-2003 at 04:36

In theory you can separate them on the grounds of the difference in bas strength, but I wouldn't like to have to.

Wolfram

Organikum - 22-12-2003 at 11:08

methylamine is a gas at roomtemperature.

KABOOOM(pyrojustforfun) - 23-12-2003 at 21:08

Adiabatic: that's the exact reason they didn't mention it! unless they had an otc source for their NM otherwise it's kind of ***** to make NM and convert it to MA

we should seriously take glycine into account.........

Wolfram - 27-12-2003 at 10:14

What is the reference that methylamine boils at 6 C?

the lazy way

Organikum - 10-1-2004 at 16:10

- Dissolve some hexamine in water in a plasticbottle (PET is fine).
- Add double the amount of water needed for dissolving.
- Add quite a lot of Al (foil) or zincfilings or ironfilings or alltogether.
- Add some HCl.
- See the bubbling start.
- Add more HCl from time to time until you smell a salmiac stench.
- Shake.
- Place on heating - 50C is ok
- Shake.
- this is continued over several days until no more salmiac stench is present, if necessary add more metal or HCl.
- Basify.
- Steamdistill.
- Methylamine in good yields.

Using a strong stirrer and Al/Zn/Fe powder speeds up the reaction to about 24 hours to completeness. Plain Al-foil and shaking from time to time may take 2 weeks.
Dont overacidify!
Keep the broth slightly acidic so the metal reacts - not more.

Time
is
the
key

Hey! Thats the hit! Isnt it? No dimethylamine btw. And keep the bottle mostly closed - it can take the pressure, vent it once a day and nosecheck the ammoniumchloride (salmiac) content, then squeeze it and close it again.

shake it baby, shake it.......

EDIT:
Repeated tries and a check of theory showed up that no DI-methylamine but TRI-methylamine is a byproduct of this synthesis.
About 1 mol TRI-methylamine to 3 mole MONO-methylamine.
Sorry my bad.

for a conveniant synthesis of methylamine without the need of zinc or other metals look for a followup post of mine in this thread - after the picture - soon to come to the theatre in your town also....

To honour Polverone: this is a modified procedure after a german patent from 1898.
19th century rulez!

[Edited on 24-2-2004 by Organikum]

guaguanco - 10-1-2004 at 20:37

Quote:

Originally posted by Wolfram
What is the reference that methylamine boils at 6 C?

The CRC lists the BP as about -6 C

unionised - 11-1-2004 at 07:40

's funny, I thought I mentioned a couple of refs to the bpt on 21/12/03.
Anyway, don't forget while playing with mixtures of HCl and HCHO that you can generate
bis(chloromethyl)ether which is really quite bad for you.

[Edited on 11-1-2004 by unionised]

But how does it look like ?

Organikum - 24-2-2004 at 14:17

Thats how it looks like !

Still a little IPA-wet, the crystals get glassclear after this evaporated.

Better method...

Organikum - 24-2-2004 at 14:39

The ratios used:

100g hexamine
100g water
310g HCl 30%
100g ethylalcohol denat.
20g ammoniumchloride

145g Methylamine.HCl in theory

The hexamine from fuel tablets (which are 100% pure here where I live) was dissolved in 100ml water - not all hexamine went into solution. The HCl and the alcohol where mixed and chilled and then slowly added to the hexamine, at start some fumes evolved. This mixture was put in a 2l flask which was equipped with a vigreux column (40cm) and a downright condensor, a thermometer into the flask and a thermometer at top of the column. The column was cooled by a fan (12V/8cm computerpart). Boilingstones (broken flowerpot) were added and heat applied by means of a waterbath.
At 75°C boiling started. The reaction was held at a steady reflux for about 2 hours then some liquid started coming over at 50°C to 60°C (measured on top of the column). Probably the ethylformate - what else. This ceased after about one hour and for the good of it the reaction was refluxed for one more hour. Then the column was removed and the water distilled away under aspirator vacuum. The temperatur in the flask never got higher than 90°C. As the water was mostly removed and a yellow slush remained in the flask, IPA was added and the slush extracted. Three portions of IPA - 200ml/100ml/100ml - brought to a boil and decanted. A snowwhite remainder stayed in the flask - ammoniumchloride.
The extracts which of course contained some ammoniumchloride were joined and set up for distillation. About one third of the liquid was boiled away (azeotropic removal of remaining water) - some heavy bumping appeared at the beginning also fresh boiling stones had been added. This was done to remove remaining water by the azeotrope. The remainder was filtered hot through a flutet filter for to remove the last ammoniumchloride.
The IPA was put on my balcony (a usual freezer might be substituted here) and forgotten. After about 12 hours the jug was full of beautiful crystals, the remaining IPA was poured out and - concentrated again and treated like before.

The crystal were spread out and dried on a hot waterbath - careful - methylamine is VERY hygroscopic!
A chloroform wash produced almost no dimethylamine - I actually guess there was no dimethylamine at and the three grams produced by the chloroform wash were by traces of water present in the chloro.
Yield: 125g, 145g would be theory so thats ok for me.

Mendeleev - 25-2-2004 at 19:51

Why does everyone seem to prefer methods using hexamine? I personally think the hexamine route is a poor idea because it wastes precious hexamine which would be better put to use making RDX, and requires steam ditillation. I personally prefer the ammonium chloride and formaldehyde method I discovered on rhodium. It requires about 2 L of formaldehyde and 1 kilogram of ammonium chloride, both of which are dirt cheap, probably costing around $15 for both. Simply mix, heat until the ammonium chloride is fully dissolved, leave at around 104-106 degrees Celcius for about 3 hours, then increase the heat to evaporate the water, until you see ammonium chloride precipitating. At this point turn the heat off and begin cooling the reaction vessel and its contents to a little under 20 degrees Celsius, and filter the solution (vacuum helps). The filtrate is then transfered to a different vessel and heated to drive off water until temperature reaches 160 degrees Celsius, at which point a vacuum is applied. The vacuum should cause the temperature to drop several degrees, but when it reaches 160 again you are done. Once the methylamine is cooled down all that remains is to wash it with chloroform. I think there are similar methods discussed on other websites. Aside from hexamine and this methods there are also nitromethane, acetamide, Hoffman rearangement, ammonolysis and direct reaction of ammonia and methanol in the presence of a catalyst methods, but all seem much more difficult.

[Edited on 26-2-2004 by Mendeleev]

guaguanco - 26-2-2004 at 10:38

Well, hexamine isn't particularly expensive or hard to get, so it doesn't really matter if you sacrifice some along the way. I suppose it all depends on what starting materials one has access to.

Marvin - 26-2-2004 at 11:06

Since the usual route to hexamine is to mix solutions of ammonia and formaldehyde I really dont see why making it from formaldehyde and an ammonium salt is such a big improvement. Regardless of if you buy your hexamine or have to make it the advantage just seems to be semantic.

[Edited on 26-2-2004 by Marvin]

Organikum - 6-3-2004 at 04:57

The procedure as described can be done with ammoniumchloride and formaldehyde also - no problem. The HCl hydrolizes the hexamine to these two compounds. The the question what to use is academic and depends solely on the availability of the starting material.
So I can buy hexamine OTC and cheap around the corner in form of fuel tablets named "HEXA" (hehe...) , but as I cannot buy formaldehyde OTC I use hexamine. It has also the advantage in my eyes that it is a nice compressed form of formaldehyde and ammonium, not smelling and to store without problems.

If somebody is not able to adjust the ratios used to NH4Cl and formaldehyde 40% aqueoous solution - not my problem.
Goodbye.
:cool:

acx01b - 6-5-2004 at 12:12

well
the man says why not use directly Formaldehyde and NH4Cl:

because you will get 1st Hexamine!

so i ask to you: why not directly use Hexamine ?

then:

does anyone know how to obtain non hydrated ammonia or methylamine from aqueous ammonia or aqueous methylamine freebase ?

I'd expect that CaCl2 would work ?
but maybe im wrong.
Anway, do you know an other way than drying agents ?

[Edited on 6-5-2004 by acx01b]

Organikum - 7-5-2004 at 03:37

Ammonia and methylamine are both gases.

Geomancer - 7-5-2004 at 08:00

The nifty thing about gasses is that they become less soluable with temperature. Heat will drive a lot of ammonia out of solution. Same should work for methylamine. Don't expect it to be quantitative, though.

acx01b - 7-5-2004 at 10:40

same with HCL aq: I expect that CaCl2 or MgSo4 would work to get HCL gaz...

but maybe im completly wrong.

Organikum - 7-5-2004 at 12:52

No you are right - and probably know this very well - heat, as CaCl2 and MgSO4 will drive out HCl - but the same as with ammonia and methylamine driven out by heating you cant expect the gases to be anhydrous.
CaCl2 and MgSO4 wont work very well for ammonia and methylamine though. But you can form the salt, methylamine.HCl or respectivly ammoniumchloride and drop an concentrated aqueous solution of the salt onto excess NaOH or KOH. This will produce the gas. If the NaOH or KOH is admixed with CaO - quicklime - the produced gas will be fairly dry. Otherwise an dryingtube filled with NaOH or better NaOH/CaO will dry the gas completely.

acx01b - 8-5-2004 at 11:36

wow

nice

i'll try it tonight for the pleasure with my little equiment.

but to get some dried NH3 we can use hexamine too no? easier? (dont need to make dried NH4CL 1st)

[Edited on 8-5-2004 by acx01b]

Organikum - 8-5-2004 at 23:25

Quote:

but to get some dried NH3 we can use hexamine too no? easier? (dont need to make dried NH4CL 1st)

I guess you got something wrong here.

If_6_was_9 - 9-5-2004 at 06:53

Has anyone considered this?

https://www.the-hive.ws/forum/showflat.pl?Cat=&Number=41...

acx01b - 9-5-2004 at 11:24

ty vm,

specially the links page's nice: https://www.the-hive.ws/forum/showtext.pl?Cat=&Show=link...

Mendeleev - 23-6-2004 at 07:23

I was wondering if the formaldehyde and ammonium chloride method could be done with lower concentrations of formaldehyde, such as 20% or 30%, by adjusting the amount of formaldehyde added? What I specifically had in mind was could it be done campa-chem style?

Mendeleev - 23-6-2004 at 14:32

Sorry for double postin everyone, I am on an old computer with an old browser and everything is very weird, but I just wanted to add one more question, everyone says to distill the hexamine, HCl mix, but that's not really necessary unless you want to collect the biproduct right? You really just have to mix, heat, evaporate off, filter, and recrystallize right?

Polverone - 23-6-2004 at 19:35

Quote:

Originally posted by If_6_was_9
Has anyone considered this?

https://www.the-hive.ws/forum/showflat.pl?Cat=&Number=41...

How interesting! I believe the prep can be considerably simplified as well. Sulfamic acid, refluxed with an alcohol, produces the corresponding ammonium alkyl sulfate directly. Sulfamic acid is inexpensive, readily available, and far less hazardous than conc. H2SO4. It's a shame this isomerization doesn't take place with higher ammonium alkyl sulfates.

Theoretic - 25-6-2004 at 07:08

The reaction of sulfamic acid with an alcohol gives the alkylammonium hydrogensulfate rather than sulfate:
NH3SO3 + C2H5OH => C2H5NH3HSO4.
A great alternative preparation though.

drat

Polverone - 25-6-2004 at 12:44

curse my wishful memory

Mendeleev - 27-6-2004 at 19:11

I successfully made some methylamine hcl today using the hexamine method. I did the standard 140 g hexamine reaction. To this I added 320 mL of water, and then 480 mL of 31.45% HCl. This is basically Rhodium's method to the dot except I adjusted the volume ratios to fit lower concentration of HCl. The mixture was stirred and refluxed in a beaker for about 1 or 2 hours. There was a white froth or powder at the suface immediately upon mixing the ingredients. The reflux apparatus was a simple piece of saran wrap, tightened with rubber bands, and full of ice in the inverted cone, very similar to brainfever's nitric acid distillation apparatus.

After refluxing I proceeded to boil down the liquid until I got down to half of the original volume. The beaker was cooled and a lot of white precipitate formed, which was filtered. Next the solution was boiled down almost all the way until I noticed a lot more smoke and fish smelling fumes. After cooling the crystals were one big chunk with almost no liquid in them.

After collecting the crystals, they were dissolved in about 250 mL of boiling ethanol and filtered. There was a lot of precipitate left undissolved, the ammonium chloride. I will put this to work making more methylamine hcl with formaldehyde. The ethanol was boiled off untill again, there were lots of fumes and fish smells. Upon cooling the whole mass solidified into a chunk of methylamine with no liquid in it. It is a tad yellowish, but as I have no chloroform I will simply wash it with very cold ethanol, which I hear also works.

The yield so far, 86 g of recrystallized but not washed mehtylamine hcl. I guess I lost a bit because I boiled down too much and left the methylamine melt to vaporize for too long, but I am not too worried as this helps me avoid filtering the solution countless times.

Organikum - 28-6-2004 at 06:15

Use the method with alcohol added, this is faster and avoids dimethylamine formation. (you may have a look at the HIVE for the thread "For the vindication of Eleusis" for detailed discussion).

Ethylalcohol dissolves a good amount of ammoniumchloride, it is no good solvent for extraction and rarly anhydrous. n-butylalcohol would be best, but who has? HOT IPA works well and is freely available - anhydrous.

ORG

Mendeleev - 28-6-2004 at 19:29

I repurified my methylamine hcl with cold ethanol, -15 C. I added 100 mL, decanted, then 50, then 40, and then 30. At 30 mL the color of the ethanol was only slightly tinged yellow. The final yield of pure product was 50 g on the dot. Not very spectacular but its okay. Next time I will add the ethanol at the beginning as suggested.

Reply

Jacked - 1-8-2004 at 17:28

How about Methylamine via Nitromethane doing a Al/Hg amalgamation and piping off the Methylamine? Bubbling it through H2O or maybe Alcohol in a flask sitting on a scale as to calculate saturation amounts? I don't know exactly what I'm talking about but I know this is a method for producing Methylamine. Actually the Methylamine is a by product of the reaction when it is used with P2P or MDP2P... leave out the drug precursor and you got it

[Edited on 2-8-2004 by Jacked]

Mendeleev - 20-8-2004 at 21:00

I noticed something strange. I performed the reaction with hexamine and ethanol as Organikum recommended. The first time I added the hcl/ethanol chilled, the second time not. When the HCl/ethanol was not chilled I noticed a much larger increase in volume during refluxing. In both cases the reaction was refluxed in a sealed evironement at 60-75 Celsius for two hours before distilling, but the first time the total volume went up from around 500 mL to 600 mL, whereas the second time it went from 500 mL to 1L. Why is this?

[Edited on 21-8-2004 by Mendeleev]

JohnWW - 21-8-2004 at 00:52

Partly due to thermal expansion; and another possible reason is that the addition of HCl would have introduced ionic species to the mix, ending up as [CH3-NH3]+Cl-, which would have attracted fairly large volumes of ethanol molecules to themselves as spheres of solvation, distorting the arrangement of molecules in the solution.

John W.

Theoretic - 3-10-2004 at 07:21

I suggest oxidative decarboxylation (OXDCO) of acetamide. Hypochlorite would do the trick:

CH3CONH2 + NaClO => CH3NH2 + NaCl + CO2

Acetamide can be made from acetic acid, chalk/soda and any nonvolatile amonium salt:

2CH3COOH + CaCO3 => Ca(CH3COO)2

Ca(CH3COO)2 + (NH4)2SO4 =>
CaSO4 + 2NH4CH3COO =>
CaSO4*2H2O + 2CH3CONH2 (for example).

Addon to the Zn reduction I posted

Organikum - 4-10-2004 at 05:45

For good results additional ammoniumchloride has to be added or some trimethylamine will be formed.
HCl has to be kept on the very low side, iron works too as reducing agent, it requires higher temperatures and more time though.

Mendeleev - 7-10-2004 at 18:12

Does anybody think I could condense methylamine by passing it through a 300 mm graham condenser filled with a 91% solution of IPA at -25 C?

neutrino - 8-10-2004 at 18:55

I don't see anything wrong with that. Just remember to keep your recieveing container chilled below -6*C.

Mendeleev - 26-11-2004 at 22:37

If you have a substance which is solid at room temperature, but sublimes at a certain different temperature for example, around 150 C, or a solid that melts at a lower temperature and then vaporizes at 150 C, will that solid sublime if you pull a vacuum strong enough to cause a liquid, which boils at 150 C, to boil at room temperature? I ask this because I have been getting low yields of methylamine using the hexamine, hcl, ethanol method and I think I may be boiling away a lot of my methylamine when I boil the water. I also recently acquired a very strong vaccum pump.

[Edited on 27-11-2004 by Mendeleev]

neutrino - 27-11-2004 at 08:53

The liquid boiling doesn’t necessarily mean that the solid will sublime. This depends on the vapor pressure of the substances at whatever temperature you’re using. To get something to boil/sublime, you have to get the vapor pressure and atmospheric pressure the same. You can do this by heating the substance (increasing its vapor pressure) or decreasing the pressure around it. If your vacuum pump is a decent one, then should work.

Mendeleev - 28-11-2004 at 09:55

My point was that, can a solid even have a vapor pressure?

unionised - 28-11-2004 at 10:34

Naphthalene stinks.

neutrino - 28-11-2004 at 16:32

Yes it can. To clarify the previous post, naphaltene sublimes a little at room temperature (because it has some vapor pressure) and thus stinks.

Methylamine & Butanol

FriendlyFinger - 6-6-2005 at 16:29

Swim made some MeNH3.HCl via Hex and methanol. After removing excess NH4Cl, volume was reduced with vacuum in a water bath untill very very thick. If Swim uses Butanol to extract, some water will come over as well. So what will this water more likely bring with it, methylamine or NH4CL?

Kind regards,
FF

Methylamine extraction methods

FriendlyFinger - 9-6-2005 at 17:21

Hi there!

Swim wants to extract Mehn2.HCl with Butanol as easily as possible keeping purity and yield high without going Orange.

Swim added 50g Hex + 155g 30% HCl + methanol + 10g NH4CL set up in a 3 neck 250ml RBF with a packed 250 mm column in a mantle. The methyl formate was distilled over about 3 hours, temp around 31.5 to 36 deg C (I think, can't remember right now). heat was progressivly raised while distilling formate until the reaction temp reached 90 deg C and was kept there for 1 hour. Cooled, filtered, set up in water bath with simple vacuum distilation. reduced till Nh4CL spotted, cooled, filtered, reduced again till very thick and mushy and no more distillate come over.

Now swim is thinking of extracting either of 3 ways;

1) Adding butanol, fractionally distilling azeotrope till dry, decanting then adding fresh dry butanol and simply boiling and decanting. With oil bath at 145 deg C.

2) Adding butanol, boiling decanting, etc pooling, cooling, filtering, distilling the butanol to crash out MeNh2.HCl.

3) The more traditinal method of cooling before it's gets mushy, filtering to collect the MeNH2.HCl and returning filtrate, reducing and pouring into a beaker where it goes solid, then boiling with butanol.

Swim's amine turned orange when using method (1) and no amine collected. That happened in another synth where more HCL was used (100g Hex + 330g HCl) Can too much HCl screw things up? Why did it turn orange?

Regards,
FF

Organikum - 10-6-2005 at 02:57

Turning orange happens after my experience when there are ketones present as adulterants. In my case they were in the denat. EtOH.
When the denat. alcohol was pretreated with NaOH and distilled what left back the polymerized ketones - no orange discoloring was detected anymore.

I always used IPA for extraction. First one or two selective crystallations to crash out most ammoniumchloride and the three portions of boiling hot IPA.
Worked ok for me.

Extracting without crashing out the NH4Cl had proven unfavorable as somehow the methylamine doesnt like to get extracted from heaps of NH4Cl (this problem was also mentioned in the literature - yields got much better after I changed procedure - better but timeconsuming).

Also I quitted attempts drying the methylamine.HCl. For my purposes it was enough to dissolve the wet stuff in EtOH, to add HaOH pellets and to distill the EtOH/MeAm over into some more cold EtOH. Some water is ok in an Al/Hg.

Remarkable is perhaps that one older book says thats carefully extracting the MeAm.HCl with EtOH (96%) is ok and residual NH4Cl is not so much one has to bother with for most uses.

NH4Cl precrashed - is understood.
This would make the trip a one solvent only story - much to my liking. Have to try this though.

Final: At Rhodiums page was a big-scale methylamine from formaldehyde/NH4Cl with pictures. Well, I must say that strangely the "methylamine" as depicted in these pictures looked exactly like my ammoniumchloride always looked like. Just if somebody asks himself how MeAM.HCl may look like I can assure that at least in central Europe it does not look like these pictures showed.
(Literature tells that the crystals of MeAm.HCl and NH4Cl differ distinctly and obviously)

/ORG

FriendlyFinger - 19-6-2005 at 02:16

Damm those ketones! What ratio of NaOH to alcohol do you use to clean? I will use pure 95% EtOH next time. The Denatured alcohol I use has 95% ETOH, 4.25% H2O 0.25%; MIBK, Denatonium Benzoate and Fluoroscein.

I followed your procedure again this time without adding any water, without refluxing first and using a molar equivalent of MeOH. Methyl formate was collected between 31.5 and 36 deg C without refluxing first then holding it there at 90 deg for 1 hour then vacuum distilling, but only got 50% yield after IPA. This was a few days ago and I remember vacuum distilling till rock hard and almost dry before trying to extract with IPA. So does it not matter how wet the crystaline mix is before extracting?

What's the deal with the Vacuum method? Is there a special secret here?
I used Baalchemists writeup. There must be something very very simple here that I still don't understand. 54g hex + 185ml 28% HCL (diluted from 162ml 370g/l 32%) I wish they would write it in grams! not ml. It all dissolved, didn't wait to see hydrolysis, I've used this hex before. Put it straight into a hot water bath and refluxed with vacuum for 3 hours. Liquid temp was 78 deg. Then vacuum distilled for 3 hours untill almost dry. Added 85 ml IPA, boiled for 30 min, decanted, results- maybe 10 flakes of MeHN3.HCL. Jesus.

Summarian, and others at the Hive claimed 80 to 95% refluxing at 65 deg. I believe them, but what's the catch? I've made safrole from catachol but methylamine is still my biggest problem, even the easiest fool proof synths. It's embasasing but true!

Regards,
FF

[Edited on 19-6-2005 by FriendlyFinger]

S.C. Wack - 7-8-2005 at 19:32

In this article, methylamine is alleged to have been made by heating ZnCl2, NH4Cl, and MeOH. At 303C.

That is about all that I can say about it, I have no idea what the table numbers on the second page has to do with the yields on the third. The editors must have been able to figure it out. Anyone want to give it a try?

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praseodym - 8-8-2005 at 23:36

Methylamine can actually be obtained by heating aq ammonia with methylchloride.

skippy - 9-8-2005 at 10:26

Interestingly, I was just reading about the rxn of alkyl halides with ammonia a week ago and found a bit of info that
implies that the rxn is impractical:

http://www.usm.maine.edu/~newton/Chy251_253/Lectures/Amines/...

"A third method of preparing amines involves the reaction of alkyl halides with ammonia or another amine. The reaction of methyl bromide with ammonia, Equation 3, is a simple example.

While reaction 3 looks simple, it is, in fact, tricky to obtain methylamine in good yield. The reason for this is that methyl amine is more reactive than ammonia; as soon as it is formed, it reacts with methyl bromide to produce dimethylamine. This, in turn, reacts with more methyl bromide to generate trimethylamine. Ultimately, tetramethyl ammonium bromide is formed as shown in Equation 4.

The trick required to obtain monoalkylation is to use a large excess of ammonia. By using an NH3/CH3Br ratio of, say, 100/1 or 1000/1, it becomes statistically more likely that a methyl bromide molecule will encounter an ammonia molecule than a methyl amine molecule. Once all the methyl bromide has reacted, the excess ammonia, which has a lower boiling point than the methyl bromide, is boiled off, leaving the methyl amine behind. (Ammonium bromide is also left behind from the reaction of the HBr that is produced in reaction 3 with some of the excess ammonia. This is separated from the methyl bromide during the work-up of the reaction mixture.)"

end quote

Maybe a tenfold excess of NH3 would be OK with purification? I don't know, any comments?

praseodym - 9-8-2005 at 22:21

Hmm...true that this reaction has to take place under very controlled conditions. When excess ammonia is used, all methylamine, dimethylamine, trimethylamine and tetramethylamine will be formed. So anyway to separate the mixture, anyone?

TaurineMonster - 21-10-2005 at 22:50

I read a synth for this scaled up to 3mol, but now can't find it.anyone have it saved somewhere close?

madcease - 8-2-2009 at 06:44

What is the best way to go about storing and transfering MeAm HCL from its salt form into a gas canister for storage and 99% anhydrous usage. Ive read that 50% of base makes the gas but how does one go about filling canister or tank for use later on?

hector2000 - 8-2-2009 at 07:31

easy method:

Methylamine Hydrochloride from Ammonium Chloride and Paraformaldehyde

27 grams of ammonium chloride, 30 grams of paraformaldehyde (molar ratio 1:2), and 90 ml of water were gradually heated. At 80°C a clear solution was obtained, and the temperature was maintained at 104°C for four hours. Slightly more than one-third (9.06 grams) of the ammonium chloride was recovered, whilst 18.96 grams of pure methylammonium chloride were obtained. This equals 86% of the theoretical amount. The amount of dimethylammonium chloride produced was not estimated. It is not suggested from the results of this experiment that paraformaldehyde can economically be used on a large scale with advantage, since, quite apart from the relatively high cost, neither formic acid nor part of the unchanged aldehyde can be recovered as by-products.

Panache - 8-2-2009 at 18:11

Quote:

Originally posted by madcease
What is the best way to go about storing and transfering MeAm HCL from its salt form into a gas canister for storage and 99% anhydrous usage. Ive read that 50% of base makes the gas but how does one go about filling canister or tank for use later on?

As with all gases that are condensable at moderate coldness (eg CL2, NH3, Dimethyl ether, butane etc) it is simply a matter of liberating the gas, drying it then re-condensing to a liquid, pouring it into your cold cylinder and screwing the valve on. Once the cold liquid and cylinder warms up the cylinder becomes pressurised and you have the ability to open the valve and remove the gas or inverting the cylinder to remove liquid.
Having little direct experience with methyl amine i can only speculate. Organic amines are commonly dried using NaOH, so fused pellets in a column would probably be dandy. It's boiling point is not particularly low, -6C or something, so dry ice/ethanol in a cold finger would be overkill but practically the easiest. Amines love those transition metals so probably avoid brass fittings and stick with stainless.

edit-you may want to check the toxicity of methyl amine it may be a bit nasty and/or flammable and you should take precautions accordingly.

[Edited on 8-2-2009 by Panache]

madcease - 9-2-2009 at 22:17

Thanks panache great response i still dont get how with MeAm.HCL is in powder form but needs to be in liquid?
Should this be diluted in MeOH or some other liquid.
Still got me stunned.

azo - 10-2-2009 at 01:56

It is simple to make this primary amine and it doesn't matter which way you make it you are going to get di and tri products
that is why you recryistlize your primary amine with butanol
! dry ethanol works fine to just remember that if you use ethanol with water in it you are going to loose some in the alcohol.
you simply heat the butanol until the primary amine dissolves in and hot filter it leaving di and tri products behind.
when the butanol cools you will soon see your primary amine precipitate before your eyes ! lovely
by the way as one other member said you can't tell the difference between ammonium chloride you will certainly tell the difference when the primary amine is pure. trust me.
and as organikum said you have to seperate the ammonium chloride first.
in relation to storage you can use a vacume desicator to keep it in but i found that it is not needed when your amine is very pure it is very hygroscopic when not pure.
and as for madcease i think you should learn more about chemistry first , i dont no what you are doing with it but i take it you want to do a reductive amination with a ketone or aldehyde if so whether it is hydrochloride or freebase would depend on what reduction procedure you use.

yes methylamine is poisonous in freebase form .

hope this helps regards azo

madcease - 10-2-2009 at 21:00

Azo it doesnt matter what it is used for all i was asking was how to make MeAm.HCL in its gas form and not the salt.
Its alot purer and longer lasting storage as it will not get used just usual experiments.
I know its poisonous but need to know how they get into canister the ones you purchase from shops.

azo - 10-2-2009 at 23:24

[Edited on 10-2-2009 by azo]

Attachment: meth.louisfreeh.html (126kB)
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methylamine

azo - 10-2-2009 at 23:40

http://www.erowid.org/archive/rhodium/chemistry/meth.louisfr...

sorry this is what i meant to give you

regards azo

madcease - 11-2-2009 at 01:41

Thanks azo have read many times but just recently have been thinking about it and still cannot work it out.
Im no chemist as you can tell just an experimentalist and i think by asking someone may have done this before and might have some knowledge to share with me.
I know it has to be in FB form for most reductions but wanting to store in gas canister.
Any help would be greatly appreciated even a PM.

With the hexy method does it make a difference in yield if a weaker concentration of acid is present or stronger? Eg 37% HCL or 28% HCL as you can never be too sure.
Does water in the reaction make a difference or is it mainly to HCL doing all the work.

madcease - 11-2-2009 at 01:43

I have been told by numerous people not to do the hex and hcl relux in stainless steel as it will react with the metal. Is this true or are they just refering to the acid reacting and not the MeAm?

pareidyllic - 30-3-2009 at 00:37

Quote: Originally posted by KABOOOM(pyrojustforfun)

we should seriously take glycine into account.........

This is something I've wondered about but never seen discussed. Is there any reason that decarboxylation of glycine wouldn't work for this?

Sorry for bumping a somewhat old thread, I don't know how this forum feels about that kind of thing.

PHILOU Zrealone - 31-3-2009 at 01:52

Quote: Originally posted by madcease

I have been told by numerous people not to do the hex and hcl relux in stainless steel as it will react with the metal. Is this true or are they just refering to the acid reacting and not the MeAm?

Source of nascent NH3 and HCl both complexing and corroding materials for transition metal used in stainless steel...

madcease - 31-3-2009 at 02:02

Just as i thought. If a solution of Hexamine, HCL, H20 has been added together. One would have thought the Ammonia Chloride would crash out immediately and then reacts.
Have seen a reaction done where no Ammonia has precipitated even after 8 hours which makes me believe maybe the solution of HCL was too concentrated?

Is the HCL acid touchy in regards to this process as ive seen most of them in the past precipitate with AmChloride.

PHILOU Zrealone - 31-3-2009 at 03:59

Quote: Originally posted by madcease

Just as i thought. If a solution of Hexamine, HCL, H20 has been added together. One would have thought the Ammonia Chloride would crash out immediately and then reacts.
Have seen a reaction done where no Ammonia has precipitated even after 8 hours which makes me believe maybe the solution of HCL was too concentrated?

Is the HCL acid touchy in regards to this process as ive seen most of them in the past precipitate with AmChloride.

Hexamine hydrochloride doesn't hydrolyse very fast; it is also quite soluble in water just as NH4Cl is...

[Edited on 31-3-2009 by PHILOU Zrealone]

madcease - 31-3-2009 at 04:06

Will the reaction still work if there is no Solids of NH4Cl floating around whilst refluxing.
Reason asked is NH4Cl is very soluble in water and have seen other reactions where it is seperated from the water.

Maybe that is because there is so much water in the mix.
I think by adding some alcohol helps with this reaction not to get over temps as such

Formula409 - 25-6-2009 at 20:47

I have a question. In Eleusis's prep with Methylamine HCl via metal/HCl reduction, he says:

Quote:

*CAUTION*
The lower nitroalkanes form shock and/or temperature sensitive EXPLOSIVE compounds with amines and hydroxides. BE CAREFUL, DAMNIT! You have been warned.

What are these compounds? Should I be worried when basifying and distilling my reaction mix? I'm more than ready to give a Zn/HCl reduction a go but naturally I don't want to get exploded lol.

Formula409.

The_Davster - 25-6-2009 at 21:06

Nitronate salts. If I remember correctly they are harmless in solution and are only an issue once dry.

kmno4 - 26-6-2009 at 05:36

I have just evaporated CH3NH3Cl solution [ prepared from absorbing CH3NH2 gas in HClaq; gaseous methylamine was released (by adding NaOH) from brown, impure product of reduction of CH3NO2 with Fe/HClaq ).
Quickly, cheaply and easily

On the picture : about 0,6 mole of hydrochloride

[Edited on 26-6-2009 by kmno4]

ItalianXKem - 26-6-2009 at 14:26

but CH3NH2 + HCl = CH3NH3(+)Cl(-) ?
however
can you make :
a luminol synthesis step use Na2S2O4 to reduce NO2- to NH2-
you can find nitromethane (typical is used for propellant in rocket model)
and N2S2O4 , react
after you have MethylAmine CH3-NH2
pay attention , methamine is stinky and toxic , high
also maybe how the monomethylhydrazine & co
is carcinogenic , teratogenic or sim bad failures in body
after make a salt with hydrochloric acid HCl
bye , night

Vogelzang - 28-6-2009 at 04:37

Alcoholysis of sulfamic acid produces ammonium akyl sulfates. On page 629 of the attached article it discusses an example where methanol refluxed with sulfamic acid for several hours yields ammonium methyl sulfate. Ammonium methyl sulfate rearranges at high temperature to methylamine sulfate.

See ammonium.methyl.sulfate.pdf here
http://psychedelichosting.info/Ionium/Rhodium/pdf
or http://80.244.243.200/archive/rhodium/pdf/index.html

Attachment: ie50342a005-sulfamates.pdf (705kB)
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jon - 7-7-2009 at 17:53

call me oldschool what's wrong with the traditional way of making methylamines????
if it works why reinvent the wheel?

Sedit - 7-7-2009 at 18:49

Because if we stoped at the wheel people would not be flying around in airplanes right now. Its all about progress.

manimal - 9-7-2009 at 14:48

I'd like to contribute an improvement to Organikum's ethanol procedure. The reactants are combined in the ratios set forth, but instead of refluxing them, they are confined under pressure in a hot water bath. Thus may or may not be an improvement, but I view it as such because it requires little or no attention when running.

A brandy bottle with a screw-on cap was employed, and the mixture was held in the water bath at 85-90C overnight (approx. 14 hrs). Then it was opened and the liquids boiled off and worked up as per usual. Methylamine was obtained in an as yet unmeasured quantity, but no formaldehyde odor was detected when boiling off the solvents. When working up the traditional method, it had sent me retreating with eyes watering severely.

Ethyl formate smells of rum according to the literature. I guess it could smell like rum; it's been a very long time since I smelled rum. To me, it smells exactly like ether-based starting fluid.

Engager - 10-7-2009 at 04:21

Quote: Originally posted by Vogelzang

Ammonium methyl sulfate rearranges at high temperature to methylamine sulfate.

Is it possible to produce monoethylamine salt by means of rearrangement of ammonium ethyl sulfate? If so, what is temperature required for isomerization?

Polverone - 10-7-2009 at 08:42

Quote: Originally posted by Engager

Quote: Originally posted by Vogelzang

Ammonium methyl sulfate rearranges at high temperature to methylamine sulfate.

Is it possible to produce monoethylamine salt by means of rearrangement of ammonium ethyl sulfate? If so, what is temperature required for isomerization?

Unfortunately it is not possible according to this article.

Sedit - 10-7-2009 at 18:17

Vogelzang do you have references that show more indepth the process because I have attempted a .5 Sulfamic to 1 MeOH molar ratio and there appears to be no reaction after two hours of reflux as the Sulfamic does not dissolve.

I have since added equal volume of H2O in hopes that it will push any reaction along so we will see but none of the papers provided appear to exemplify how the reaction is carryed out in any detail.

Engager - 11-7-2009 at 04:03

Yesterday i have tested this method in attempt to produce ethylamine hydrosulfate. 300 ml 97% ethanol was refluxed with 100g of sulfamic acid, solid quickly dissolved and reflux was continued for 2 more hours (3 hours total). Solution is then allowed to cool and small ammount of lustrous solid precipitated, witch gave white precipitate with SrCl2 solution - that was NH4HSO4 produced by water hydrolisys (C2H5OH + NH2SO3H => C2H5OSO3NH4 ; C2H5OSO3NH4 + H2O => NH4HSO4 + C2H5OH). Solution was filtered and distilled to remove solvent. About 250 ml of C2H5OH was collected by destilation on water bath, witch was then removed and evaporation was continued on open flame to force complete removal. 50 more ml of liquid was collected. Temperature was raised to about 150-190C and mixture in reaction flask started to foam, foaming slowly subsided while temperature of reaction mixture reached ~290C. Mixture maintained at this temperature for 15 minutes and allowed to cool to crystallize the melt. Product is crystalline solid almost insoluble in alcohol and forming white precipitate with SrCl2 solution (sulphate presence). Wonder what this product is, so i want to use melting point to identify it, but can't find ethylamine hydrosulphate in avialable literature. Somebody knows melting point of ethylamine hydrosulphate?

Formula409 - 11-7-2009 at 07:09

Quote: Originally posted by Engager

Yesterday i have tested this method in attempt to produce ethylamine hydrosulfate.

Supposedly, that reaction produces ammonium hydrosulphate and ethene, so bear that in mind when identifying your product. It's quite unfortunate that ethylamine and higher amines cannot be produced using this method - maybe you'll prove us wrong

Formula409.

Vogelzang - 11-7-2009 at 09:43

I think the MeOH has to be anhydrous, Sedit.

Sedit - 11-7-2009 at 10:03

Nothing appeared to happen at all other then the MeOH taking on a slightly yellow tinge when it was anhydrous yet I added a bit of H2O and some oil appeared after a few minutes on the surface of the mixture. After cooling large crystals(.25-.5 inches) the shape of benzene appeared and settled on the bottom. They are very thin plates and fragile looking.

I am assuming for the time being that the thin(1mm or so) top oil layer is the product and the crystals are sulfamic acid precipitate but I haven't much time to look into it just yet.

Vogelzang - 11-7-2009 at 14:46

According to the Merck Index, sulfamic acid is sparingly soluble in alcohol and methanol (alcohol probably refers to ethanol). The ie50342a005-sulfamates.pdf reference says sulfamic acid is slightly soluble in methanol. Maybe you have to reflux it longer and use stirring. Maybe the product, ammonium methyl sulfate, is also slightly soluble or insoluble in methanol. Water hydrolyzes both sulfamic acid and the product.
See US patent 1931962, German patent DE558296

The ammonium.methyl.sulfate.pdf article here http://tinyurl.com/lp8dkq is the same as the one here: http://www.rsc.org/ejarchive/CT/1896/CT9140502762.pdf

See also http://en.wikipedia.org/wiki/Sulfamic_acid

[Edited on 11-7-2009 by Vogelzang]

Jor - 11-7-2009 at 15:05

Maybe the following method may be useful for people who have easy acces to phthalic anhydride.

http://en.wikipedia.org/wiki/Gabriel_synthesis
http://www.organic-chemistry.org/namedreactions/gabriel-synt...

Phthalimide is VERY easily produced, simply by heating phthalic anhydride with urea. You will get a melt wich will suddenly froth up, indicating the end of the reaction. I have done this and it is easier than making aspirin. However, phthalimide sublimes easily and you get a lot of phthalimide smoke , wich is teratogenic AFAIK, so outside is adviced

I'm not sure how the next step should be done (what solvent?), but I guess just adding the phtalimide to aq. KOH and bubbling in MeBr would be sufficient. MeBr is very easiliy prepared, unlike MeI or MeCl, simply by adding a MeOH/H2SO4 by dropping funnel to a boiling alkali-bromide solution, then condensing H2O/MeOH/azeotropic HBr, and leading the MeBr gas straight into the potassium phtalimide solution.
Then you would need to hydrolyse. According to a source (can't find it at the moment, to lazy to search, somwhere in google.books), base is suficient.
Then extract the amine (ether?), and lead HCl (H2SO4+NaCl) in the solvent to precitipate the pure HCl salt of the amine.
Phthalic acid can be recovered by adding HCl to the remaining aqeous soilution, precitpating phthalic acid. I think this is easily converted to phthalic anhydride by heating.

Just and idea, I'm probably not going to try this as I don't have any use for these amines.

[Edited on 11-7-2009 by Jor]

UnintentionalChaos - 12-7-2009 at 08:50

I would like to announce success in producing the ammonium methyl sulfate. I will conduct the thermal rearrangement soon and report on yields.

A 250mL RB flask was charged with 22.28g of sulfamic acid, finely powdered in a mortar and pestle and 100mL of anhydrous methanol. A stirbar was added and the flask was set up for reflux with a calcium chloride drying tube. The mixture was brought to a heavy reflux under stirring and maintained that way for an hour and a half at which point the sulfamic acid had completely dissolved. Reflux was maintained for an additional 45 minutes and then the solution was allowed to cool to room temperature. No crystals formed, so the solution was transferred to a 400mL beaker and boiled down to 40% of it's original volume. At this time, a drop of solution was mixed with a drop of concentrated strontium chloride solution. No precipitate formed, indicating the reaction mixture was effectively free from sulfate ion contamination. On slow cooling, elongated, translucent white plates seperated from solution. These were broken up with a stirring rod, and vacuum filtered through a medium porosity fritted glass buchner funnel. They were washed with 25mL of ice cold methanol, transferred to an evaporating dish, and placed in a dessicator over concentrated sulfuric acid. The dried crystals weighed 13.79g (46.5% of theoretical) and are extremely soluble in water, deliquescent in humid air, but reasonably stable in dry air.

The filtrate was boiled down to 15mL in hopes of getting a second crop of good crystals, but when cooled, tons of tiny acicular crystals formed which solidified the mixture. A small piece of the damp crystals were dissolved in two drops of water and tested with strontium chloride again. Only after a few minutes did the faintest cloudiness appear, which may have been due to hydrolysis of the methylsulfate anion in that period. Since there was no appreciable sulfate contamination, the crystal slush was placed in the dessicator to dry for later thermal rearrangement experiments.

Does anyone know of any insoluble methylsulfate salts at all? Information seems to be spotty and from what I can tell it solvates just about everything.

[Edited on 7-12-09 by UnintentionalChaos]

Sedit - 12-7-2009 at 09:49

Congratulation.
Now I have to figure out whats going wrong over in my neck of the woods.

The only thing I could possibly think is that my Sulfamic is not Sulfamic acid. I have used it many times for septic systems as im a plumber by trade and this has been sitting on my shelf for sometime. The label has since worn away but it appears to be the same stuff I have seen many times. Since Sulfamic acid hydrolyses in H2O perhaps the fact that it has been sitting around for years has ruined it.

Im going to get some brand new Sulfamic and attempt this again to see what I can find out.

UnintentionalChaos - 12-7-2009 at 10:09

Quote: Originally posted by Formula409

Quote: Originally posted by Engager

Yesterday i have tested this method in attempt to produce ethylamine hydrosulfate.

Formula409.

Just a thought here, but can an inert solvent be used to generate the ammonium alkylsulfates of long-chain alcohols, then these destructively distilled to yield the terminal alkene?

Perhaps the esterification need not even be carried out. I know sulfamic decomposes when molten, but perhaps it'll still work as a molten fusion.

[Edited on 7-12-09 by UnintentionalChaos]

Vogelzang - 12-7-2009 at 11:22

I wonder how ammonium methyl sulfate would work for making phenolic ethers. See

US patent 2490842 Anisole manufacture
Column 2 lines 6+
The methyl sulfate may also contain a metal substituent on the sulfate radical, as in the case of sodium methyl sulfate or potassium methyl sulfate, it may contain an ammonium substituent as in the case of ammonium methyl sulfate, or it may contain a hydrogen substituent as in the case of methyl acid sulfate.

US patent 2529887 Process for the preparation of anisole
Column 5 lines 30+
Suitable methylating agents for phenol include, for example, a methyl sulfate having the methyl group directly attached to the sulfate radical such as dimethyl sulfate, sodium methyl sulfate, potassium methyl sulfate, ammonium methyl sulfate, or methyl acid sulfate; also methyl halides such as methyl chloride, methyl iodide, and methyl bromide; and organic methyl esters such as methyl acetate.

UnintentionalChaos - 12-7-2009 at 17:27

I repeated the above procedure tonight, using 50.05g of sulfamic acid and 100ml of anhydrous methanol. I do not have yield numbers yet, but will add them to this post when I do. It took 3 hours and 45 minutes of reflux with stirring for complete dissolution/reaction of the sulfamic acid. I continued reflux for another 45 minutes to ensure the reaction was complete.

So, this begs the question, which do you value more, your solvent or your time?

Update: Simple slow cooling of this reaction mix down to ice-bath temperatures followed by vacuum filtration (I omitted the methanol wash this time) gave 39.44g of glittering white crystals (59.2% of theoretical). The secondary crops are still drying.

Here's a little teaser: the first crop of ammonium methylsulfate crystallizing out upon cooling. The picture of the dried crystals was significantly more boring.

[Edited on 7-13-09 by UnintentionalChaos]

Sedit - 12-7-2009 at 17:40

I value my solvents more. The time spent is something I enjoy but shelling out money for more solvent is not

.

Just as a side note to everyone ignore my previous post because after running some test it has become obvious that my Sulfamic acid is not that. This is a good thing as sulfamic is cheep I can attempt another run with better materials now and hopefully arrive at what I want this time.

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