The Vespiary

The Hive => Serious Chemistry => Topic started by: mottaman420 on April 03, 2002, 01:56:00 AM

Title: Catalytic hydrogenation of MDP2P/Nitromethane
Post by: mottaman420 on April 03, 2002, 01:56:00 AM
When doing a catalytic hydrogenation of MDP2P/Methylamine to MDMA can one use nitromethane as the methylamine source? Has anyone tried this? How would you go about doing this? What kind of yields can be expected from such an endevor? Should i have posted this in the newbee forum? 8)  Feel free to flame if i fcked up. But hey at least i try.

_.-==''SupaTokaBuDsMoka''==-._
'''''''GonnaGetHighTillIDie'''''''
Title: I don't understand
Post by: Moriarty on April 03, 2002, 03:34:00 AM
Catalytic hydrogenation is a concept for saturation, generally double bonded carbons, olefins.  What could that possibly have to do with methylamine or nitromethane?  It would just seem to me like this idea would negate the methylamine from ever forming MDMA out of MDP2P.  Wouldn't you get 3,4-Methylenedioxyphenyl-2-propanol and unreacted methylamine?  I'm not trying to flame, I'm just curious.

Who wants to play cops and dope fiends?
Title: H2/cat fro reductive amination
Post by: Rhodium on April 03, 2002, 07:15:00 PM
Not true. See my page for examples of catalytic hydrogenation as a means for reductive amination.

I do not know of any trials with this system using nitromethane as the amine source. However, KrZ has done it in a two-step reaction, where he first reduced nitromethane to methylamine in a bomb, then added ketone and reduced. If it is not on my page, then it must be in the archives here.

Title: Using Rh/C
Post by: Moriarty on April 04, 2002, 12:43:00 AM
"A solution of 49.8 g (0.3 mole) of 3,4-dimethoxybenzaldehyde in 150 ml of 95% ethyl alcohol containing 20 ml of 29% aqueous ammonia (0.33 mole) and 25 g (0.3 mole) of ammonium acetate was hydrogenated at room temperature and 3 atm in the presence of 9.0 g of 5% rhodium on carbon.  Uptake of hydrogen was complete in about 3 hr.  After removal of catalyst, the filtrate and washings were concentrated and the residue distilled.  A 64% yield of 3,4-dimethoxybenzylamine, bp 118-120 (1.5 mm), was obtained."  Catalytic Hydrogenation in Organic Synthesis, Morris Freifelder, p. 92, 93, 1978.

I only mention this because this particular synth recognized the superiority of Rh/C over that of Pd/C, getting 64% with Rh/C and 55% with Pd/C.  Unknown if this would be true for all ketone and aldehyde hydrogenations.  I believe Pd/C of preferred due to fact that the addition of Rhodium on a carbon support is said to be dangerous.  Also, most catalytic hydrogenations I've read involved extreme reaction environments, like several atmospheres of pressure.  Any thoughts on different catalysts?

Yields I have read about for the reduction of non-aromatic nitro groups have been bad and, as it would seem, less favorable than aldehydes and ketones and taking longer periods of time.  I believe that this might mean the use of Nitromethane would be a bad idea, allowing MDP2P to form stable products before nitromethane had even begun a conversion.  My knowlegde here is very little, so not much emphasis should be placed on this assumption.  However, NO2 groups were reduced to NH2 in all the catalytic hydrogenation reductions mentioned in pages 31-36 of the above mentioned reference.

Who wants to play cops and dope fiends?
Title: I was considering something else
Post by: mottaman420 on April 04, 2002, 09:03:00 AM
In my dream (literally) I considered using 150 ml ketone with 120 ml nitromethane and 110 ml Methanol and 1 grams Adam's Catalyst.  :P

_.-==''SupaTokaBuDsMoka''==-._
'''''''GonnaGetHighTillIDie'''''''
Title: catalytic hydrogenation
Post by: Ritter on April 04, 2002, 03:59:00 PM
Mottoman:

What kind of yields did you "theoretically" get from that quoted rxn?  Its very easy to specifically reduce  CH3NO2 in the presence of ketone without reducing the carbonyl if catalyst loading is kept on the low side, temp is kept at room temp or less and pressure is not allowed to go above 25PSI.  Different inorganic salts can be added to the rxn. to modify the catalyst to make it more selective towards the imine rather than the ketone.  An example is Fe2SO4 or sodium acetate.  These modifiers don't turn the catalyst into a specific targeting majic bullet, they simply slow  the attack on carbonyls.  However, there are modifiers available which cause the catalyst to develop an extremely high affinity for nitro and imine groups, virtually leaving carbonyls untouched.  KrZ posted the patent for these unique catalysts and if memory serves correctly, they are composed of simple ordinary Pd/C or Pt/C treated with DMSO and/or hydrazine. (

http://gb.espacenet.com (http://gb.espacenet.com)

)

Using standard Adams catalyst as you state in the reaction will work somewhat, however if you are just throwing everything into the bomb and hydrogenating, I know you never yielded more than 50g product (thats a generous educated guess) using 1gram PtO2.  The problem is  that such a small amount of catalyst will become poisoned fairly rapidly.  When the MeNO2/ketone mixture is pressurized w/ H2, the majority of the 2 mols of nitromethane will rapidly reduce  to methylamine.  As the methylamine forms,  it will start to condense with the ketone presenting yet another mole of reducible material (Imine).  One gram of PtO2 will  stop working after 1-1.5 mols of substrate is reduced due to poisoning.  A way around this is to use more PtO2, however you risk reducing the ketone to the propanol with more catalyst.

Yields will be MUCH higher if an ethanolic solution of MeNO2/EtOH is reduced first and  liquids are decanted off into another Parr bottle.  Ketone is SLOWLY added to the bottle of methylamine and an additional gram of PtO2 is added.  The imine reduction is carried out at about 50PSI and takes about 3 hours at room temp.   The yield will be very high- in the %80 range.
Title: Literally
Post by: mottaman420 on April 05, 2002, 04:44:00 AM
In my post when i said "in my dream (literally)" i really meant in my dream. I have never tried such a thing but was wandering if it could work. In an experiment posted by Labtop he used the following formula and their are many similar to it:
1800 ml MDP2P
1200 ml Methanol
1200 ml (1080g) anhydrous liquid MeNH2 (bp -6°C!)
24 g Platinum(IV)oxide (Adam's Catalyst)

I was just wandering if you could just substitute nitromethane in the methylmine's place so that this type of reaction would be available to those who can't get anyhydrous liquid MeNH2 so easily. Assuming that this worked, I was wandering if you could expect similair yields to the ~90% that was supposedly gotten in these type of reactions by various people. If it were indeed true that such a high yield could be gotten that way, than it would seem that many peoples lives would have been much improved. All I'm saying is that if you can substitute it in the Almagation of Al/Hg than why not in the catalytic blah blah blah. I guess i was just hoping that i would have inspired someone to go out and try and hopefully develop a new way for making drugs. I think it would be really great if my contribution to the world in cohesion with someone else would be to make a new way of cooking drugs.

_.-==''SupaTokaBuDsMoka''==-._
'''''''GonnaGetHighTillIDie'''''''
Title: l-PAC
Post by: Antoncho on April 05, 2002, 01:55:00 PM
Cat. hydrogenation of l-PAC and methylamine in ether w/Reney Ni catalyst was the original way for producing ephedrine.

I believe, in another patent they use aq. solutions (???)


Antoncho
Title: Water
Post by: Sunlight on April 05, 2002, 06:52:00 PM
Reduction  of nitromethane produces water, and someone told that the catalytic hydrogenation of MDP2P with emthylamine didn't work with aqueous methylamine, I think it's in Rhodium's page. Anyway youd make a smalll test, small workup to see how it works.
Title: aq. methylamine
Post by: Ritter on April 06, 2002, 03:01:00 AM
Kitty,

Just last night I read an article by Freifelder in which he hydrogenated a mixture of 30%aq. methylamine (.5mols),  P2P(.5mol) and enough ethanol to make the soln homogenous (I think about 150ml).  1.5grams PtO2 was added and hydrogenated at 50psi to yield 90% methamphetamine.  This proves water has no appreciable effect on formation of methyl imines.  I spent the past half hour looking for that article for you, I can't believe I cant find it.  If you really want the citation, let me know and I'll tear my house apart till I find it.  The details I reported in this post are a perfect duplicate of the reference though.  Freifelder is the master of catalytic hydrogenation of phenylacetones.  Over the years I have probably seen about 50 different reductive aminations of phenylacetone published by his group.

Not to mention SWIM gets 85% yields of MDE using 70%aq. ethylamine, so water definetely isn't a problem.
Title: Aqueous methylamine ala Freifelder.
Post by: terbium on April 06, 2002, 11:44:00 PM

Post 182995 (missing)

(terbium: "Re: Silica gel mesh size conversion(s)...", Chemistry Discourse)
Title: What should be done?
Post by: mottaman420 on April 07, 2002, 03:58:00 AM
So what would the ideal ratios of the reactents be in such a reaction. What is the least amount of Adam's catalyst that could be used without suffering to much on the yields?
Also how do you mesure volumes in a canister full of gas (ie if you had to add liquid methylamine to a hydrogentaion than how would you measure out the amount your putting in if trying to avoid freezing temperatures?)

_.-==''SupaTokaBuDsMoka''==-._
'''''''GonnaGetHighTillIDie'''''''
Title: catalyst
Post by: flipper on April 22, 2002, 04:29:00 PM
Ritter wrote:


.  KrZ posted the patent for these unique catalysts and if memory serves correctly, they are composed of simple ordinary Pd/C or Pt/C treated with DMSO and/or hydrazine.




See this Thread

Post 299856 (https://www.thevespiary.org/talk/index.php?topic=6275.msg29985600#msg29985600)

(flipper: "What SWIM wanna make with it", Chemicals & Equipment) and

Post 300160 (https://www.thevespiary.org/talk/index.php?topic=6275.msg30016000#msg30016000)

(flipper: "another question", Chemicals & Equipment)
and

Post 174784 (https://www.thevespiary.org/talk/index.php?topic=12231.msg17478400#msg17478400)

(KrZ: "Sulfided Platinum Catalysts", Novel Discourse)
and

Post 174918 (https://www.thevespiary.org/talk/index.php?topic=12231.msg17491800#msg17491800)

(KrZ: "Re: Sulfided Platinum Catalysts", Novel Discourse)


US patent 3941717 Alias DE 2150220 and GB 1397584
US patent 5498585

PtO2 who needs it. Too expensive. The catalyst described in patent 5498585 is propably better and cheaper. 



You've gotta love me.
Title: Strange conclusion.
Post by: terbium on April 22, 2002, 09:20:00 PM
PtO2 who needs it. Too expensive. The catalyst described in patent 5498585 is propably better and cheaper.
Isn't that patent describing a platinum on carbon catalyst? So how is that significantly cheaper, or better? 
Title: methylamine HCl
Post by: Organikum on April 22, 2002, 10:09:00 PM


the british patent

GB 365 535

describes the reductive amination of L-PAC which should be similar to P2P with methylamine HCl in alcoholic and aqueous solution. Nickel is the catalyst used, yields don´t know, the speak of "good yields" whatever thus maybe.
But, no methylamine gas ever needed, the product of ammmoniumchloride and formaldehyde or hexamine can be used as is. Wouldn´t that be a step in the right direction? No more sibirean family gasing? ;)


Ah baikal, but the smell....
ORGY
Title: Well
Post by: flipper on April 22, 2002, 10:54:00 PM

Isn't that patent describing a platinum on carbon catalyst? So how is that significantly cheaper, or better? 




I assume it is. Let's compare. 100 grams of the catalyst in the patent where i'm talking about contains 3 grams of Platinum. Molar mass of PtO2 weights 227.078.  85.91% of That weight is Platinum. Molar weight of Platinum is 195.08 g/mol And that is 85,91% of the weight of the PtO2, So of 100 grams of PtO2 85.91% is Platinum. What is Cheaper A catalyst containing 3 grams of Platinum or a catalyst containing 85,91 grams of Platinum. That alot of money. I think the price of Platinum these days is something around 150 Dollars/gram.
Then the patent's tell that the yields are better the selectivity is improved and that the reaction time is reduced.
God I only hear good things about this catalyst. I also wanna say that SWIM have not yet xperience with it but he is very impatient to trie it.


You've gotta love me.
Title: Specious and irelevant
Post by: terbium on April 23, 2002, 02:19:00 AM
How much of a precious metal based catalyst to use in a process is determined by the precious metal content. If a procedure calls for 20 grams of 5% platinum on carbon then instead one might use 10 grams of 10% platinum on carbon or 1.2 grams of platinum oxide.


Then the patent's tell that the yields are better the selectivity is improved and that the reaction time is reduced.
God I only hear good things about this catalyst.

And you believe everything that you read in a patent. Well, golly gee, you are a trusting soul!
Title: surprise Mr Terbium and flipper!
Post by: Organikum on April 23, 2002, 06:20:00 AM
surprisingly the link Mr Terbium provided answers this little dispute. This proofs that Terbium links are always worth a read and for everybody too. ;)


and hydrogenated at room temperature and 3 atm of pressure with 1.4 g of platinum oxide



and then


It is possible to substitue 20 g of 5% platinum on carbon.




I am no artist of handheld calculators like flipper, but it is obvious that his way to calculate is not perfectly thought to the end :) .

The relation is 1,4g Pt oxide to 20g Pt/c 5%.

Mr flipper please do the calculation of netto Pt amounts,
but sorry Mr Terbium I see already now that the needed netto amount of Pt is less with Pt/C than with Adams catalyst.
I read the patents on sulphidized catalysts and I agree this should be worth a try but mainly because of reusability. The needed amount of Pt should equal usual Pt/C. Also I had a look at Matthey´s and Adams catalyst seems not to be considered the best choice nowadays, just because of not providing enough surface. But perhaps this is a question of personal taste as I met a chemist lately who told me he would never use anything else then Pt on asbestos. Aha I thought.

flipper the results please!


now I will do some ziatype in my photostudio to relax
ORGY

Title: Only advantage may be selectivity.
Post by: terbium on April 23, 2002, 05:07:00 PM
but sorry Mr Terbium I see already now that the needed netto amount of Pt is less with Pt/C than with Adams catalyst.
I didn't say otherwise. What I said was that flipper's reasoning - that 1 gram of 3% platinum on carbon catalyst is equivalent to 1 gram of Adams' catalysts - is incorrect.
 
I read the patents on sulphidized catalysts and I agree this should be worth a try but mainly because of reusability.
Other Pt/C catalysts can also be reused. I thought that the "advantage" of the sulphided catalysts was supposed to be selectivity. If they truly show selectivity for imine over ketone then it might be possible to use them to good advantage for the production of products such as MDA. On the other hand, for products such as MDMA, where catalytic hydrogenation using PtO2 or plain Pt/C already give yields approaching 100%, there would seem to be little or no advantage.

Also I had a look at Matthey´s and Adams catalyst seems not to be considered the best choice nowadays, just because of not providing enough surface.
Again, I don't believe that I said otherwise. If one is running an industrial process, producing low value product, where cost of catalyst is paramount, then Pt/C will probably provide some advantage due to reducued Pt requirement. You may find, for example, that 0.8 gram of platinum as 10% Pt/C will do the job of 1 gram of platinum as PtO2.
Title: Terbium sir my lord This is what you sad on ...
Post by: flipper on April 23, 2002, 06:44:00 PM
Terbium sir my lord

This is what you sad on February 23 of 2001

Post 174951 (https://www.thevespiary.org/talk/index.php?topic=12231.msg17495100#msg17495100)

(terbium: "Re: Sulfided Platinum Catalysts", Novel Discourse)


Lots of insanely high yielding reductive aminations.

But you can get the same yields from plain PtO or Pt/C without bothering to sulfide the catalyst.

And this is what the lord of Hydrogen Krz answered.

Post 174965 (https://www.thevespiary.org/talk/index.php?topic=12231.msg17496500#msg17496500)

(KrZ: "Re: Sulfided Platinum Catalysts", Novel Discourse)


Not like this you can't.  Look at LabTops PtO4 writeup.  He describes usage of a very expensive quantity of the catalyst. You could use close to the same weight of 3% sulfided catalyst and get equal if not better results.  You also must control the pressure to help reduction of imines in preference to ketones, which can cost time.  The sulfided catalysts (1) Require less catalyst per quantity of ketone (2) Provide better yields (admittedly only slightly since the current techniques are already high yielding) and (3) Are poisoned much more slowly and therefore remain active longer.  If you are going to be using a platinum catalyst for this sort of procedure, you might as well go through with such a simple procedure to improve it so much.

Also, this extreme selectivity finally opens up the possibility of a one-pot nitro->amine, amine+ketone->imine->amine catalytic hydrogenation reaction.  Previously, side reactions while the amine was forming would have made this impossible, but now it is well in reach! And not a intensely nonscaleable Al/Hg type reaction, just dumped all your goodies together and blast it.


Too make a point:



He describes usage of a very expensive quantity of the catalyst. You could use close to the same weight of 3% sulfided catalyst and get equal if not better results.




If one can Hydrogenate with a Sulfided 3% Pt/C catalyst and get better yields and use almost the same quantity of catalyst as when you're using PtO2. Well I think my choice is quickly maked. I bet you that A 3% Pt/C catalyst is alot cheaper then PtO2.


flipper the results please!




SWIM likes to give them but SWIM has some money problems so he first have to work a little bit. I mean a real job with a salary. Maybe I will be rich sometime and maybe thanks too this catalyst.  8)


You've gotta love me.
Title: What KrZ said.
Post by: terbium on April 24, 2002, 07:40:00 AM

Too make a point:


Referring to:
--------------------------------------------------------------------------------


He describes usage of a very expensive quantity of the catalyst. You could use close to the same weight of 3% sulfided catalyst and get equal if not better results.



--------------------------------------------------------------------------------

If one can Hydrogenate with a Sulfided 3% Pt/C catalyst and get better yields and use almost the same quantity of catalyst as when you're using PtO2.


And I say that this is not true.  As I have said before, you will need the same quantity of platinum. The carbon is just an inert carrier and the sulphiding is just a poison to make the catalyst less reactive toward some functional groups.



Title: catalysts vs catalysts
Post by: Organikum on April 26, 2002, 06:07:00 AM

If allowed I sum up:

- there is an advantage in using Pt on C instead Adams catalyst.I do not know why a reduction of 20% of platinum, or more is regarded as insignificant by Terbium. As I lost my platimum mine at Monte Carlo Casino last year I regard this as good information.

- as I read nothing else Adams Catalyst is not reuseable at all, Pt on C can be reused. How often will depend on how clean the used materials are. (right?). The patents state that prolonged usability is the advantage of sulphidized Pt on C. Matthey backs this information up so I would say it should be true. This point is important for bees having not the equipment for a easy recycling/workup of platinum, not everybody is used to aqua regia, what is not very easy to get (yes I know, UTFSE, but in terms of "low profile" it is better if you don´t need it). For the process of sulphidizing is very easy I, just I for myself, would give it a try when preparing Pt/C.

- There is a certain chance that reactions may be run with a far less amount of sulphidized catalyst compared to Pt/C. AFAIK a catalyst is loosing activity very fast at the start of a reaction. This is because of poisoning. Prepoisoned catalysts are said to have an higher activity level over all. Also it should be possible to optimize other parameters like pressure and temperature as "overreduction" will not take place now so soon if at all.

Without tweaking pressure and/or temperature, modified catalysts are probably nonsense in most reactions. With tweaking.......

I would be glad if Terbium could disclose if Platinum black has other advantages over Pt/C or other substrate based catalysts. Where is the secret, for you always name this?


and a little OT:
Is it possible to hydrogenate an aminoalcohol to the correspondending amine  in EtOH or MeOH as solvent with Pd or Pt on C as catalyst and H2SO4 added? This was once called the "MasterPlan". A straight yes or no is all I want. I can offer a few "maybe" in exchange, some handcrafted some bulk. A non fake answer is prefered.




sticks for beating dead cows anyone?
no? OK just asked...
ORGY
Title: -=]DUB[=-
Post by: mottaman420 on April 26, 2002, 11:37:00 PM
Adam's catayyst can be reused. And once it is eventually worn out it can be reworked. Like you said "as i read nothing else"<---Maybe you should try reading something else.

Blue Horses + Red Donkeys = Purple Mules
Title: Re: As I have said before, you will need the same ...
Post by: zooligan on April 27, 2002, 02:08:00 AM

As I have said before, you will need the same quantity of platinum. The carbon is just an inert carrier and the sulphiding is just a poison to make the catalyst less reactive toward some functional groups.




I want to preface this with the disclaimer that I don't know shit about real chemistry.  I'm guessing, but I bet that you need less precious metal-on-some carrier catalyst (by metal weight) than PtO2 (by metal weight) because the exposed surface area of the metal-on-carrier is greater with less metal weight than with the PtO2 catalyst.

z


"No one can build his security upon the nobleness of another person." -- Willa Cather
Title: reuse of adams catalyst
Post by: Organikum on April 27, 2002, 10:40:00 PM

mottaman, in the hurry you forgot to point me out the readings on this. I am always interested in valid information on catalyst preparation, reuseability, poisoning  and more. Yes I USFSE but exept in the "large scale production doc" on Rhodiums page I found nothing on this. Might Terbium perhaps share knowledge as he seems to know adams catalyst very well?

If Mr mottaman was only ranting without knowing he may be so kind and suck my dick.
ORGY
Title: Catalysts
Post by: mottaman420 on April 27, 2002, 11:32:00 PM
The word catalyst should trigger a few thoughts like it doesn't react but helps another reaction to proceed. Think of the RP meth cookup. You still have the RP at the end. The catalyst can be taken out after the reaction is done. Slight poisining of the catalyst does occur. But you can rework it back into the shit you want. Heres the formula for reworking worn out adam's catalyst. followed by a formula to make adam's catalyst (you said you were intrested in formation recipes).

"Catalysts

Prepare one of the following catalysts, as appropriate to your chosen hydrogenation reaction, following consultation with a Demonstrator:--


Adam's Catalyst3

In a fume cupboard, dissolve chloroplatinic acid (H2PtCl6.6H2O, 0.10 g) in water (ca. 0.5 ml) in a porcelain crucible (3-4 cm diameter). Add sodium nitrate (1 g) and evaporate the mixture to dryness, over a low flame, with continuous stirring. Turn the Bunsen burner full on and stir the contents of the crucible vigorously until the mass has melted completely and the initial decomposition has subsided. Keep the bottom of the crucible at a dull red heat for a further 30 min. (too strong a heat decomposes the oxide to the metal). Allow the crucible to cool and wash the contents into a 250 ml. beaker with hot water from a wash bottle. Filter off the brown platinum oxide with a small ('Hirsch') funnel (Whatman paper No. 541) and wash the oxide with hot water (about 200 ml) until the washings are free from nitrate ion. Dry the catalyst over calcium chloride in a vacuum desiccator.




Palladium Black4

Heat a mixture of palladium chloride (0.50 g) and water (100 ml) to 80deg.C and carefully neutralise the suspension, to wide-range indicator paper, with 20% sodium hydroxide solution (if the end point is overshot, palladium hydroxide precipitates). Add 2.6% formic acid (2.5 ml) and, after about 2 min. make the solution strongly alkaline with 20% sodium hydroxide solution (5 ml). Add more of the formic acid (5 ml) and make sure that the solution is still alkaline. Heat the mixture on a steam bath for 2 hours. Filter off the precipitate with a small ('Hirsch') funnel (Whatman filter paper No. 541), wash it free from alkali and dry it over calcium chloride in a vacuum desiccator.


5% Palladised Charcoal5

Heat decolourising charcoal (7.5 g) on a steam bath for 2-3 hours with conc. hydrochloric acid (5 ml) and water (150 ml). Wash the charcoal by decantation with hot water until free of acid, filter it off, and dry it in an oven at <100deg.C.

Warm palladium chloride (0.5 g) in conc. hydrochloric acid (0.75 ml) and water (5 ml) on the steam bath for ~ 20 min. Add the solution to AnalaR sodium acetate (17.5 g) in water (50 ml) contained in a hydrogenation flask. Introduce the purified charcoal (5.8 g) and hydrogenate the mixture until no more hydrogen is absorbed (~ 2 h). The hydrogenation procedure is described below. Collect the catalyst on a 7 cm Buchner filter (3 thicknesses of Whatman No. 1 filter paper), wash it with water (5 x 100 ml) and drain it on the filter with suction. Dry the catalyst over fresh silica gel in a vacuum desiccator and store it in a tight stoppered bottle.


Lindlar's Catalyst (5% Pd on CaCO3, poisoned with Pb)6

Stir calcium carbonate (precipitated, light; 1.1 g) in water (10 ml) in a flask which is fitted with a thermometer and mounted on a magnetic stirrer/hotplate. Whilst continuing the stirring, add palladium chloride (90 mg) to the suspension and after 5 min., raise the temperature to 80deg.C for a further 10 min. Cool the mixture and transfer it to a hydrogenation flask, using ~ 10 ml of water for rinsing. Hydrogenate the mixture until hydrogen absorption (10-20 ml) is complete (ca. 15 min); the hydrogenation procedure is described below. Collect the reduced catalyst on a small 'Hirsch' funnel (Whatman filter paper No. 1) and wash the catalyst with distilled water (20 ml). Add the damp catalyst to distilled water (10 ml) in a flask on the magnetic stirrer/hotplate. Switch on the stirrer, add a 5% (w/v) solution of AnalaR lead acetate in water (2 ml) and, after 10 min., raise the temperature to 90deg.C for 40 min. During this time, add distilled water, as necessary, to compensate for evaporation losses. Cool the mixture, collect the catalyst on Whatman No. 1 paper in a small 'Hirsch' funnel and wash the catalyst with distilled water (total, ~ 50 ml). Transfer the catalyst to a clean, tared, specimen tube and dry the catalyst in a pistol at 40deg.C to constant weight (~ 1-3 h). Crush the dry catalyst to a powder with a clean spatula or glass rod and stopper and label the tube (catalyst yield: 0.9-1 g)."
Heres the reworking one:
1) dissolve worn out catalyst in aqua regia under a fume hood. This turns platinum into chloroplatinic acid.
2) boil away mixture.
3)Add hydrochloric acid and evaporate until the residue is free of nitrates
4) Now that you have your chloroplatinic acid follow the above mentioned steps to convert it into your adam's catalyst.

This website might help you understand a little about hydrogenations.

http://www.chem.ucalgary.ca/courses/351/Carey/Ch09/ch9-6.html (http://www.chem.ucalgary.ca/courses/351/Carey/Ch09/ch9-6.html)



Oh and a big fuck you to organikum cause he would like me to suck his dick (sorry i'm not gay buddy)



Blue Horses + Red Donkeys = Purple Mules
Title: rP not catalyst.
Post by: terbium on April 28, 2002, 01:15:00 AM
The word catalyst should trigger a few thoughts like it doesn't react but helps another reaction to proceed. Think of the RP meth cookup. You still have the RP at the end. The catalyst can be taken out after the reaction is done.

Phosphorus is not a catalyst in the rP/I reduction of ephedrine. In that reaction the phosphorus is consumed. There is recovery of rP in the end because it is used in large excess.
Title: REUSING!!!! Pt catalysts
Post by: mottaman420 on April 29, 2002, 06:30:00 AM
The following excerpts are takin from

https://www.thevespiary.org/rhodium/Rhodium/chemistry/mdma.catalytic.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/mdma.catalytic.html)



From the first section: "The mix was filtered once with vacuum to recover the catalyst (which was rinsed with MeOH), and again through celite to remove the brackish color present due to remaining catalyst particles."

From the 2nd section: "Re-use your PtOIV"
From the third section: "He should use a Buchner filter on a vacuum bottle with Whatman no 401 filtering paper, he expect that other type of filters makes this filtering of the Platinum powder a endless job"
All these readily hint to the fact that you can reuse your catalysts. They make more sense if you read em in context though.
:P  :P  :P

Blue Horses + Red Donkeys = Purple Mules
Title: ???
Post by: mottaman420 on April 29, 2002, 11:45:00 PM
Would anhydrous magneisum sulfate react with nitromethane, Pt(IV)oxide, methanol, hydrogen or any combination of while under pressure during a catalytic hydrogenation.??
If it wouldn't than couldn't you do a catalytic hyrdogenation with 40% aqueous methylamine or nitromethane without worrying about producing the tertiary amine associated with high water levels. If magnesium sulfate wouldn't work than could you use some other agent to absorb the water without interfering with the reaction.

Blue Horses + Red Donkeys = Purple Mules
Title: don`t know about catalysts but Al/Hg
Post by: SPISSHAK on May 23, 2002, 04:57:00 PM
You can use salt (NaCl) in Al/Hg reductions to bind water I don`t know about catalyst systems though?
Title: NaCl doesn't bind water.
Post by: Rhodium on May 23, 2002, 05:48:00 PM
NaCl doesn't bind water.
Title: Tertiary amine?
Post by: terbium on May 23, 2002, 07:34:00 PM
If it wouldn't than couldn't you do a catalytic hyrdogenation with 40% aqueous methylamine or nitromethane without worrying about producing the tertiary amine associated with high water levels.
I have never heard of this. Can you provide a reference or more details?