March 30, 2006 topic "Propylhexedrine" from wd.ws:

Wizard X:

Propylhexedrine is used in nasal decongestants. Merck 7873, pg1248, 11th edition. Since
ephedrine is becoming increasingly difficult to extract from tablets, an alternative is
propylhexedrine. No HI/P reduction is needed, just Dehydrogenation.

Propylhexedrine physical properties. Oily liquid, density at 25 deg C is 0.85 gr/ml,
refractive index at 20 deg C is 1.4600, Bp at 760mm is 205 deg C; Bp at 20mm is
92-93 deg C. very slightly soluble in water. miscible with alcohols, ether and chloroform.
Absorbs Co2 from air (1).

Dehydrogenation with pd/c or pt/c catalysts

Add 0.02 moles of the propylhexadrine freebase compound, 0.3 grams of a 10-30%
pd/c or pt/c is used, in mesitylene, b.p. 165 deg C or cymene, b.p. 177 deg C, with a
constant stream of N2 gas to sweep the extracted (removed) H2 gas(1). Reflux for 3
hours, Cool to room temperature and filter off the dehydrogenation pd/c or pt/c, wash
with fresh solvent. Strip the combined solvents with distillation or better still a rotary
evaporator to obtain the aromatic compounds, Methamphetamine freebase. Alternatively,
you can gas the solvent/methamphetamine freebase solution with dry Hcl to obtain
crystal precipitation.

(1) CO2 can not be used as it combines with propylhexedrine and methamphetamine
freebase. If it does, it will form a carboxylate salt with the amine, known as ICE.

P.S. does anyone know why all the posts at the wd forums ended at around November 2010?
I have seen no new activity there...what has happened?

Please Wizard X...any idea where this may have gone wrong? it was a dismal failure. I searched for weeks looking for any papers that would verify it could work, and found quite a bit which I will post later, I read them each probably 50 times over and over...but am at a  loss.

Call the researcher a nitwit mad scientist as it was performed even knowing that no real
world evidence that it actually works was found, beforehand scoured all of the net and the old hive in search of any shred of evidence that anyone had success....nothing other than the following quote above, however, did find substantiating papers that showed it "could work" in theory....hopes were high, and after several weeks of preparation this was researched:

1300mg of pure white propylhexadrine hcl was based by adding to 50ml saturated lye solution, shook well for 1/2 hour, extracted with 30ml of cymene, poured off into a sep funnel, seperated off the 27ml solvent layer, as 3ml always get caught up in a slight 1/4" emulsion that is disposed along with the lye water.

p.s. can give details later if anyone is interested in how to quickly turn 1 inhaler into 250mg of pure white propylhexedrine everytime, getting rid of the other oils returns a perfect 250mg hcl each time, pure enough for eating with pristine effects, no acetone cleaning necessary.

 The 27ml solvent layer containing the propyhexadrine freebase was then washed x 3 times with 9ml of distilled water, dried, and put into a 50ml round bottom flask with magnetic stir bar, and for 15 minutes a stream of nitrogen was passed thru the flask with stirring to drive off any oxygen gasses to eliminate bubbling/foaming from the flask during the reaction.

quick test: A 1ml sample was taken from the 27ml solvent and dissolved into hcl acidified water and evaporated to get an estimation test of how much propylhexadrine was now in the solvent solution, 30mg was recovered from the 1ml test, indicating that approximately 810mg of propylhexadrine hcl had successfully been freebased into the solvent.

the reaction: to the 50ml round bottom flask holding the 27ml of solvent/propylhexadrine freebase
with stirbar was added 200mg of 5% pd/c unreduced and activated. It was brought to the cymene boiling point under reflux (177 degree C) for approximately 3 hours. At first when the reflux temp was reached (approximately 350 degree F) a reflux drop of 1 drop about every 5 seconds was seen, this was seen for a good 1/2 hour, the temp was raised slightly, than about 10 minutes later, an unusual effect was seen, the boiling solvent seemed to become super hot, as most of it shot up about 1/2 the way up the condenser, the heat was turned off and brushless motor fan applied to grape seed oil filled heating liquid to quickly cool the stuff a bit to insure the liquid would not do this again.....After this initial sort of scare, the heat was brought back up, but even when brought to over 350 degree F, could observe no reflux any longer, no drop ever 5 seconds or even 10 seconds, no reflux drops at all, completely be-wieldering.

The whole time the reflux was performed under a stream of nitrogen (about 1 bubble every second coming out of the mineral oil from the bubbler....as a T-fitting was used over the condenser, one end connected to the n2 regulator, and the other end connected to a tube submerged about 1" down in a bubbler.)

Anyhow, after 3 hours of heating, the flask contents were filtered thru a coffee filter into a 1/2 pint size jar, the pd/c remained on top the filter, and 1/2 hour later there was a clear layer of cymene sitting at the bottom of the jar. It was acidifed with hcl water, evaporated, and as expected 800mg of some kind of substance was returned, it was cleaned with cold dry acetone, sampled, but got no effects, the taste was a bit different from propylhexedrine hcl (which has a tangy bitter like weird taste)...this was not as bitter, as if the amine had been destroyed on the molecule or something else had happened to it....after no effects were gotten from 10mg, then 50mg was tried every hour, until all 800mg was consumed over the course of several hours, no effects at all....researcher's conclusion was that the reaction had somehow destroyed the molecule's integrety.

Research was attempted twice more with smaller amounts, and each time, the weird "boiling up" of the flask contents was seen approximately 1/2 hour or so after it was maintaining a normal 1 drop every 3 to 5 second or so reflux....what was going on? was the pd/c being poisoned by the amine structure of the propylhexadrine freebase? Is an amine protector needed? If so, what would that be? At a complete loss to explain.

Researcher thought about performing the reaction in xylene instead to see if maybe the lower boiling temp of the xylene would solve the boiling up problem, but pretty much gave up the whole project...and chalked it up to being crazy enough to follow a procedure that had never been attempted as far as know by any dreamer ever.

P.S. does anyone know why all the posts at the wd forums ended at around November 2010?
I have seen no new activity there...what has happened?

The last post on that topic is from earlier this year:

https://the-collective.ws/forum/index.php?topic=22437.msg160594#msg160594

but it wasn't encouraging    It's not as simple as many have hoped    The end results from the effort applied 

Researcher still had 500mg of propylhexadrine freebase dissolved into clean and dry 20ml solvent, in theory would this work? give the reflux of 100mg of it (4ml of solvent) with 600mcg (3 selenium health pills, each pill contains 200 mcg selenium) and bring it up to reflux temp for a while, then cool it down, filter off, and acidify the solvent with muriatic water, evap, clean, and see if there are any effects. Interesting papers and theory with the selenium. Many Chinese people are know to take in an average of 3,000mg of selenium a day in areas of the country where the soil is high in this mineral which is a very potent antioxidant. came across many a paper that uses selenium for dehydrogenation. in all of this research, and allready owned the supplement.

All about selenium:
hxxp://customers.hbci.com/~wenonah/hydro/sebacker.htm

Thanks Wizard X! Read the paper linked to at AAAS, however, it is a bit above my understanding. I do appreciate the link and will continue to read it until I do understand it. There is nothing mentioned in the paper about sweeping with nitrogen gas, which I was hoping to find...are you referring to the sweeping of N2 gas that is used in photocatalytic fluidized bed reactors? See 3.1 in this link:
"Photocatalytic Oxidative dehydrogenation of cyclohexane to benzene" uses a stream of N2 gas.
(see page 3 which is section 3.1)
https://docs.google.com/viewer?a=v&q=cache:it3vLm6rhhYJ:downloads.hindawi.com/journals/ijp/2009/709365.pdf+photocatalytic+oxidative+dehydrogenation+of+cyclohexane+to+benzene+3.1&hl=en&gl=us&pid=bl&srcid=ADGEESiAkaubkHBWB6fBT9XZfaZ7WIabfMmTCez8kH49b2DAASb0ReXKxh51Lef8ru8tcHvuphgjKK6gczbS-XF8m3_fs5v22n_VRzY2FGT4H11Tr0qFcJ3O_XpIGbSnzXGpwlyyiikZ&sig=AHIEtbSaAptiuFA8IVOrGqsUyyCsdwL9Yg

The middle paper found below (by shere luck and diligence) over the few months of past research seem to indicate that simple refluxing of cyclohexene type molecules (1 step removed from cyclohexane) in 5% pd/c in either xylene or cymene will result in the phenol after a few hours, even as much as over 63% in as little as 15 minutes in cymene, but the same results take at least 3 hours in xylene....so what am I missing here? The 1st paper indicates that pulling off that 1st hydrogen from the cyclohexane on Pt surfaces is the slowest step in the process, but after that, the other 5 hydrogens start to fall off a lot quicker....at the temperature range of 260F--440F the formed benzene desorbs from the metal surface as the boiling solvent is in gas phase. Xylene boils at around 282F, so it can work (but it will take longer as the 2nd paper shows), and cymene boils at around 350F, so it works, and takes much less time.

Could be wrong, but I believe what was happening in the researcher's experiments, was that all
6 hydrogens were being pulled off from the cylohexane ring in due time (during the 1st 45 minutes using cymene, however at that point a very fast boiling up out of the refluxing solution was seen, as if the benzene ring was then being dehydrogenated to surface carbon & even more hydrogen, leading to the unwanted destruction of the benzene ring, had the research been stopped before that point, perhaps the phenol would have been obtained in decent yields.

In the 1st of the 3 experiments, when the reaction was immediately stopped right when that boiling over occurred and over 50% of the reaction contents were lost, something resulted that appeared active to the researcher, alblight in small qty due to loosing too much solvent overflowing the condenser tube and exiting the nitrogen exhaust tube into the mineral oiled filled bubbler. The taste of the substance after pd/c filtering and acidification/cleaning was very different from propylhexadrine hcl, and seemed active at only 5mg....perhaps had the researcher used xylene instead of cymene, this boiling over phenomena at the 45 minute period could have been avoided which definately seems to cause irreversable destruction of the molecule as it is dehydrogenated past phenol into surface carbon? Which is what may have happened during the 3rd experiment, when after the boiling up 1/2 up of the condenser was seen, the heat was turned off, but then was turned back on and allowed to heat at very high temp for some 2 hours beyong that violent boiling over...this resulted in 810mg of completely inactive stuff that lacked a bitter taste as if that phenol ring was indeed decomposed to carbon.

Thermochemistry of the selective dehydrogenation of cyclohexane to benzene on Pt surfaces by Bruce E. Koel, David A. Blank, Emily A. Carter. 1997 Department of Chemistry, University of Southern California, Los Angeles, CA. Journal of Molecular
Catalysis A: Chemical 131 (1998) 39--53.

https://docs.google.com/viewer?a=v&q=cache:cYCzN9YNchgJ:www.princeton.edu/mae/people/faculty/carter/ecdocs/EAC-88.pdf+&hl=en&gl=us&pid=bl&srcid=ADGEESj6i5LV2IHFej4g0n87YW4K8Ff-arowhaGsBkuzPS_iTHpNJ89iIebgQqS8VwQSElaPUSN0ZiL21MLjA5ESpGE4DehlZshZSygigBFVIEYbfYTkIF80yDHOvft_cF8XabKU-8ZW&sig=AHIEtbS4qi2Ze6Tb-DMvWSz4rTNjPYFN_Q
hxxps://docs.google.com/viewer?a=v&q=cache:cYCzN9YNchgJ:www.princeton.edu/mae/people/faculty/carter/ecdocs/EAC-88.pdf+&hl=en&gl=us&pid=bl&srcid=ADGEESj6i5LV2IHFej4g0n87YW4K8Ff-arowhaGsBkuzPS_iTHpNJ89iIebgQqS8VwQSElaPUSN0ZiL21MLjA5ESpGE4DehlZshZSygigBFVIEYbfYTkIF80yDHOvft_cF8XabKU-8ZW&sig=AHIEtbS4qi2Ze6Tb-DMvWSz4rTNjPYFN_Q

Note in the paper above which can be found in its entirety (free) on the web, that once the cyclohexane is converted to benzene on the Pt or Pd surface (occurs at low temps around 82 degree F), that benzene desorption is then required to form the gas phase product. Benzene is formed on the surface at temperatures near 300 K (Kelvin) which is 82 degree F. Further heating causes a fraction of the benzene formed to desorb from the surface at 400--500 Kelvin (260 to 440 degree F). (see page 41) and the remaining benzene to decompose to hydrogen and adsorbed carbon. Xylene can still work as the BP of xylene is 138 degree C (281 degree F)....cymene has boiling point of 350 degree F, and mesitylene BP is 329 degree F.

AS this paper points out, cyclohexane is adsorbed with molecular plane parallel to the surface
with C3V symmetry, probably in a chair configuration with three axial H atoms projecting
toward the surface, forming hydrogen bonds. Adsorption leads to a broad, low frequency C-H
stretching band due to extensive "softening" of the axial C-H bonds. The surface coverage in
the monolayer is between 0.13 to 0.21 monolayer (ML). upon heating, some  cyclohexane desorbs, but most of it (68%) converts to adsorbed benzene which decomposes to hydrogen
and adsorbed carbon.

Here is a good picture of the cyclohexane molecule, you can see the three axial H atoms that
get popped off on each side. cyclohexane is C6H12, benzene is C6H6. propylhexadrine is
C10H21N, now minus the 6 axial hydrogens that get popped off and you have C10H15N which is methamphetamine.

http://en.wikipedia.org/wiki/Cyclohexane
http://en.wikipedia.org/wiki/Benzene
http://en.wikipedia.org/wiki/Propylhexedrine
---------------------------

Aromatization Studies. IV. Palladium dehydrogenation of Arylcyclohexenones to Phenols. E. C. Horning, J. Am. Chem. Soc., 1947, 69 (6), pp 1359-1361 June 1947.

http://pubs.acs.org/doi/abs/10.1021/ja01198a035
hxxp://pubs.acs.org/doi/abs/10.1021/ja01198a035

In this paper (see the 1st page which is free) you see the drawing at the bottom left of the cyclohexen-1-one molecule which is dehydrogenated to phenol  using 5% pd/c catalysts....the rate of conversion was 63% in only 15 minutes in  boiling cymene, or 82% in 2 hours....52% was converted using a lower boiling solvent like ethylbenzene in only 2 hours Xylene was found to work as well for the conversion in the paper.
----------------------------
United States Patent, Keith Gladwin, Chesterfield, England, Catalytic Dehydrogenation, 4,254,288....Mar. 3, 1981.

http://www.docstoc.com/docs/31488326/Catalytic-Dehydrogenation---Patent-4254288#viewer-area
hxxp://www.docstoc.com/docs/31488326/Catalytic-Dehydrogenation---Patent-4254288#viewer-area

In this patent, you see that the reaction system was also refluxed, at the temperatures stated in the table, while a stream of nitrogen was also passed through the system, just as Wizard X states. The dehydrogenation is carried out in a solvent under reflux. The pd/c catalyst is prefered to be up to 5% by weight. Shown is the dehydrogenation of 2-alkoxycyclohexanol  to produce an orthoalkoxyphenol. 2-isopropoxycyclohexanol (316g), diphenyl (316g) and pd/c catalyst (10.6g) were added to  a dehyrogenator together with sodium carbonate (3.16g) and diphenyl suphide (equiv. to 24 ppm S). (these 2 last ingredients are where the patent comes in to improve yields a bit). The content of the reactor were brought to reflux and maintained at reflux for 24 hours. Over this period, 144 liters of hydrogen and off gases are evolved. The reaction mixture was filtered to remove the solid material . The yield of o-isopropoxyphenol was 81% based upon 2-isopropoxycyclohexanol.

Reference Information


Method in which cyclohexane is removed of its hydrogen atoms and double bonds are introduced to the ring.....java

Reference Information



Aromatization Studies. IV. Palladium Dehydrogenation of Arylcyclohexenones to Phenols
E. C. Horning , M. G. Horning
J. Am. Chem. Soc.
1947, 69 (6), pp 1359–1361
DOI: 10.1021/ja01198a035



Palladium-Catalyzed Aerobic Dehydrogenation of Substituted
Cyclohexanones to Phenols
Yusuke Izawa et al.
Science
333, 209 (2011);
DOI: 10.1126/science.1204183

The way this is done in the factory, is that they take actual methamphetamine and then hydrogenate it, the reverse process is catalytic dehydrogenation.

Cyclohexane (C6H12) adsorbs onto the metal surface at low temps (<=120 degree Kelvin) then dehydrogenates completely to form benzene (C6H6) on the metal surface at 300 degree Kelvin, then benzene desorbs from the metal at temps between 260 and 450 degree F while the solvent is refluxing in gas phase. Desorption: http://en.wikipedia.org/wiki/Desorption

Have a gut feeling that the reaction will work using refluxing xylene to return somewhere around 50% yield at 3 hours. The cyclohexene was converted to the corresponding phenol in the 1947 paper by Horning in 52% yield in 2 hours using a solvent that boils at even 12 degrees lower than xylene!, The cyclohexane (2 extra more axial hydrogens than cyclohexene) should convert to the corresponding phenol with an extra hour (3 hours) to yield around 50%. At 350 degree F using refluxing cymene the reaction progressed accordingly, but then when temp raised to 375 degree F, some sort of unwanted reaction took place, causing the unwanted boiling up of the solvent up out of the condenser tube (faster than an al/hg) and out the nitrogen exhaust line into the bubbler oil. The very high heat seemed to destruct the molecule at about the 45 to 50 minute point once the reflux was seen to begin.

When this occurs, and if the solvent is then cooled down for 10 minutes, but then taken back up to reflux temp for 2 hours, then cooled down, if you look at the solvent, you will see that the pd/c has been dispersed into millions of tiny fragments which float all through the solvents, and it takes a good 45 minutes to filter it out over a simple coffee filter placed over a jar, (done outside, as the pd may have hydrogen dissolved into it, which can be flammable when it does dry) whereas this "fine super dispersion" of particles does not take place when refluxed at lower temp, and it is way faster to filter.

But does anyone know why back in 1947, that Horning did not bother to use a "stream of nitrogen" or nitrogen atmosphere to remove the extracted hydrogen? It was not a concern whatsoever in the paper, he just states to "reflux vigorously" however, if you read the patent paper by Gladwen, he used a "stream of nitrogen" to remove the 144 liters of hydrogen and other off gases that were evolved during the refluxing.

Still don't know whether a nitrogen atmosphere with bubbler is correct, or if a nitrogen stream is supposed to be dropped down INTO the refluxing solvent via a long glass pipette down the condenser? which is the correct method?

Swim doesn't even know what methamphetamine tastes like, as has only tried DIDREX in dreams, happened to find a 12 year old prescription bottle for it with 90 pills, each of the pills converts to methamphetamine in the liver...had alot of fun with those pills and to got alot of work done over the months...so that explains the whole story behind all the dreaming. Feel like I'm talking to myself, so peace out for now, will stop post hoaring the forum, just that this method seems all to easy and according to the papers it should work....just don't use too high a heat, something unwanted happens that totally destroys the molecule.

A nickel and copper alloy is said to dehydrogenate cyclohexane fairly well, I'll dig up the ref if I can but heads up, it was a moderately old thing. This is the gist of it: http://www.amphilsoc.org/sites/default/files/Sinfelt.pdf