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NS29
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| Joined: 19 Sep 2005 |
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336.56 Points
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reduction of pfed with sodium sulfite, iodine and dh2o?
Mon Sep 19, 2005 7:54 pm |
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i've stumbled over the following post by ahgreich in the rhodium archive:
https://www.synthetikal.com/hiveboard/crystal/000271993.html
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Whoo doggies. Success.
He's now feeling the product of a successful reduction of Pfed fb with
sodium sulfite,
iodine,
and dh20.
Phan-fucking tastique!!
No RP. Had to happen. It's all in the metaphysics, the incantations, and a few dead chickens.
Swim'll speak in equivalencies instead of empirical weights, as he don't have a scale.
in a 250 ml rbf, he placed the following, in order:
3 teaspoons of very dry, very clean pfeb fb xtals ( slightly over 3gms) pre-sifted with 6 teaspoons of sodium sulfite.
1 1/2 teaspoons of dh20 on the top of the dry pile at bottom of flask (enough that the whole pile was wet enough to sling about, yet not thin - consistency of black-strap molasses.
He then 'staged' around 11g I in a small beaker, readied his punch baloon: dumped in the I, snaped the balloon on top, taped the hell out of it, and waited.
20 sec or so, exotherm began without addition of ANY external heat source.
pile got nasty purple, bubbling. NO SMOKE. He watched it for about 10 minutes until the I had been reacted (no longer a purple nasty mass, but light pale beige-ish. No smoke yet, no balloon movement inflation. bubbling subsided.
On to the stove he went, appling liberal heat such that the punch balloon was the size of a large grapefruit. The flask contents evolved a brilliant yellow. Removed from heat, watched some clear liquid run down flask neck, waited for flask to cool (15 minutes or so) - the pasty flask contents became white as it cooled. At room temp, was nearly as white as sodium sulfite. All the while, he was fondling the flask, rolling it, jiggling it, keeping the liquid moving.
Back to the stove, heat until boil and balloon inflated, contents turned back yellow! Removal from heat and close observation revealed that the contents where getting shiny-like.
Did this routine 3 times, each time yellow when hot, white when cool.
last time cool, removed balloon, no smoke, didn't stick his nose in for a smell - strange really, no strong smells to speak of during the whole party. The strong-ass punchy was secured on the flask before any reaction started, retaining all gas.
workup - 2 tolly washes of post rxn b4 basing into 3rd shot of tolly with
Ass-load of NaOH (he reckons to polarity-crawl back through the aq NaSO4 (from the sodium sulfate rxn product).
Should have washed the tolly with base a few more times, however, as he is sailing through the bioassay:
HCL/dH20 xtylzation - exceptional. Da real medicine, all nice like.
long legs, slight whitish residue (see prior sentence about washing NP better prior to HCL/H20).
RP/I smells not noticable during the endeavor.
Why did it succeed? He thinks:
1. JUST enough dH20 to have high enough concentration of aqHI as HI was generated yet not so much that ALL of the HI would have a place to go as soon as it was made.
3. application of heat meant that the HI concentration in dH20 was affected causing the yellowing. However, the heat facilitated the mobility of the flask contents, at times becoming a true reflux.
Whooeeee. How bout them apples?
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couldn't find any follow ups on that though.. 
Last edited by NS29 on Tue Sep 20, 2005 8:27 pm; edited 1 time in total |
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loki
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re: reduction of pfed with sodium sulfide, iodine and dh2o?
Tue Sep 20, 2005 9:28 am |
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omg!
i have long wondered if there might be other acids that can do it. note that sulphite is also known as sulphurous acid, and the regenerating agent in rp/i2 is phosphorous acid (both of them are reduced acids). i am surprised that there was no sulphurous smell at all from this reaction...
definitely needs to be looked at further, sulphites are easy to get, and widely used as preservatives in the meat industry amongst other things.
it'd be neat if iodine could be removed from the formula too, perhaps, for example, putting zinc dichloride in there instead of iodine.
for some reason i can't find any info on it but there is a chemical called sulphur iodide... if someone can dig up more about it, it might be part of the reaction mechanism. |
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Zombee
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| Joined: 07 Sep 2005 |
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185.80 Points
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re: reduction of pfed with sodium sulfide, iodine and dh2o?
Tue Sep 20, 2005 2:32 pm |
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Or ferrous chloride instead of zinc dichloride.. (was that me?  ) |
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loki
guinea pig
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re: reduction of pfed with sodium sulfide, iodine and dh2o?
Tue Sep 20, 2005 3:03 pm |
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oh nevermind that thing, removing chlorides is not anywhere near as facile as removing iodides. iodine is NOT the hard chemical to get, phosphorus is. i mean, pseudo is a pain but the relative amount of work involved in cleaning it is nothing like dealing with mbrp and it's becoming a major pain in the ass as match manufacturers keep on reducing the amount of red they put in and replacing it with this ugly brown crap.
i am amazed to realise that i actually read that thread before. it's a shame that immediately after a positive report the thread diverged onto the topic of hydrogen sulphide... to my mind this is like talking about ammonium formate and then switching the topic to cyanide. crazy.
i can't believe that there has been no more follow up on this. phosphorus is such nasty shit, if a person absorbs something like 50mg they drop dead and chronic exposure causes necrosis of the jaw... certainly the rp/i2 rxn is not as demonically dangerous and toxic as it is said by the media but still. if i had the choice between a common food additive and a chemical better known for its association with incendiaries and smoke bombs, i know what i'd be choosing.
edit
Something occurs to me also - since sodium sulphite is the reagent, there is no reason i can think of why sodium iodide, and maybe potassium iodide, could be used instead of iodine. a foaf claims that HCl and KI can be substituted for I2 in a rp/i2 reaction, and swim has tried this scheme and indeed hydriodic acid *does* form (possibly due to minimal water content and precipitating sodium chloride putting it out of the reaction). Sulphuric acid would certainly be permissible in this reaction scheme to acidify, i'm not sure about HCl but being that it doesn't readily substitute for OH's, it should be equally usable. one thing though, in that report he talks about using pseudoephedrine freebase, so maybe there is no need to add any acid at all.
If indeed sulphurous acid (a synonym for sulphite) is able to do this reaction, being a cheap reagent using an excess of it would be a guarantee of complete reduction.
It is also possible that sulphite is, similar to phosphite, a dehalogenating agent, which would make it more analogous to hypophosphorous reactions in the sense that HI adds I to E, and H2PO2 reduces E-I to M and HI.
If sulphite can do this reaction, there can definitely be a case made for the idea of isolating the sulphurous acid and using it like phosphorous acid. However if the reagent works as is what's the point.
another random thought: potassium iodide and potassium phosphite could work similarly, and both chemicals are quite OTC.
edit 2:
http://www.newton.dep.anl.gov/askasci/chem03/chem03117.htm
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I2 crystals from the melt: The m.p. of I2 is about 113C. At that temperature it has a
significant vapor pressure so the process has to be carried out in sealed glassware. A
FUME HOOD IS MANDATORY, AS WELL AS SODIUM SULFITE OR SODIUM THIOSULFATE SOLUTION FOR
NEUTRALIZING ANY SPILLS.
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I have not previously seen mention of this before but sodium sulphite is interchangeable with sodium thiosulphate. This means it readily converts iodine to hydriodic acid, which is what sodium thiosulphate does.
i am going to do some intensive research into the uses of sodium sulphite in the literature because this looks very promising.
edit 3
http://www.newton.dep.anl.gov/askasci/chem00/chem00816.htm
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Any reducing agent will form iodide anion from the iodine in solution, and
the solution will become colorless, since the iodide ion is colorless. A
safe and effective reducing agent is sodium sulfite, which is used as a
de-chlorinator in swimming pools, and is available from a swimming pool
supply store. Ascorbic acid (vitamin C) will probably also work, but I have
not tried that.
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http://web.princeton.edu/sites/ehs/artsafety/sec11.htm
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Sodium sulfite is moderately toxic by ingestion or inhalation, causing gastric upset, colic, diarrhea, circulatory problems, and central nervous system depression. It is not appreciably toxic by skin contact. If heated or allowed to stand for a long time in water or acid, it decomposes to produce sulfur dioxide, which is highly irritating by inhalation.
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edit 4:
Oh i just noticed that the topic has a spelling error, it's sulfite, not sulfide. these are two very different chemicals, Na2SO3 vs Na2S
I've been unable to find a great deal of information about sodium sulfite and its reactions but I have determined one thing, that the way it works is two moles of sodium sulfite react with one mole of oxygen or something else which reacts similarly (halides). You can see by looking at the molecular model that it is begging to have oxygen re-attach to it, but at the same time, the cause of its irritating effects on digestion (colic etc) is due to the fact that given time or heat in solution it liberates H2O from its structure and releases sulfur dioxide.
In the reaction under discussion the mechanism i propose is that the halide is attracted to the sulphur atom, and then reacts, withdrawing the hydrogen from the sulphite and leaving behind SO3 which then combines with water to make H2SO4. sulfites are also used to scrub oxygen from water, and theoretically could be used to remove oxygen from air by bubbling air through a solution of sulphites. The mechanism by which it does this is different from the reaction with halides. Halides are attracted to it but cannot bind so they withdraw the hydrogens, whereas oxygen splits adding to two sulphite molecules to form sulphuric acid. The net effect of the different reactions is the same but operates differently -- the reaction with oxygen could happen in anhydrous conditions, whereas the energy barrier for halides doing the same thing without water is much higher, and probably would require quite high temperatures.
In the reaction described at the top of this thread there is two places i can see reactions occurring. One, which is well known can be stated with certainty, the reduction of elemental iodine to hydriodic acid. It is also possible that the sulphite ion can react with iodoephedrine to remove the halide via the same mechanism, the halide is attracted to the sulphur atom, and then reacts by donating the two hydrogens, one each to the halide and the amine substrate. Someone with some handy non-aromatic organic halides could test whether this reaction occurs, benzylic halides would be the perfect test.
The mechanism of sulphite in its reactions with halogens is similar in the mechanism to ascorbic acid which pulls the halide close via the double bonded carbons, the double bond breaks, shifts to the oxygens, liberating the two hydrogens which then bind to the halide, splitting it into two molecules of hydriodic acid. Or some sequence similar in effect.
If anyone can pull up a reference or two to these kinds of reducing agents acting on organic halides would be very useful. (hypo)phosphorous acid, ascorbic acid and sulphites all operate on the same basic principle of pulling the halogen containing compound right in between, convert the two oxygens (temporarily in the case of the phosphorus and sulphur compounds) to double bonded oxygens and liberating two hydrides due to extra charge now present in the centre atoms/pair of atoms (in the case of ascorbic acid) which bind to the molecule being reacted to (oxygen or halides). I can see that ascorbic acid will not be able to react to an organic halide directly, but phosphorous acid can and if this is correct, sulphurous acid should be able to perform the same reaction. I think that hypophosphorous does it somewhat differently actually, it would make the -OH form =O which would involve withdrawing charge from one of the hydrogens, and then the intermediate would react with water to form phosphoric acid. In other words hypophosphorous' reaction is probably different enough to regard it as a slightly different mechanism, however, despite this, in practise phosphorous acid and hypophosphorous behave identically except for the caveat that phosphorous acid is unstable due to it's lack of the double bonded oxygen it more readily withdraws it from the atmosphere or from dissolved oxygen in the solution. (i'd say that phosphorous acid reaction probably would benefit from inert atmosphere to reduce this effect).
edit (again):
sorry for such a long and drawn out post, i am in the process of uncovering the information about why this might work...
I think that if there is no problem with sulphuric acid and hydriodic acid being in the same solution that this reaction will indeed work. The reason why sulphates are a no-no with phosphorous reductions is because phosphorous acids preferentially reduce sulphuric acid over iodine and iodoephedrine. The SO3 formed by the oxidation of sulphite also consumes water, which is an advantage this reaction system has over the phosphorous reaction system. If the reaction only works via the hydriodic acid reducing the ephedrine, then water is produced by the reaction, but the same amount of water would be taken up by the SO3. So, given one has the right ratio of sulphites to water in the reaction, as the reaction proceeds it will not change at all in terms of the total water content... which is another advantage of this reaction system, the formation of water inhibits the action of hydriodic acid. And there is clearly no issue about forming any nasty smelling gases - SO3 is nasty but it would just have to hit humid air to be rendered relatively benign - but i don't think it can the gas outside the solution/slurry because there's water there and thus it never leaves the reaction. |
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loki
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Mon Sep 26, 2005 8:55 pm |
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ok, been thinking more about this, and it occurs to me that maybe bisulfite would be a better choice (and easier to get hehe). the reason i am thinking this is because it is more acidic.
another aspect of sulfite which is worth noting is that the acid, sulfurous it is actually SO2 dissolved in water. i wonder whether one could simply produce iron sulfide and hydrate it to release stinky SO2 gas and bubble that through a solution of KI and pseudoephedrine. this would produce sulfurous acid too.
in the wikipedia entry on sulfurous acid it said that according to analysis it is actually an equilibrium
SO2 + H2O ⇌ HSO3− + H+
only one Na is thus required to tilt the equilibrium in favour of the sulfurous acid. |
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loki
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Tue Sep 27, 2005 10:25 am |
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| ok, in a dream i saw an alchemist throw a bunch of sodium bisulphite and water, about half a teaspoon of bisulphite and a teaspoon of water. the alchemist then added potassium iodate, which he'd learned reacts with bisulphite to produce hydriodic acid. upon addition of dry KIO3 it immediately exothermically reacted and some elemental iodine was formed and vapour went everywhere, a lot of iodine and sulphur dioxide filled the air (the alchemist coughed and complained about his asthma). The solution/slurry turned bright yellow. about a gram of pseudoephedrine freebase was added and the reaction was sealed with a rubber membrane and allowed to heat at about 70 degrees for an hour. the solution was diluted and basified and extracted with hot naptha, and then extracted into dilute HCl solution. the alchemist seemed to rush this process and as such his yield was quite low. however, after ingesting the yield he became quite sure that he had successfully performed some degree of transmutation of the base element into a higher element. The success was not, in his opinion, good enough to be unequivocal but good enough to doubt that he had ingested untransmuted lead. |
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NS29
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| Joined: 19 Sep 2005 |
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336.56 Points
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Tue Sep 27, 2005 1:52 pm |
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hooray! - long live the alchemist!
how much KIO3 did he throw into the mix? |
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loki
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Tue Sep 27, 2005 3:13 pm |
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oh, about 5g.
the alchemist continued with his experiment, he was quite sure he hadn't successfully extracted all of the product (and it should be noted that this would have selectively isolated ephedrine due to pKa) and he wasn't convinced he ran the reaction correctly so he did it again, this time with about 5ml of HCl added. about an hour later he added another teaspoon of bisulphite salts (he used more water the second time and was concerned that it would inhibit the HI reduction, so he figured saturating the solution would help). he then extracted the material by basifying it directly with dry NaOH, extracting it into hot naptha (it got very hot just from the NaOH addition so it was diluted until all solids dissolved and separated) and then it was extracted with HCl and evaporated.
and then i woke up again, DAMMIT... i love it when i have dreams resume when i return to sleep... maybe i will be lucky and the alchemist will continue his story. |
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loki
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Tue Sep 27, 2005 5:11 pm |
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and the dream continued again...
| Quote: |
the alchemist then ended up with a very tiny amount of product which he consumed and was satisfied that it had been transformed. AT LAST, THE WHOLLY GRAIL!
the alchemist cursed the measly amount of precursor he did the experiment with, and the lame workup that he did, but he did a silly dance in celebration of a result which was worth following up.
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...so anyway, the dream was a marginal success, considering the tiny amount of precursor, this was not unexpected. however, the effects he gained from the result were enough to cause minor mydriasis. not a lot, but nothing to sneeze at.
the use of elemental iodine or iodide salts is probably a good idea, as is making the NaHSO3 solution saturated so that there is some solids remaining. under heating the sulphite solution rapidly (well, within an hour or two) lost its yellow tint, but if it was contained at first it pressurised and then it depressurised, and did not lose colour - the bright yellow colour seemed to be an indicator of saturated sulphite solution. the pressure changes in the vessel, which i assume is from the withdrawal of oxygen from the atmosphere inside the reaction vessel by the sulphites, is exactly as expected. iodates were problematic in this reaction because of the way that iodate reduces iodides to elemental iodine.
on a side topic: one of the annoying things about working with iodine from tincture is there is always a bit more I2 you can't get, the stuff that's dissolved in there as elemental mostly doesn't come out, maybe at best one can get half out. the problem is you cannot put a base in there without ending up with iodoform. however, sodium bisulphite would convert the elemental iodine directly to iodide without the iodoform problem. the result would be an acidic solution composed entirely of iodide salts. this would then be able to be converted to the elemental iodine after reducing the alcohol. to nothing. |
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loki
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Tue Sep 27, 2005 6:07 pm |
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now that i am satisfied (in my dreams) that the reaction *can* do the reduction, i think it is appropriate to work out stochiometry.
pfed + 2HI --> MA
I2 + HSO3 [-] + 3H2 O --> 2I[-] + HSO4 [-] + 2H3 O[+]
this means that the molar ratios are thus:
1 mol pfed
1 mol iodine
1 mol sodium bisulphite
3 mol water
this is assuming ideal conditions invoving zero loss of SO2 from the bisulphite (which anyone who has used the chemical would know is inconceivable), so to ensure the reaction completes 2x as much sodium bisulphite will be used, and of course this means twice as much water is needed
165.2346g pfed
253.809g iodine
208.11174g sodium bisulphite
108.0912g water
I think if this ratio is used the reaction will run to completion with full conversion. As for reaction conditions, I am not sure what is ideal. I think probably that running it like a LWR is the way to go, since the LWR reaction mostly depends on HI doing all the reduction, it takes a lot longer. the alchemist ran his second more successful attempt for 4 hours. 8 hours is probably minimum. temperature was about 70 degrees the whole time which seemed to be plenty of temperature but since it was just a dream I am keen to hear opinions on the duration and temperature that it should be done at. |
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NS29
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| Joined: 19 Sep 2005 |
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336.56 Points
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Wed Sep 28, 2005 8:14 pm |
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i would love to try it.. but it's difficult to get sodium bisulfite here :/
it's a food preservative but nobody sells it in quantities under 10kg.
i've learned that it can be produced by passing sulfur dioxide through a solution of sodium carbonate.. but i couldn't find any further infos about the process
any substitutes?
oh.. and sweet dreams to you loki! =D |
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loki
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Wed Sep 28, 2005 10:48 pm |
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SO2 passed through sodium carbonate solution is how its made. SO2 is made by pyrolising elemental sulphur (available at garden shops at 99.9% purity). why would you want 10kg of it anyway. the brew shops sell it in 500g tubs here, au$5
sometimes it is called 'sodium metabisulphite' for reasons unknown to me, except maybe it is referring to the 120 degree angles between the oxygen atoms on sulphurous acid and bisulphite having only one of them with a sodium on it. |
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NS29
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Re: re: reduction of pfed with sodium sulfite, iodine and dh
Thu Sep 29, 2005 1:16 pm |
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| loki wrote: |
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sometimes it is called 'sodium metabisulphite'
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but sodium metabisulphite is sodium disulfite (Na2S2O5, E223) right?
where sodium bisulfite is (NaHSO3, E222).. *puzzled*
sodium metabisulphite or german "natriummetabisulfit" would be much easier to get |
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loki
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Thu Sep 29, 2005 3:26 pm |
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sodium (meta)bisulphite is highly acidic because it only has one sodium per sulphite ion. sodium sulphite is disodium sulphite, similar to how you have sodium bicarbonate which has one carbonate ion per sodium ion, and sodium carbonate has two sodium ions per carbonate ion.
sodium bisulphite is NaHSO3 whereas sodium sulphite is Na2SO3 (note the absence of the hydrogen). it is possible to call it sodium hydrogensulphite the same way that you call sodium bicarbonate sodium hydrogencarbonate.
Sodium bisulfite [7631-90-5]
Synonyms: Monosodium sulfite; Sodium acid sulfite; Sodium bisulfite; Sodium hydrogen sulfite; Hydrogen sulfite sodium; Sodium sulfite (NaHSO3); Sulfurous acid, monosodium salt;
sodium bisulphite structure
Sodium sulfite [7757-83-7]
Synonyms: Disodium sulfite; Sodium sulfite; Sodium sulfite (Na2SO3); sulfurous acid, sodium salt (1:2); sulftech; Sulfurous acid, disodium salt;
sodium sulphite structure |
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joe_aldehyde
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re: reduction of pfed with sodium sulfite, iodine and dh2o?
Fri Sep 30, 2005 1:28 pm |
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| metabisulfite dissociates into HSO3- ions when put into water, since it's virtually the "anhydride" of sulphurous acid. |
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