wakatutu
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CuSO4, Bromides, Neurotoxic Gas (LONG POST)
Well, this post is not going to be a fun one. Putting it in beginnings because I'm obviously not very advanced in my understanding of chemistry.
(somehow existing on the level of an idiot despite thinking I'm quite clever)
I have performed the hydrolysis of bromovanillin lots of times before. Usually nothing has gone wrong and 5-hydroxyvanillin has been isolated in
various levels of purity. This time, which I will consider my absolute last time trying this particular reaction, I doubled the scale relative to
each previous reaction, and this resulted in a prolonged extraction effort. Instead of taking 2 days from start to finish, it took a total of 4 days.
And during the final boil-off of remaining residual solvent, a very nasty gas was produced which caused serious health effects resulting in two ER
visits, lots of blood work, and a soon-to-start series of sessions with a neurologist. I have hypothesized that the most likely culprit is bromine,
causing dysfunction of the thyroid and thus causing the neurological symptoms, but it's possible that an organic compound with severe neurotoxic
properties was produced. I really don't know. So I'm posting my lab notes and hoping that someone can help identify the toxic substance I
was exposed to.
Here are the lab notes, somewhat abbreviated to assist in readability.
80g NaOH in 500ml H2O
4g CuSO4 in 80ml H2O
Reaction mixture is heated to 75C
66.6g Bromovanillin added with manual stirring. 300ml water is added to assist in dissolution, bringing total volume of reaction mixture to 900ml.
It appears to boil at 91C. Strange.
Heat is held at 96-104C for 24 hours.
Mixture is cooled, filtered, acidified with HCl and evaporated, which takes another entire day.
Day 3: It is noteworthy that at this point, I took a small sample of the crusty dried salt mixture and extracted it with acetone, resulting in nearly
white crystals of mixed salts and a dark acetone solution, which upon evaporation yielded a black goo that somewhat solidified to a deep brown paste.
The noteworthy thing here is that no noxious fumes were generated at this point.
A repeated process took place, as I have no soxhlet, of placing the dried reaction mixture into a 500mL boiling flask and refluxing it with
approximately 200ml dichloromethane for around 20 minutes. This was then allowed to cool, poured off, filtered, and distilled, resulting in really
nice looking light-tan plates of 5-hydroxyvanillin which likes to start turning brown when it gets a chance. The hydroxyvanillin was allowed to
remain in the 1L boiling flask the solvent was being distilled from for the 2 day duration of the extraction effort, which resulted in accumulation of
extracted hydroxyvanillin in the flask along with residual remaining solvent.
Finally, once satisfied that no more hydroxyvanillin would be extracted from the reaction mixture, the solution from the boiling flask containing the
cumulative extract of hydroxyvanillin was poured out onto a plate. At this point an unusual smell (sort-of chlorinated hydrocarbon smell, sort-of
just awful smell) was noticed and an immediate sensation of dopiness and dizziness was noted. Ever dumb and fearless, I pressed on, giving heat and
ventilation to the solution.
After a couple minutes, I noticed that something was clearly wrong. I could smell this awful smell coming from the lab, so I investigated. No
personal protective equipment, no fume hood, just sheer idiocy and willingness. The vapor coming from the plate was incredibly irritating to the
eyes, nose and throat. So I took it outside and dumped it, cleaned everything with water.
Beginning to feel generally quite ill, I decided to do a little experiment with the remaining salt mixture which contained a small amount of DCM. I
poured acetone through it over a cotton filter plug into a glass flask which had just been washed and contained a little water. Intensely irritating
fumes, feeling peppery to the eyes and throat, rose up from the funnel. Underneath, where the acetone hit the water, it separated into two layers,
with the bottom layer looking distinctly like DCM containing bromine.
Of course all of this was washed up as soon as possible and the area was decontaminated to the best of my ability, but in so doing, again stupidly
without any personal protective gear, I became sufficiently exposed to produce what seemed to be symptoms of bromine toxicity. (to be continued)
[Edited on 28-9-2017 by wakatutu]
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wakatutu
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(continuing from above)
Here are the exact notes describing the problems at the time, when I seriously feared for my life.
"I think bromine was present in good amounts because I tried to extract the remaining salt mixture with acetone, and when this contacted water, a deep
bromine-colored DCM solution separated. Fumes were peppery to the eyes, there was a bad-smelling and highly irritating vapor with or without acetone
present. This caused some distress - tight throat, a little lung pain, painful eyes, weird feeling on the tongue, dryness of throat, coughing. After
a few minutes this goes away, but feeling unwell afterward. Feeling a bit hot, a bit shaky. Drinking water helps to normalize a little. "
Then about an hour later I wrote
"Apparently it just gets worse as time goes by, as far as noxious shit goes. Yeah, I feel a bit weak. Hopefully it's all good. I've had some CNS
effects (dopiness), my chest feels varyingly painful (at first, this has subsided), tight, dry. This stuff comes and goes. My throat feels dry and a
bit sore. Drinking lots of water, peeing very frequently (about every 7-10 minutes). My arms and legs were a bit tense at first, now they are
tingly. My heart beat was heavy and fast for a bit there, correlating with both peak symptoms and panicking. It does seem like symptoms are
subsiding. Still feel a bit woozy."
These are the symptoms I experienced at the time of the exposure. It seemed to be similar to a previous bromine exposure which I documented on this
site. Reading the stuff I wrote at the time, I was trying to keep myself calm by underreporting the severity of the CNS effects. I felt absolutely
drunk and spaced out. I was concerned that I might have exposed myself to phosgene or some other horrible chlorinated/brominated organic compound.
For two days I just felt pain in my chest and throat and weakness in my limbs, with dizziness and malaise. However, on day 3 I had a very strong
onset of severe neurological symptoms. It felt like I might have been having a heart attack. The symptoms were:
Serious pain in the right side of my chest
tightness and pain in my right armpit and right groin area
intense numbness and tingling in my right arm and right leg
severe dizziness
tenderness and ache in right calf muscle and right lower back
loss of coordination and balance (varying)
uneven walk, unable to walk quickly
bleeding profusely from gums
mild visual changes
tinnitus
This delayed onset of effects caused me to have a delayed onset of going to the hospital. There they tested for heart problems and found none. No
blood clots, and my blood tests also appeared normal. This was quite the concern itself, because I was sure that there would be something weird about
my blood.
The symptoms only occurred for the most part during 3 hour long attacks, and would subside back to not-quite-normal (a little dizziness upon rapid
motion, and severe fatigue).
A week later, with each progressive daily attack intensifying, it reached a climax of horribleness when the numbness spread to my entire face and I
had a sensation of pressure behind the eyes, accompanied by convulsions. On the ER visit which this lovely set of symptoms inspired, there was
imaging of the lungs, heart, brain, more blood tests. They indicated nothing wrong with any of these organs, but I was surprised to see that my
chloride levels were much higher than they had been a week before, which indicates bromine as the offending agent.
Subsequent blood tests aimed at identifying thyroid issues and b12 deficiency came back normal. Gradually the symptoms have been lessening. My lungs
feel almost back to normal, the neurological symptoms are much less intense, and I don't have daily episodes, just occasional ones. It's been a
month, and now I'm going to be seeing a neurologist.
Anyway, none of this stuff in the second post really is aimed at this particular crowd, I guess I'm just complaining.
The lesson I've learned from all this is to stop fucking around with things I think I understand, because I don't understand this stuff. Obviously.
I'm still interested in organic chemistry but I'm feeling a lot more cautious about my approach to the field. In fact I've abandoned my whole line of
research into organohalides and have visited the local waste disposal plant with clearly labelled containers of everything hazardous I had in my lab.
I might be selling my glassware soon. I'm just very put off by this whole mess.
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CRUSTY
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Well, if this were a little more concise, I'd suggest that maybe it would make a lovely sticky as a cautionary tale. I can't help but say you
should've gotten out of there the instant you had a high concentration of an unknown gas, but I'm glad you're okay though. I can see why you're
discouraged to continue, but think of it this way: you're never going to screw up like that again (or at least I hope that was the moral of this to
you). Of course I would never want to see someone get scared away from chemistry, but given the circumstances, I don't think it's unreasonable to feel
that way.
Microwave fans make excellent modular fume extractors, if you're into that (they're usually all plastic and any wire is coated in an enamel). Also,
get a respirator and some multi-gas filters, they are unbelievably useful for their price. My respirator put me down around 100 USD (3M Full-Face 6000
series respirator, I had it before I got into chem), $10 for the filters, but it not only makes safe chemistry easier, it makes it SO much safer. I
was screwing around with adding methanol to my lawnmower fuel, filling my deck area with an absolutely intolerable stench of gasoline fumes, put on
the respirator, couldn't smell a thing, even with hard inhalation. It also works just as well for chlorine, ammonia, SO2, etc. I will never
regret that purchase. I'd highly recommend doing the same.
[Edited on 29-9-2017 by CRUSTY]
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Melgar
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Elemental bromine is very easy to see. It's a deep orange as a vapor, and hard to miss. It's also heavier than air and tends to settle near ground
level. I've used it plenty of times without a respirator (though with ventilation) and gotten whiffs of it here and there with no ill effects. What
you're describing sounds like it might have been an alpha-brominated ketone, as they're very easy to accidentally make, and are pretty awful tear
gases. Would you have had any ketone in contact with elemental bromine? Say, acetone or acetophenone?
The first step in the process of learning something is admitting that you don't know it already.
I'm givin' the spam shields max power at full warp, but they just dinna have the power! We're gonna have to evacuate to new forum software!
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wakatutu
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Short answer, yes, there was a ketone in contact with bromine, I think.
Long answer: these are hypotheses.
-Bromine, due to the presence of bromide salts and CuSO4/Cu++, because of possible oxidation of halide salts to halogens by copper sulfate.
-Bromine Chloride, as there was HCl and NaCl also present.
-Phosgene, as there was Cu++ and Dichloromethane, which has been demonstrated to produce phosgene in reaction with oxidizers or high temperatures.
-Bromoacetone, as a secondary product, as I was using acetone to clean up the mess. This is, however, after I had already noticed highly irritating
vapor coming from the reaction.
-Bromodichloromethane, which is hard to find info about, but could possibly be neurotoxic.
-Bromomethanols, or formyl bromide/formyl chloride; that there might have been methanol left over in the DCM, which was derived from paint stripper.
This could have reacted with bromine to produce formaldehyde and formyl bromide. I can't find any info on formyl bromide, but it sounds like a nasty
piece of work.
Does bromoacetone cause severe neurological disturbances? It's also proving difficult to find information about.
[Edited on 29-9-2017 by wakatutu]
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CRUSTY
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Whelp, this seems like some shit-show of a mystery at the moment.
Two things:
First, and I'm no doctor, but severe stress can cause most of the symptoms you listed. I once had an issue with an experimental apparatus that
unexpectedly heated a copper part up to the point where it began to catalyze the pyrolysis of acetone to ketene, among other things. I had never had
an issue with ketene before, but at that point I got a nasty whiff of the gas, and panicked thinking it was ketene. I immediately shut down the
reaction, but started to feel an extreme tingling in my hands and fingertips, along with shortness of breath and dizziness. Of course, I didn't know
that these are not symptoms of immediate ketene exposure (I no longer believe it was ketene that was generated anyways, it smelled vaguely of
acetaldehyde), but the fear of such was enough to make me feel very ill. I would have gone to the ER had the symptoms not gone away once I calmed
down. Long story short, it was some sort of a panic attack caused by the magnitude of the scare which the potential ketene release gave me. I've got
various anxiety disorders, it's in my nature.
Anyways, my point with that is that, although I have no medical experience or certification and you should not take any medical hypotheses from the
internet as fact, maybe it was stress (?), or at least part of it was, since these effects were very long-term for a stress response, and the
hyperchloremia isn't explained by this hypothesis.
Second, I don't mean to assume anything about you or what you intend to do with the products of this reaction, but given the nature of the compounds
you can produce through the exact route you are using, could it be possible that the offending compound was a derivative of
5-hydroxyvanillin? Compounds of such structure are pretty frequently neurologically active, regardless of whether they possess the phenethylamine
moiety not. Maybe there were side reactions as a result of the larger reaction scale. Just something to consider, it's too early in the morning for me
to produce anything coherent.
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wakatutu
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I've certainly considered that stress was a factor but there was absolutely an underlying toxicity involved in the symptoms.
Moreover, the reason I posted the lab notes was in hopes of someone better informed about chemistry being able to indicate what possible toxic gases
might be produced, particularly ones which are slow to develop in this system. Previous experiments with this reaction went from start to finish in
48 hours, but this one took 4 entire days, and was the only instance where a toxic volatile compound/element was generated.
The symptoms I posted both as a warning to others, and as a means of identifying the compound responsible. As stated, I am involved with medical
people and getting the care I need.
Sorry to hear about your chem-related health problem. Thanks for your responses CRUSTY and Melgar.
If anyone can find case reports of exposure to any of the above listed compounds I would appreciate a link. I can't find it myself, and I have
scoured the net.
Also...I've heard reports on this site of people trying to cleave aryl-methyl ethers with HBr and meeting varying levels of success. Obviously MeBr
would be a result of this cleavage, and I was incubating under DCM (a solvent which could potentially hold on to the volatile MeBr) a mixture of NaBr,
HCl, hydroxyvanillin, and leftover Cu++ salt. MeBr has a pretty nasty set of effects on the CNS.
MeBr isn't a strong irritant but if it was a mixture of Br2, MeBr, and bromoacetone off-gassing then I could have experienced a mixture of effects
from different poisons. I don't know.
EDIT: also just to point out, I exist in the Chemplayer school of being fascinated by all the nifty reactions the "cookery" types like to do, and
enjoy the accessibility of the literature they produce and the accessibility of the materials they rely on, but do not relish the idea of producing
harmful or illegal substances. I particularly like the personality presences in the "cook" literature. While a referenced publication might say, "we
experienced little success with this route" a clandestine source would say, "this reaction is a bitch to get to work right and it only ever gives
shitty yields." And really that's a lot more relatable. I like that about this site too.
[Edited on 29-9-2017 by wakatutu]
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clearly_not_atara
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That sounds very unfortunate. I hope you feel better soon. Don't start doing chemistry again until you do feel better.
I think the best guess is bromine, with a weak maybe on MeBr. But MeBr should require pretty strong acid to form, and it should have evaporated when
you first evaporated the rxn mixture. On the other hand, bromine oxidation by cupric ions is not too surprising, and considering it made
bromoacetone (apparently) there's not much else that could have been there. I would bet that a lot of the ill effects you experienced were due to the
bromoacetone exposure which should have been completely avoidable. Bromoacetone and related haloacetones are extremely toxic. If you suspect a halogen
has gotten into your product in the future, you can try to detoxify with ascorbic acid (vitamin C) or a polyunsaturated fat such as peanut oil or
canola oil. These produce no volatile byproducts.
Also, Br2 could remain in the solid by formation of one of the trihalide ions Br3-, Br2Cl-, or BrCl2-, the first and last are known and the middle one
seems reasonable unless it diproportionates into the other two. These trihalides wouldn't dissolve in acetone but they would probably decompose with
heating and the halogen result will certainly dissolve in DCM. This, you would have smelled, upon opening the flask, but not in the first "test"
extraction (because it was locked up as tribromide).
Never sniff. Waft. If you must. Using your hand to direct a smell towards your face prevents the concentration of the chemical from increasing too
fast.
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Crowfjord
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Can Cu2+ oxidize bromide to bromine? That's an interesting thought. Bromo or chloroacetone could be a possibility - I accidentally made a
tiny amount of chloroacetone once by boiling some anhudrous copper (II) chloride in acetone. Despite being in a fume hood my eyes still felt like I
had been chopping onions in an unventilated kitchen. DCM on its own can be quite irritating as well.
I think hydroxyvanillin might also oxidize from air under basic conditions to form the corresponding ortho-quinone. I doubt that it's very volatile
(melting point is 115 C) but maybe could contribute to formation of other nasties.
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Melgar
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It makes more sense to me now. Bromine exposure (of the type you described) is very irritating to your eyes and throat, but it's like getting smacked
in the face: you feel it most strongly immediately, and it stings for a while afterwards, but it doesn't last very long. Bromoacetone, on the other
hand, is a regular tear gas, and it's not something that you feel instantly. The time I accidentally made it, it was hell for a few hours, and
because I had the stuff on my hands without realizing it, whether through my gloves or I got it on my hands while taking my gloves off, I'd rub my
eyes, and because of the delayed onset, I wouldn't realize I'd just made it worse until about a minute later. I didn't want to spread the stuff
outside of my lab area, so I remember just laying there in agony with my eyes running into a towel I put over my face. No long-term effects, but I
sure learned a lesson that day.
Note that I may be describing bromoacetophenone, I can't remember which one it was now.
edit: To be clear, I think that you were exposed to both bromine and bromoacetone, and assumed that it was the same chemical that was causing all of
your symptoms.
[Edited on 10/1/17 by Melgar]
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woelen
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Copper(II) does not oxidize bromide to bromine under normal conditions. I have a sample of anhydrous CuBr2 (a black solid, looking somewhat like
iodine) and when this is dissolved in water you get a purple solution if the concentration is very high and a blue solution at low concentration. No
bromine is formed. Only when the solid is heated to a few hundred degrees centigrade, you get red/orange vapors of bromine.
I once had quite some exposure to elemental bromine. It does not produce symptoms like you describe. It becomes very irritating in the nose and upper
respiratory tract, but I never had an experience like you describe with severe neurological symptoms. These symptoms almost certainly must have been
the result of exposure to some organic compound. Which compound, however, I cannot tell.
The lesson learned from this is that you should not mess around with things you don't know well in large quantities. I also think that experiments
with complicated organics are more risky than experiments with simple inorganic compounds. Such complex molecules can have weird effects on the human
body. Not the direct "honest" attack which some inorganic compounds can give, such as Cl2, Br2, HCl, SO2, but more subtle symptoms, which become
moticeable after a somewhat longer time.
The closest experience I had in this direction was when I mixed acetone, chloroform and NaOH in a solution of ethanol in fairly large quentities. The
acetone and chloroform react in this situation to form chlorbutol (which has structure CH3C(OH)(CCl3)CH3). This stuff has an amazing fresh/cooling
smell, but after a while I became very drowsy. It was as if my sense of consciousness was detached from my body. All my movements felt like being
indirect, like being controlled by my thoughts but being executed by some remote entity. Since that experience I decided not to do that kind of
experiments anymore.
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chemplayer...
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Very likely to be a combination of an acute reaction to bromoacetone, a shock-type reaction in response to the unexpected happening (blood pressure
drop, dizziness etc.), and then potentially an unlucky sensitisation and immune response to that which resulted in the reoccurring symptoms. How are
you now?
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wakatutu
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Thanks for your responses. All of you have shared valuable knowledge, mostly in the form of forum posts, but also in the form of everyone's favorite
youtube chemistry videos.
Things have gotten better. After experiencing a distinct 2 week-long decline in my health, the symptoms stopped happening as abruptly and after about
5 weeks I had only slight numbness in the face and toes during episodes that lasted less than 2 hours. Now it's starting to not happen every single
day. I am back to work and there are no functionally impairing continuing neurological problems, but there is still a mark on me. I still have
symptoms which recur almost daily. There has been a significant delay in getting an appointment with a neurologist but I will post here when more
information is available.
Also, by some coincidence I found myself reading about copper II bromide and I think it is a key component of "what went wrong."
CuSO4 + 2NaOH ---> Cu(OH)2 + Na2SO4
Cu(OH)2 (heat)-----> CuO + H2O
CuO + 2HBr ---------> CuBr2 + H2O
According to wikipedia, "Copper (II) bromide in chloroform-ethyl acetate reacts with ketones resulting in the formation of alpha-bromo ketones. " We
all know there is some similarity between Chloroform and DCM. So it seems likely that CuBr2 was the brominating agent, and that bromoacetone exposure
is likely the source of my neurological injury.
I did notice dizziness and clumsiness prior to addition of acetone to the scenario, so I am still thinking it is something else which, in combination,
caused the wide array of ugly effects I experienced.
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Sidmadra
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I was almost going to say that your effects could be resulting from some form of psychological PTSD from traumatic chemical exposure, but then I saw
you said your gums were bleeding? That's harsh man :/. I give you my best wishes for quick recovery.
What I was going to say before I saw the bleeding part, was that I have had my lab accidentally filled with very unpleasant halogens and related
compounds on more than 1 occasion, and despite doctors finding nothing wrong with me, the encounters left me with some form of PTSD. I could be
sitting here on my couch, months after an exposure, and start thinking about the exposure, and start experiencing many the symptoms of the instance
all over again. The worst was with formaldehyde gas. If I even start thinking about the time I over boiled some formaldehyde solution, my chest starts
to get tight, my eyes start watering, throat clenches, difficulty breathing, along with many other symptoms. Purely psychological at this point.
Now, I doubt that is the case with you since you said your gums were bleeding.... but I still wanted to post this to suggest that, later on, even if
all your physical symptoms are gone, and yet you still feel like you are experiencing unpleasant symptoms, it could in fact be some sort of
psychological trauma - it doesn't mean you've experienced some form of permanent physical damage.
Regardless of the cause, I hope you get better, and please remember to always be as safe as you can in the lab... Sometimes crap just goes side ways,
no matter how safe we are trying to be. Danger is unavoidable sometimes with amateur chemistry. Being able to be truly safe only comes with
experience. I'm sure there's not a chemist out there who hasn't choked as the result of something they were working on.
[Edited on 18-10-2017 by Sidmadra]
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Mothman
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Wikipedia has a nice page on potassium bromide, the reason I post this here is because the symptoms of overdose are very similar to what you
experienced. It is used as an anti-convulsant, and the activity of it is primarily on the CNS. It isn't the potassium part of the compound that has
these effects, its the bromide ion, as potassium chloride has no similar effects, leading me to believe it to be the bromide ion. I have no clue what
your body would've metabolized Bromoacetone into but the bromine in your body appears to be the main cause of your issues. You mentioned that after
about two weeks the symptom frequency decreased, which further supports my bromine poisoning theory as the half life of bromine in the body is two
weeks according to Wikipedia's page on sodium bromide (the most trustworthy of sources, take everything I say with a grain of salt...pun not
intended). I hope that you make a full recovery, it really sucks that this happened, and I really hope you don't let it scare you away from chemistry,
but it is entirely up to you, good luck man!
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wakatutu
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Well, the world keeps turning and I keep mostly improving, as I hope all of you are as well!
I keep returning from other matters to question, just exactly wtf did I poison myself with? It's a mystery I still can't say I've all the way solved
at all.
The neurologist believes that I am suffering from a congestive type of migraine, which I can't remember the name of but it manifests experientially as
hemiplegic migraine.
I think it's most likely that multiple toxicological agents were at work in this scenario. I spent some time reading about methyl halides, and this
fuelled either more rabbit-hole type intellectual shenanigans OR progress toward identification of the material(s) which induced my still-lingering
neurological problems.
The clinical presentation for exposure to methyl chloride, as presented in a paper I found from 1947, nearly identically resembles the symptoms I
experienced, including the delay in the onset of neurological symptoms. Exposure to all methyl halides seems to present clinically with the same
symptoms but small variations. Previously I had wondered if methyl bromide was generated by interaction of HBr and 5-hydroxyvanillin, but it then
occurred to me that the quantity of MeBr that would be generated from that would be lower than an amount needed to generate toxicity.
So now I have more ideas about what might have happened. One involves reduction of dichloromethane to monochloromethane. Another involves
Finkelstein-type halogen swap, producing bromochloromethane. This would also potentially be more amenable to reduction, this time to a mixture of
methyl bromide and methyl chloride, but mostly methyl chloride. I don't know what mechanism would induce this reduction, but I am considering that
an organo-copper complex may have formed which would exhibit catalytic activity. Tetrachlorocuprate or tetrabromocuprate may have been formed in this
reaction. Hydroxyvanillin is also possible as a reducing agent, since it is apparently susceptible to oxidation in air.
I have tried reading about the reaction of HBr and DCM or HCl and DCM and haven't found anything significant. Perhaps in all those trihalide ions
that were pointed out earlier in the thread, there exists a mechanism for abstracting chloride ions from an organochlorine compound?
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Loptr
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Quote: Originally posted by wakatutu  | Previously I had wondered if methyl bromide was generated by interaction of HBr and 5-hydroxyvanillin, but it then occurred to me that the quantity of
MeBr that would be generated from that would be lower than an amount needed to generate toxicity.
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How would HBr and 5-hydroxyvanillin produce methyl bromide? I think you mean 5-methoxyvanillin. Where else would that carbon come from?
"Question everything generally thought to be obvious." - Dieter Rams
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wakatutu
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There is a single aryl-methyl ether (aka a methoxy group on the benzene ring), at the 3 position of 5-hydroxyvanillin.
However it doesn't seem likely to me that demethylation via HBr was a significant source of toxicant.
I really am looking at dichloromethane as participating in a chemical reaction when I had been employing it as an extraction solvent, since I was
heating it for what amounted to hours in the presence of:
-NaBr
-NaCl
-Residual HBr and HCl
-5-hydroxyvanillin
-Copper which at the time had been converted to CuO, Cu2O, CuBr and maybe HCuCl4, HCuBr4, etc.
-residual water
And it was surmised during the hasty cleanup/max concentration exposure, that bromine was present in a good amount, as was made apparent by adding
acetone and it pouring into water.
I'm mostly leaning toward the reduction of DCM to MCM, as DCM was present in sufficient quantities to generate a toxic level of MCM, whereas the
methyl ether group from the extraction substrate didnt have enough to form such a high level of methyl bromide. There could be a complex set of steps
that leads from DCM to formyl chloride via oxidation with bromine, then reduction via hydroxyvanillin to chloromethane, leaving oxovanillin or
hydroxyvanillic acid or something.
It's very important to me that this mystery is solved. Mostly I wanted to post this post as a warning to others attempting the same reaction, but it
also would be very helpful to me if I knew what chemical caused this health problem I have (but am mostly recovered from....but definitely not fully
recovered).
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Loptr
International Hazard
Posts: 1348
Registered: 20-5-2014
Location: USA
Member Is Offline
Mood: Grateful
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You are right about the vanillin having a methoxy function. I don't know what I was thinking, actually I was thinking protocatechualdehyde for some
reason. Thanks for the correction.
"Question everything generally thought to be obvious." - Dieter Rams
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