MDA with NaBH4 and am acetate review.

[sunlight]

Well, we have tried to reproduce the conditions that yielded a 60 % time ago, TSII excess of am acetate to ketone.
We tried a first small scale test with 5 times the weight of acetate from ketone, saturating solvent, and silica gel all the time, and it gave a little 25 %.
A second test with similar conditions, but adding acetic acid to bring ph to 5.5 and promte imine formation, stiring 2 hours before cooling and addition of NaBH4 gave similar yields, 23.5 %.
Using LabTop's proportions in previous runs gave the same more or less.
So we initially conclude that we can't expect more than a 20 or 40 % if we are lucky with this reaction.
It seems that there was some mistakes that gave me the impression of a 60 % yield, it was a small test and solvents were not dried before crystals, so may be other salts were present, but having mp was checked and right, the biggest mistake could be weighting ketone. Strange, but I can't find other explanation.
May be with saturated ammonia we can get better results.

[flipper]

Are Labtops ratios for MDMA correct and is that step with 8 times the volume of the ketone really necessary. If it is I dont like it. 200 liters water for a 25 kilo batch requires one big fucking tank.    

[Antibody2]

Sunlight, those yields are more in line with what has been realized round here, although 15% was average 25% the best acheived. was beginning to have self doubt, glad to hear it is the rxn.

finally gave up on it, think that iso > pseudonitrosites(92%) > nitroalkene (72%) > nitroalkane(?) > amine(40-55% from alkene) is higher yielding overall and makes better use of precious NaBH4, IMHO.(90g safrole gave 30+g amine) with no ketone to distill.
"All those memories lost like rain..."

[zooligan]

So where are the nearly quantitative yields which LaBTop professes?  Is the rxn with methanolic methylamine to produce MDMA more efficient?

z

"And if we don't get some cool rules ourselves, pronto, then we'll just be bogus too!"

[Osmium]

> Is the rxn with methanolic methylamine to produce MDMA
> more efficient?

Yes. NH3 is the worst to aminate with, no matter what procedure you use. The imine formation is the most difficult with NH3, all other imines form more readily even when water is present.

[Semtexium]

If your contemplating a 25kg batch, the size of your fucking tank should be the least of your worries.  Tanks are CHEAP ASSED, even new, in compairson to the chems, etc involved...
            Mean People Suck             

[sunlight]

MDMA with LabTop ratios, even without silica gel in imine formation, produce incredible yields with pure ketone, from 84 to 90 %, and using silica gel our best was at least 91 %, may be a little more (I'm considering the error weighting ketone is the worst case, it has been a recent and small test).
It's the best by far. Clean, easy, avoids mercury salts...
And yes, antibody2, after that test, we made three more trials using LabTop ratios, and we were atonished seeing our poor yields, from 15 (even 10 from a friend) to near 40 %. We thought that scaling didn't work, and may be AA should be in big excess, but finally it is what it is.
By the way, about the pseudonitrosite way, how would you go from the nitroalkene to the amine ? Beaker's 2CH way ? It needs fucked THF and Pd/C (homemade didn't work), and I never got his impressive yields (80>%), but a 65 %. Anyway it could be a good alternative.
Flipper, you don't really need to add so much water, we don't. After reaction (and filter if you have used silica gel and it was not previously removed, what seems now better), we evaporate the solvent with an aspirator using hot/boiling water. First slowly, methylamine produces some foam, then we add water (it prevents bumps) and evaporate the solvent, and then may be add a bit more of water and extract with your prefered solvent. It takes more time, but then you are working with domestic volumes, and you use less solvents what means breathing less toxic things. We love evaporations.

[terbium]

MDMA with LabTop ratios, even without silica gel in imine formation, produce incredible yields with pure ketone, from 84 to 90 %, and using silica gel our best was at least 91 %, may be a little more (I'm considering the error weighting ketone is the worst case, it has been a recent and small test).

I just wanted to emphasize this. It is what I have been saying repeatedly for the year that I have been here. Silica gel is of no benefit in the preparation of the methylimine of P2P or MDP2P. Difference in yield, after reduction, of the n-methylamphetamine, with or without the use of silica gel will be negligible. The use of silica gel in the preparation of the methylimine of P2P or MDP2P is nothing but a, relatively benign, superstition.

[Rhodium]

This assuming that an anhydrous alcoholic solution of methylamine is used, right? There should be a measurable difference in yield, but what you win on the water removal, you might lose on the product adsorption on the silica gel.

Can I have a scientific comparison where two identical runs are made, one with and one without silica gel, performed by the same person?

[terbium]

This assuming that an anhydrous alcoholic solution of methylamine is used, right?
Reagent grade methanol and methylamine gas from dripping aqueous methylamine hydrochloride onto NaOH pellets and drying over NaOH pellets. If some one were to feel the need to dry their methanol it should be done before preparing the methylamine solution or mixing with the P2P. As I have said though, Freifelder claims a 90+% yield of methamphetamine via catalytic hydrogenation when using 30% aqueous methylamine.

There should be a measurable difference in yield, but what you win on the water removal, you might lose on the product adsorption on the silica gel.
Well, since it is an equilibrium reaction, certainly there would be a theoretical increase in the amount of methylimine if the water of formation was removed but since the methylimine appears to be strongly favored (the flask containing a 100 gram batch of P2P warms noticeably after the methylamine has been added) whether there is a noticeable difference would strongly depend on the sensitivity of ones technique; after all, without the silica gel one can get 80-90(+-10)% yields.

[terbium]

Can I have a scientific comparison where two identical runs are made, one with and one without silica gel, performed by the same person?

How about

Post 209000

(sunlight: "Re: MDA with NaBH4 and am acetate review.", Methods Discourse) ?

[Rhodium]

I wanted details, not merely data, as I'm planning to write a NaBH4 reductive amination review soon. But perhaps I should ask Sunlight directly about how he and his team are doing the reaction.

So - Sunlight - Can I have a detailed writeup of your personal technique (including workup, with removal of the formed borates, extraction, distillation and crystallization) to achieve those yields?

[LaBTop]

Sunlight has now the AA/NH3 procedure to try a next run.
Critical factor: give the imine time to form at roomtemp.
Then saturate with extra NH3 gas and a few more things, he'll report back.
Small batch (1 gmol) reportedly an 81% yield w/w, big batch (1.23 kgmol) a 61.36 % yield w/w with messy labtechniques.

Little thing for Terbium to think about: how much NH3 gas dissolves in 1 second in 1 liter water? What happens when boro comes in contact with water?

And I repeat it again; seen with my own eyes:
(in a near 100% humid country, but a new airco all the time working) 23 tests with P2P with no drying of anything: no product at all, only the -ol.
Then proceeding drying one solvent after the other, then drying the imine step, bamm, near quantitative yield of Meth.HCl.

The only thing I can come up with to give an explanation for our differences: Perhaps the officially bought methanol was contaminated with too much water, but honestly said, I don't believe it, the same methanol was used in other water sensitive procedures, no problem. And the methanol was dried, no effect. Only when the imineforming was dried, result. LT/
WISDOMwillWIN

[LaBTop]

Rhodium, if I get you right here, you are referring to Sunlights "incredible" results with my method?

Post 209000

(sunlight: "Re: MDA with NaBH4 and am acetate review.", Methods Discourse)

Why don't you ask me, Gyrogearloose, Methylman, Baalchemist, Terbium, Cesium, Rev_drone, Sumerian and numerous more people who reproduced my method in the past and posted the results?

Do you have the chance to actually do the reaction? If not, how on earth can you write an objective review?

And all details and data you could ever wanted are in my sticky threads, I don't think these reproductions were made reading the New York Times.
Are they really unreadable? Don't think so, seeing all the people who proved to understand it.

I have no problem with someone who wants to write a scientifical review, but it is a bit strange when the originator of the method + all reproductors are left out of the information gathering.
Do you think all these people can not be trusted for their posted results, or is there something I really misunderstand here? Do you want to have as many write ups as possible? LT/  
WISDOMwillWIN

[Rhodium]

I didn't say that I wasn't going to include your and others views on the topic. I have gathered over 100kb of data on this reaction, and I was going to compile them to one single document with pictures and theory. You are correct, I want as many writeups as possible, to extract the best details from every one of them.

[lugh]

One possible hypothesis that reconciles LaBTop's and Terbium's findings as far as the necessity for silica gel during the sodium borohydride reductive amination is that a very large opaque milk tank can retain much more water on the sides undetected than a transparent Pyrex flask  

[LaBTop]

Sorry for my cranky reaction, some little critter was hitting me repeatably with one of it's toys, you get a bit nervous from that sometimes, when you want to concentrate.
In that case I'm glad you took the time to gather all the information, wait till Sunlight returns for AA/NH3 results.
Am pretty curious for the write-up in it's final form. Ehh, sorry again,

Lugh, the Meth tests were done exactly as described in the One Pot Ice, in a 2 liter erlenmeyer etc. Never felt the need to do more, only helped out to think about big scale meth properties (ehh, here at the board).

I HATE the METH effects on people I once respected! LT/
WISDOMwillWIN

[terbium]

Little thing for Terbium to think about: how much NH3 gas dissolves in 1 second in 1 liter water?
I don't get the point of this question.

What happens when boro comes in contact with water?
A little bit of the NaBH₄ decomposes, making the solution strongly basic, and the rest of the NaBH₄ goes into solution unchanged. I have used NaBH₄ that had been stored in bottles having a metal cap with paper liner; the borohydride had absorbed so much water that it had turned into a rock but it would still give good yields cooking meth.

And I repeat it again; seen with my own eyes:
(in a near 100% humid country, but a new airco all the time working) 23 tests with P2P with no drying of anything: no product at all, only the -ol.
Then proceeding drying one solvent after the other, then drying the imine step, bamm, near quantitative yield of Meth.HCl.
And all I can say is that I have cooked lots of batches of meth (100-200 gram quantities of P2P) using NaBH₄ as the reducing agent and got the desired amine in about 80% yield based on the weight of P2P. A small amount of presumed -ol would be formed and could be isolated, depending on how I did the workup, but it was never much.

The only thing I can come up with to give an explanation for our differences: Perhaps the officially bought methanol was contaminated with too much water, but honestly said, I don't believe it, the same methanol was used in other water sensitive procedures
I don't think that was it either. My opinion is that the imine formation is just not very water sensitive. I think that the equilibrium strongly favors formation of the imine from P2P and methylamine. As I have pointed out, Freifelder reports a 90% yield of methamphetamine via catalytic hydrogenation when the methylamine source was a 30% aqueous solution. That the equilibrium favours the imine can also be infered from the fact that the reaction of methanolic methylamine with methanolic P2P is noticeably exothermic.

[Antibody2]

didn't mean to stray from topic but wtf

about the pseudonitrosite way, how would you go from the nitroalkene to the amine ? Beaker's 2CH way ? It needs fucked THF and Pd/C (homemade didn't work), and I never got his impressive yields (80>%), but a 65 %. Anyway it could be a good alternative.

Sunlight, what i meant was using the reduction i posted for TMA a year ago, using NaBH4 to go alkene >> alkane à la Beaker then Al/Hg to the amine. It works just fine for MDA as well, yeilds are similar.

No Pd/C and if a chemist has dry dropping funnel (or patience) they don't need the THF either, drop the nitropropene directly into IPA

"All those memories lost like rain..."

[Grouch]

Another 'off topic':

Using NaCNBH3 with MeNH2 gas in MeOH has way high yields too.  I used no drying agents and no pH adjustment other than one initial adjustment at the beginning with GAA.  I didn't even meausure the MeNH2 very accurately.  It was somewhere in the neighborhood of a 4x molar excess.