Author Topic: Methylamine in Ethanol instead of Methanol (Read 3719 times)

scram · « **on:** October 24, 2002, 11:01:00 PM »

Why the hell is everyone bubbling methylamine into methanol when ethanol can hold 33%? Wouldn't this make more sense in the NaBH4 method?

Rhodium · « **Reply #1 on:** October 24, 2002, 11:53:00 PM »

Many people can't get ahold of ethanol without a lot of denaturants which can screw up the reaction (as some people still drink solvents for fun), and ethanol is also more cumbersome to dry than methanol.

But assuming that you could choose between 99.5% ethanol and 99.5% methanol for the same price, sure ethanol would be a good choice.

scram · « **Reply #2 on:** October 25, 2002, 01:13:00 AM »

In addition, ChemACX has a supplier name TCI advertising "40% in Methanol" Is this a typo or am I misunderstanding something here?

http://chemacx.cambridgesoft.com

Rhodium · « **Reply #3 on:** October 25, 2002, 02:14:00 AM »

No, that's true, $25 for 500ml. But, if you live in the US, forget buying methylamine from a chem supplier.

BlingBling · « **Reply #4 on:** November 25, 2002, 11:45:00 PM »

What is the point of bubbling methlyamine into methanol during the NaBH4 reduction?

My only thought could be making the MeAm basic? Is this close to correct?

Osmium · « **Reply #5 on:** November 26, 2002, 12:03:00 AM »

> What is the point of bubbling methlyamine into methanol
> during the NaBH4 reduction?

It's bubbled in before the reaction, and its purpose is converting a ketone into a secondary, methyl-substituted amine!!

I'm not fat just horizontally disproportionate.

BlingBling · « **Reply #6 on:** November 26, 2002, 12:10:00 AM »

I meant, why is bubbled in, instead of disolved in?

Sorry.

Osmium · « **Reply #7 on:** November 26, 2002, 12:14:00 AM »

Because methylamine is a gas under standard conditions.

I'm not fat just horizontally disproportionate.

BlingBling · « **Reply #8 on:** November 26, 2002, 12:19:00 AM »

Methylamine, made via nitromethane & al/hg, disolved in solvent, is really a gas? Is the ph of the gas basic? Is that why MeAm. hcl is bubbled through a basic solution? Freebase MeAm= MeAm gas?? Confused

PolytheneSam · « **Reply #9 on:** November 26, 2002, 12:22:00 AM »

95% grain alcohol is sold in some states in the US. Has anyone seen it in Europe?

http://www.geocities.com/dritte123/PSPF.html

The hardest thing to explain is the obvious

pHarmacist · « **Reply #10 on:** November 26, 2002, 01:54:00 AM »

But you can allways buy Denaturated Alcohol at your local Gas Station. The only addons are compounds that make it undrinkable.

"Turn on, Tune in and Drop Out"

terbium · « **Reply #11 on:** November 26, 2002, 02:23:00 AM »

Is the ph of the gas basic?
Methylamine freebase is a gas and is strongly basic.

Is that why MeAm. hcl is bubbled through a basic solution?
Methylamine hydrochloride is a solid.

Freebase MeAm= MeAm gas??
Yes.

Questions like these belong in the Newbee Forum.

Baseline Does Not Exist.

Rhodium · « **Reply #12 on:** November 26, 2002, 05:53:00 AM »

pharmacist: that's not true - there are usually coloring agents, ketones and other more or less reactive stuff added as denaturants. I have never been able to clean gas station ethanol into something usable for chemistry, not even by fractional distillation. That's why I used to do this:

Post 382057

(Rhodium: "Sodium acetate and ethanol from ethyl acetate/lye", Chemistry Discourse)

Osmium · « **Reply #13 on:** November 26, 2002, 10:18:00 AM »

> pharmacist: that's not true - there are usually coloring
> agents, ketones and other more or less reactive stuff
> added as denaturants.

Not always. The stuff I can easily buy is colourless and contains only a small amount of denaturant. I don't know exactly what is used in the cheap OTC stuff, I assume some pet ether fraction, bitrex, MEK or IPA and traces of pyridine. I never bothered to clean it up and used it straight out of the bottle with good results.

If you order denatured EtOH from a chem supplier you can often decide which denaturant will be present. Fluka for example used to offer EtOH with all kinds of different and known denaturants. But compared to the €1.50 OTC stuff that EtOH is way overpriced.

> I have never been able to clean gas station ethanol into
> something usable for chemistry, not even by fractional
> distillation.

That's the whole point of denaturing, making it absolutely impossible (or at least too damn difficult and costly) to clean it up so that nobody will ever be able to drink it without getting seriously sick. Many have tried so far, but most if not all never succeeded. It's the state protecting its tax revenue. That's why clean EtOH is so expensive even though it's dirt cheap to produce it industrially.

I'm not fat just horizontally disproportionate.

Rhodium · « **Reply #14 on:** November 26, 2002, 11:08:00 AM »

I said usable for chemistry. The EtOH can have any THF/hexane/toluene fraction in it (and if intended as a solvent rather than a reagent, then MeOH and IPA are OK as well), as long as there are no ketones or "unknowns" in it...

Chromic · « **Reply #15 on:** November 27, 2002, 05:40:00 AM »

Why would someone need the azeotrope of ethanol? Are you sure you weren't drinking it?

I could undertand a need for anhydrous ethanol, but... you've baffled me.

Rhodium · « **Reply #16 on:** November 27, 2002, 06:37:00 AM »

I used a lot of that ethanol back in the days when I was too ignorant to know that I could substitute it for methanol and/or IPA in 99% of the cases where "96% ethanol" or "alcohol" was specified in the chemistry literature. I never had a chemistry mentor when I was a teen, I only learned from books, and they never tell you to skimp on anything when you don't have exactly what's specified in a synthesis.

Osmium · « **Reply #17 on:** November 27, 2002, 11:33:00 AM »

> Why would someone need the azeotrope of ethanol? Are you
> sure you weren't drinking it?

All the ethanol sold over here is azeotropic, since it is usually produced by fermentation. Even hydratisation of ethene will produce azeotropic EtOH. If you want anhydrous, you have to resort to other means of drying. Since that is an additional step which is unnecessary for most common EtOH uses, reduces yield, requires anhydrous conditions, requires additional energy and production facilities most of not all of the EtOH available OTC will be close to the azeotropic composition.

> I could undertand a need for anhydrous ethanol, but...
> you've baffled me.

Azeotropic EtOH is the perfect solvent for Al/Hg reactions, IMHO.

I'm not fat just horizontally disproportionate.

raffike · « **Reply #18 on:** November 27, 2002, 04:34:00 PM »

One company over here uses phenylacetone as denaturant(of course in so small quantities that it can't be extracted out)

A friend with speed is a friend indeed

Barium · « **Reply #19 on:** November 27, 2002, 04:56:00 PM »

Phenylacetone as a denaturant for ethanol?! I wish! Are you absolutely sure it isn´t methylethylketone (MEK)? Does the label state that it is P2P? How have you verified this?

Catalytic hydrogenation freak

raffike · « **Reply #20 on:** November 27, 2002, 05:35:00 PM »

It was so that this company was raided by police cuz cops suspected they were selling some spirit to black market instead denat'ing and found about 15 liter of "Ketone that is used as amphetamine precursour" and i assumed it was P2P,what else could it be,right?Anyway Ghettone was not confiscated cuz they indeed used it to denat spirit,of course lot of it dissapeared but hey,shit happens all the time,right?

A friend with speed is a friend indeed

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Author Topic: Methylamine in Ethanol instead of Methanol (Read 3719 times)

scram

Rhodium

scram

Rhodium

BlingBling

Osmium

BlingBling

Osmium

BlingBling

PolytheneSam

pHarmacist

terbium

Rhodium

Osmium

Rhodium

Chromic

Rhodium

Osmium

raffike

Barium

raffike