Urea is located @ chem stores right?  I would like to have completely OTC.  How easy is pool acid, cyanuric acid, and lye.  Really give me a break it wouldn't even involve anything other than addition....

I bought urea a couple times from a plant nursery.  I've been using it in a fertilizer mixture that I make up which also includes triple superphosphate (monocalcium phosphate), potassium sulfate, Epson salts, and a mixture containing trace elements comprising boric acid, copper sulfate, iron sulfate, manganese sulfate, sodium molybdate and zinc sulfate. 

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

Hey all
Here is i think the lowdown on the steroisomerism shit.

I have the ref rhodium posted.
And he is correct about dimethyl being the compound with a n methyl group as ephedrine.  How ever the steroisomerism should be (R,S) with ephedrine and (R,R) with pseudo, I THINK.

However I would make very sure before tasteing this compound.  Because the (S,S)dimethyl aminorex can easily produce fatal seziures, the article says!!!  Would pseudoephedrine, which is (1R,2R)-(-)-Pseudoephedrine, produce the (S,S)dimethyl aminorex or (R,R)dimethyl aminorex?

In other words I would maybe only try this with ephedrine since it is (1R,2S)-(-)-Ephedrine and would almost surely produce a (R,S)dimethyl aminorex.

Anyone a sterochemisty wizz?
left handed or right handed and all that bullshit

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Do Your Part To Win The War

There are two types of instant one time use cold packs. One contains ammonium nitrate and the the other contains urea. The brand containing urea can be found at a popular chain store. Hint: bulls eye.

I've found on Beilstein these US Patents, but  I cannot open it on uspto.gov:

3278382 and 3161650

They can be opened using the patent search engine at the bottom of

https://www.thevespiary.org/rhodium/Rhodium/chemistry/index.html

So swim made NaOCN from 41g Urea and 102g Na2CO3. Now I have this solid white mass and I'mm not sure how to go about purificaation.

Any beez have ideas? I'll do a complete writeup from NaOCN through the Carbamyl Ephedrine to 3,4-DimethylAminorex with all detail / observations included. I also have some interresting ideas on using PseudoPPA.HCL (d-NorPseudoEphedrine) to make ICE (4-MA) with the same process.

Hold thumbs on this one beez, and thanks to Rhodium for this goldmine novel idea.

So is the PPA found in OTC Sinutab etc. d-PPA, the one that will give 4-MA with the KCNO method?

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N-carbamyl-(±)-pseudoephedrine

5g (±)-Pseudoephedrine hydrochloride (25 mmol) in 50ml methanol was added a solution of 2g potassium cyanate (KOCN, 25 mmol) in 150ml methanol, and the solution was heated under reflux for one hour. Potassium chloride was filtered off and the filtrate evaporated to dryness. The residue was recrystallized from 20ml of ethyl acetate to give 2.2g of the substituted urea as white plates, mp 140-141°C.

(±)-trans-3,4-Dimethylaminorex HCl

A solution of N-carbamyl-(±)-pseudoephedrine (1.65g, 75 mmol) in 24ml water and 15ml 2N HCl was refluxed for three hours, when the clear solution was cooled the (±)-trans-3,4-Dimethylaminorex hydrochloride precipitated. This was purified by basifying the solution, extracting it with benzene (can use any non-polar solvent here), and the solvent evaporated and the freebase converted to the hydrochloride by gassing with dry HCl in ether. Yield 1.9g, 84%, mp 225-229°C.

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Surely if 25mmol pseudephedrine.HCl = 5g, 75mmol N-carbamylpseudoephedrine cannot be 1.65g?

From Purification Of Laboratory Chemicals, 4th Ed:

Sodium Cyanate, NaOCN, mp 550°C. Colorless needles from ethanol. Solubility is 0.22g per 100g EtOH at 0°C. Soluble in H2O, but can be recrystallized from small volumes of it.

"Urea is located @ chem stores right?  I would like to have completely OTC."

You would like to have completely OTC urea?! 

Honestly! You can't get any more OTC than that! I used to have an old hardbound laboratory manual around here somewhere, circa 1940's, that detailed how to prepare urea from human urine. Unfortunately, I can't find it. I'm sure the laboratory intructors of the time were amused by that experiment. Part of the procedure involved collecting the "first urine of the morning" and boiling it down into a "syrup".

Mr. Smith recommends eating steak or other high protein food before attempting this procedure.

For those who are curious:

Gattermann&Wieland 'Die Praxis des organischen Chemikers' prepare the KOCN by mixing Kaliumhexacyanoferrat (Fe(CN)6K4) and Kaliumbichromate and dropping spoon by spoon this mixture on a hot iron plate. The KCNO is extracted with boiling alcohol from the resulting rxn mix.

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Carpe Diem

Uemura: Is that from the 1850's?

So in the final step should one use 1.65g or 25mmol (5.16g) or 75mmol (15.47g) of N-carbamyl-(±)-pseudoephedrine?

Am I correct in thinking the commonly available OTC form of PPA is d-pseudophenylpropanolamine, the one which by the KCNO method would turn into trans-4-methylaminorex?

Many thankx,
IudexK

The original reference reads 1.56g, 0.075 mole. (seems that I made a mistake in the typing, but it still doesn't make sense).
If 0.0075 moles (7.5 mmol) were used, then the N-carbamoylephedrine would weigh in at 1.56g.

So I typed the weight wrong, and they lost a zero on the number of moles they used.

What is the full stereoconfiguration of OTC PPA? The d-PPA designation does not tell us which way the oxygen points. But only trans-4-methylaminorex can be formed using the cyanate route, if the wrong isomer is used, you will get an amide rather than an amine.

Thankx, I will try and find out what OTC PPA's stereoconfiguration is... but the easiest way would probably bee to try it.

Would [1RS,2RS]-phenylpropanolamine used in the KCNO method give equal parts cis/trans-4-MA?

Racemic norpseudoephedrine would give an inactive amide (removable by an acid/base extraction), and racemic norephedrine would give racemic trans-4-MAR. [1RS,2RS]-phenylpropanolamine (an equimolar mixture of the above two) would give half racemic trans-4-MAR and half the inactive amide.

It does not seem to be possible to create the less active cis-4-MAR using the cyanate route.

Edited to fit the changed stereochemistry in the first post in this thread.

ok, last question, I promise  

Do you happen to know the stereoconfiguration of the PPA produced by this synth?:

https://www.thevespiary.org/rhodium/Rhodium/chemistry/ppa.html

Many thankx,
IudexK

It will produce the "double racemic" [1RS,2RS]-phenylpropanolamine.

It's available from my local hardware store. Walk in, buy urea in 25 kg tubs. Ain't NOTHING more OTC than that. Except that it's not over the counter, cause there isn't even a counter, it's OTS - off the shelf!

W101 should listen to his own advice, yes?
In South Africa Urea is in hardware stores.
I don't imagine it makes much difference in this case, but one should practise what one preaches.


Got a surprise there when I saw the melting point - I remembered my ref. saying something about 300 something - went and looked it up, and it said >300 C - I need a better ref. manual