Author Topic: Basic Leuckart OTC  (Read 12164 times)

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  • Guest
Basic Leuckart OTC
« on: January 19, 2002, 04:38:00 PM »
Why on Earth do it the hard way?
65% Formic acid: tanning shops or bee-keepers supply shops (cheap btw).

Dump into this 65% formic acid 250 gram/liter zeolites type 3A, aka molecular sieves, mesh 4-8, swirl occasionally while let stand a few hours, decant and repeat with fresh Type 3A molecular sieves , until you have reached the density of 90% formic acid, needed in the next procedure. (Check d20°C with balance and 100ml exact measureing flask)
Yeah, fuck, what's the d20°C of 90% formic acid? Look it up :  ?,?? g/ml!
Formic acid 96%, HCO2H:
mp=8.2-8.4° , bp=100-101° , d=1.220
Check on the label if "they" included any other shit than water! Then you have to distill or precipitate that shit out first.

'I ever got a can of the 4-8 mesh, little balls of rock about 1/8" = 3 mm, diameter. They absorb about 20% of their weight of water over the course of a few hours. Not expensive either : US$ 2.05 a pound in 10 lb quantities, and reusable indefinitely. You drive off the water under a broiler for an hour.
Take f.e. a liter of 95% ethanol, throw in 250g of the stuff, swirl occasionally, filter out the next day through a strainer, and voila! Anhydrous 99%++ ethanol pure; anhydrous that is, with less than 1% water content. The purest ethanol that can be produced by ordinary distillation is only 95.6% pure, the rest being water. More common for home distillation is 170-190 proof -- 85-95% pure.'

  This gives quite some info on molecular sieves!

Ehh, what more.., ahhh, Formamide! Make it in situ :


J. Am. Chem. Soc. 75, 921-925 (1953)


The most simplistic Leuckart Reaction :

Take a three-necked, 2 Liter RB-flask, fit it with :
A dropping funnel, a thermometer reaching to 1 cm from the bottom, a Friedrich condenser arranged for downward distillation (so not reflux), and a magnetic stirbar .
Add 315 ml of 28% aqueous ammonia (NH4OH) to the 2 L RB-flask.
Stir this solution and add dropwise 264 ml of 90% formic acid.
Then remove the stirbar and heat the solution gradually over a 2 to 3 hour period to 160°C, the temperature being regulated so that fairly rapid distillation takes place. (throw distillate away).
==>>After cooling back to 110°C, 164 g. (1.0 mol) of o-methoxyphenylacetone is added and the mixture heated at 160-170°C for 5 hours. (1.0 mol of MDP2P = 178.8 g, so use that instead!)
At the end of the first 2 hours period, the upper layer of the distillate is returned to the reaction flask.
After standing overnight the homogenous solution is heated 2 hours more.<<==
It is then cooled back to 70°C , 360 ml of concentrated hydrochloric acid (31-33%) is added dropwise and the mixture heated for 6 hours under reflux and allowed to stand overnight.
The suspension is diluted with 600 ml of water and extracted several times with benzene (or toluene, or whatever suites you).
The aqueous layer is basified, extracted with benzene ( or etc.) and the residue from the benzene distilled under an atmosphere of nitrogen; b.p. 118-122 deg C at 11mm, yield 95 g. (58%).
(This yield is for o-methoxyphenylacetone, not for MDP2P! No need for nitrogen atmosphere either!
You will find out yourself what the yield is for MDA...)

According to rumors in the Hive corridors, the procedure between the ==>> <<== could be done at a more moderate temperature, say 135 to 140°C, where a just noticeable CO2 bubbling in the reactionmix is the threshhold for the max temperature allowed, and for an extended period of up to 3 days. This is said to increase yields into the 70% figures... LT/

Ahh, can't resist, an Extra:

Separating Ethanol From Water Via Differential Miscibility.

The differential miscibility of castor oil in ethanol and water can be exploited to separate ethanol from water.
Burning the separated ethanol would produce more energy than would be consumed in the separation process. Very energy saving!
In contrast, the separation of a small amount of ethanol (actually an ethanol/water solution poor in ethanol) from water by the conventional process of distillation requires more energy than can be produced by burning the resulting distillate. Very energy consuming!

Castor oil would be added to an ethanol/water solution. The ethanol would mix freely with castor oil, which is insoluble in water. The resulting ethanol/castor-oil phase, which would contain less than 1 percent water, would collect as the top layer, the bottom layer being the remainder of the ethanol/water solution somewhat depleted in ethanol. Heating this two-layer mixture to a temperature slightly below the boiling temperature of ethanol (78.5 deg C) would cause the partial pressure of ethanol above the top layer to be much greater than the partial pressure of either castor oil or water. This vapor-phase ethanol could be condensed in a relatively pure state.

Although heating an isolated ethanol/water solution like that in the bottom layer would normally raise the vapor pressure of both ethanol and water above the solution, this would not be the case in the presence of the top castor-oil/ethanol layer for the following reasons: The amount of water that could dissolve in the top castor-oil/ethanol layer would increase only slightly upon heating. On the other hand, ethanol could readily cross the interface between the two layers and enter the top layer. As long as the total mix was kept at a temperature below the boiling temperature of ethanol (thereby preventing agitation of the layers by boiling), the diffusion of water through the castor-oil/ethanol phase would be inhibited.

In an alternative version of this concept, the upper castor-oil/ethanol layer would be skimmed off and heated to obtain the ethanol. Once the ethanol was driven off, the castor oil could be returned to an ethanol/water solution to dissolve more ethanol to repeat the process. This concept could readily lend itself to a continuous process. Substances other than castor oil (one of its components perhaps, or another substance) could be used in this process or to extract other compounds from other mixtures by using this upper-of-two-phases vaporization technique.

Do not start a factory based on this, I will start that first,  :P .



  • Guest
Re: Basic Leuckart OTC
« Reply #1 on: January 20, 2002, 12:14:00 AM »
Why trying to concentrate 65 or whatever% of formic with zeolithes? I don't think that will work anyway, the mol sieve won't selectively absorb the water and leave the HCOOH alone.
If you can get such formic acid then you can convert it into ammonium formate or formamide directly.

And I don't buy that castor oil EtOH separation either. Sure, EtOH will mix with castor oil. But that doesn't mean that this can be used to extract the EtOH from an aqueous solution. Just distill the EtOH, the azeotrope with water contains 94% EtOH. I'd rather use CaO to concentrate it any further, and get rid of the last water traces with a mol sieve than dumping shitloads of mol sieve in.


  • Guest
Re: Basic Leuckart OTC
« Reply #2 on: January 20, 2002, 12:56:00 AM »
If you can get such formic acid then you can convert it into ammonium formate or formamide directly.

Uh, yeah, in the procedure in the first post you are adding the formic acid to 28% aqueous ammonia so it does not matter if the formic acid is 65% or 90%.

As for the castor oil method for producing dry ethanol, I have found a Russian website with many schemes of the same ilk. Here is one cute one:

and here we have a demonstration of a personal anti-gravity device:

here is the home page:


  • Guest
Re: Basic Leuckart OTC
« Reply #3 on: January 20, 2002, 04:01:00 AM »
Molecular sieves and zeolithes don't sound very OTC to me !

Converting to ammonium formate seems better, or just buy ammonium formate (descaler) very OTC !

One day I'll understand everything !


  • Guest
Re: Basic Leuckart OTC
« Reply #4 on: January 20, 2002, 01:00:00 PM »
"Molecular sieves and zeolithes don't sound very OTC" come on, fancy names. A zeolite is a type of clay structure, one example of which is bentonite. Ceramic supplies count as OTC, since you don't have to pretend or explain. Heating powdered clay makes it give off water, from interlaminar spaces where large molecules can't go. Formic acid, though, isn't a very large molecule. Using a crude dewatered clay for a rough drying agent would cost you some of it, talk about quick and dirty.

A type of bentonite, which is a zeolite, is the cheapest product over the cheapest counter of the cheapest bargain store, namely generic cat litter. But that stuff could give ions like sodium, unless you wash and dry repeatedly before baking it. So if you're unwilling to deal with separating clay by sedimentation as a drying process, there's another kind of kitty litter which may bee used instead. That's the kind made of silica gel beads. They do pretty good; I reheat them after purchase. They decrepitate with audible snaps if they get real wet.

"Molecular sieve" is a description of a mesh size, not composition.

If the amount of water in formic acid does become a problem, do distill. If it's still a problem, then use a drying agent. If purity is then a problem, redistill. That's the "best" way, though most time-consuming.

turning science fact into <<science fiction>>


  • Guest
Re: Basic Leuckart OTC
« Reply #5 on: January 20, 2002, 01:50:00 PM »
Zeolithes, bentonites, clay, cat litter and mol sieves aren't the same thing!!!


  • Guest
Re: Basic Leuckart OTC
« Reply #6 on: January 21, 2002, 07:11:00 PM »
>the azeotrope with water contains 94% EtOH.



  • Guest
Re: Basic Leuckart OTC
« Reply #7 on: January 21, 2002, 07:16:00 PM »
Smartass.  ;)

Live long and Prosper.


  • Guest
concentrating carboxylic acids
« Reply #8 on: January 21, 2002, 07:25:00 PM »
Here's a list of patents for concentrating carboxylic acids, such as acetic and formic.

Patent US1867943

Patent US3677023

Patent US1826302

Patent US1839932

Patent US1854568

Patent US1861841

Patent US1696432


  • Guest
Re: Basic Leuckart OTC
« Reply #9 on: January 21, 2002, 08:43:00 PM »
Hey, smartasses, it's 95.6 % max, and I can proof that. You both didn't read it in my post the first, second and third time?

As said before, a fine researcher follows a written procedure first to the letter, and when he succeeds, THEN he's gonna try to outsmart the publishers on details, ain't it so? And is prolly
gonna stumble over some NOT expected strange effects when he tries to change it.

Terbium, goodfella, that was a HIGHLY interesting link (antigravity). I followed a few others there, and stumbled over this one:

  , so please download the full book(only 300+KB)

and be amazed!
I am going to concentrate a bit more on "behind iron curtain" search engines, I seem to have missed quite a lot of the fun lately.
Btw, I was moved by the poetic expressions of the lately deceased enthomologist, who loved his insect gardens so much. He was a nice person, so to read. I hope he succeeded to preserve his gardens even after his death with publishing those "flightplans", greedy russian technocrats will hopefully fall for it, and give him the benefit of the doubt, and keep their fingers off his insect save havens. LT/



  • Guest
Re: Basic Leuckart OTC
« Reply #10 on: January 21, 2002, 08:55:00 PM »
Also see this patent 2011790.  You can easily make sodium formate from dilute formic acid.

Post 223390 (missing)

(PolytheneSam: "Re: MDP2P rdxn with formamide", Newbee Forum)


  • Guest
Re: Basic Leuckart OTC
« Reply #11 on: January 22, 2002, 01:15:00 AM »
I'd never heard that about castor oil, nor does it sound very efficient.  However, I have read an article on the separation of ethanol from water using sulfur, which makes a lot more sense.  all three forms of sulfur are insoluble in water, but all three forms of sulfur are soluble in alcohol to varying degrees.  I'm still not sure how they plan on getting the sulfur back out of the alcohol after extraction though.  I hope they're not planning on burning the alcohol with the sulfur still in it! :o   No telling how acidic that would make the rain, as if it's not bad enough.

If Pacman had influenced us, we'd run around dark rooms eating pills and listen to repetitive music


  • Guest
questions on the Leukart
« Reply #12 on: March 21, 2002, 09:12:00 AM »
a Friedrich condenser arranged for downward distillation
Would a simple distillation setup work? Aren't we just removing the water? Or could someone explain how this type of condenser works?

After cooling back to 110°C, 164 g. (1.0 mol) of o-methoxyphenylacetone is added and the mixture heated at 160-170°C for 5 hours. At the end of the first 2 hours period, the upper layer of the distillate is returned to the reaction flask.

So this is still a distillation, correct? After 2 hrs, the distillate is returned to the reaction flask. Let it distill back over again?

Sorry for the silly questions, just trying to visualize what this would look like in action.


  • Guest
Condenser Q
« Reply #13 on: March 21, 2002, 11:36:00 AM »
A simple distillation setup is fine. It is a normal distillartion, and the distillate will be ketone and water. Only the ketone is transferred back to the distillation flask.


  • Guest
« Reply #14 on: March 21, 2002, 04:19:00 PM »
If one were using MDP2P there should be very little ketone that comes over, if any, correct?


  • Guest
Place subject line here.
« Reply #15 on: March 21, 2002, 05:44:00 PM »
Correct. Little or no MDP2P should distill over.