Sciencemadness Discussion Board

Benzoquinone situation

Blankeyblank - 6-5-2015 at 17:26

When I first tried this I bought a 30 % H2O2 under the name Baquacil and I tried the Erowid version of the synthesis and dripping the H2O2 with almost no fizzing in a two necked 500 ml rbf which only resulted in quinhydrone. Only until I boiled the reaction contents for a minute to a minute and a half while refluxing after I added the H2O2 wholesale did the hydroquinone go all the way to Benzoquinone after the boiling I would chill the rbf immediately in an icebath and then it would promptly go into the freezer for crystalization. Now I have returned to make more with the same gallon of H2O2 which I put in a refridgerator and I painted the walls when I added the H2O2 wholesale and tried to boil it the first time which prompted me to make a blast hood out of 2x4's and clear plastic. I took the Baquacil out of the fridge and let it sit for a day or two hoping the temp would raise and it would react like it did in the past and it seemed even more exothermic when I tried to add it wholesale somehow because as soon as I added it it geysered right away. So on a third attempt I refluxed and dripped the H2O2 very slowly otherwise it would start to bubble and the flask would heat up quite a bit. I am thinking about just buying another gallon of Baquacil because I keep thinking that I strengthened it greatly with the fridge and all that has resulted is no Benzoquinone and not even any Quinhydrone just a purply liquid that seems almost scorched. Should I be using an ice bath the entire time on the rbf with what seems like a much more powerful H2O2? Could it be that at the beginning what I poured off was a weaker concentration out the top of the gallon and now I am getting down to the greater concentration? Really at a loss here because this DID work before!

byko3y - 6-5-2015 at 18:07

Did you use 0.5-1.0% of iodine as a catalyst?
Did you check your H2O2 concentration? You can use either permanganate or iodide salt for that.

Blankeyblank - 7-5-2015 at 14:24

I can't remember off the top of my head but would too much catalyst result in a much more violent reaction? I may have used half a gram more like 1.5 grams for every 55 grams of hydroquinone. No I did not check the concentration is there a cheap way to get iodide salt or permanganate or anything else to test it OTC?

Hawkguy - 7-5-2015 at 15:07

What are you using the Benzoquinone for? It's an MDMA precurser, but I guess you knew that. If you're interested in the science, you can make it from Aniline, using Potassium Dichromate. That process is better, but more expensive if you have to go all the way from Toluene -> Benzoic Acid -> Benzene -> Nitrobenzene -> Aniline -> Benzoquinone...

Blankeyblank - 9-5-2015 at 19:27

Yes I am cooking mdma, meth, heroin, snorting coke, and eating a live baby as I write this. Oh and I have come for you soul!!! Mu-hahahahaha!!!!!

turd - 14-5-2015 at 12:37

In case you have missed it, there is already a thread on this topic:
https://www.sciencemadness.org/whisper/viewthread.php?tid=14...

Ignore my post in that thread: no acid needed.

IMHO you use too much I2. I use a bit less than 1g / 110g HQ and never had this reaction fail. Consistently 80-90% after drying in vacuum. The less I2, the less IPA washes, the less losses. Refluxing seems like a bad idea. Heat gently, once the reaction becomes significantly exothermic stop external heating. No need to cool in an ice bath as well. Just stir until it has cooled down enough. If for some reason reaction is not complete (black quinhydrone present) gently heat and add some more oxidant.

I doubt that you have concentrated up you H2O2. You can check with titration, the topic has come up before.

PS: Good call to react lightly to these idiotic allegations.
Quote:
If you're interested in the science, you can make it from Aniline, using Potassium Dichromate. That process is better, but more expensive if you have to go all the way from Toluene -> Benzoic Acid -> Benzene -> Nitrobenzene -> Aniline -> Benzoquinone...

This is one of the most absurd things I have read these parts.

Chemosynthesis - 14-5-2015 at 14:22

Quote: Originally posted by turd  
In case you have missed it, there is already a thread on this topic:
https://www.sciencemadness.org/whisper/viewthread.php?tid=14...

Ignore my post in that thread: no acid needed.

IMHO you use too much I2. I use a bit less than 1g / 110g HQ and never had this reaction fail. Consistently 80-90% after drying in vacuum. The less I2, the less IPA washes, the less losses. Refluxing seems like a bad idea. Heat gently, once the reaction becomes significantly exothermic stop external heating. No need to cool in an ice bath as well. Just stir until it has cooled down enough. If for some reason reaction is not complete (black quinhydrone present) gently heat and add some more oxidant.

I doubt that you have concentrated up you H2O2. You can check with titration, the topic has come up before.

PS: Good call to react lightly to these idiotic allegations.

Quote:
If you're interested in the science, you can make it from Aniline, using Potassium Dichromate. That process is better, but more expensive if you have to go all the way from Toluene -> Benzoic Acid -> Benzene -> Nitrobenzene -> Aniline -> Benzoquinone...

This is one of the most absurd things I have read these parts.


No one in this thread alleged; someone asked, which can be important in determining how pure a reagent must be. It's a perfectly valid assumption, though given that the only other post made by the thread starter acknowledges making MDP2P. Stop being so sensitive.

As for recommending isopropanol washes, that is a poor choice in solvents for the purpose of residual iodine removal, assuming you have removed what is likely hydroquinone starting material, and is likely only suggested as it's originally derived from an industrial procedure. Fewer washes and/or reduced losses could be utilized by using a different solvent system, or even purification approach.

OP, you should preferably link to the synthesis you used and always note any discrepancies from source material. There is more than one "Erowid version" for benzoquinone synthesis. Are we to assume you used [4] from here: https://www.erowid.org/archive/rhodium/chemistry/benzoquinon... derived from US Pat 4,973,720? That you can't state quantities used makes it very difficult for anyone to truly know what occurred; if you don't know what you did, how do you expect us to? This includes testing reagent purity, as there are shelf lives and expiration dates.

aga - 14-5-2015 at 15:04

Quote: Originally posted by Blankeyblank  
Yes I am cooking mdma, meth, heroin, snorting coke, and eating a live baby as I write this. Oh and I have come for you soul!!! Mu-hahahahaha!!!!!

Sigh.

You came for his soul right ?

That should read 'i have come for your soul'

Do deamons not learn anything in daemon school anymore ?

turd - 14-5-2015 at 23:14

Quote: Originally posted by Chemosynthesis  
Stop being so sensitive.

I'm not sensitive - you're naive. Hawkguy was not trying to be helpful, on the contrary. And I thought OP's reaction was better than the usual whiny/defensive one. So props.

Ad washing with small amounts of cold (~0°C) IPA: There is always better solvents, but as someone who actually does amateur chemistry and successfully ran this reaction numerous times, my opinion is that a protocol that consistently gives 80-90% does not need optimization. IPA is obviously at hand since it is the reaction medium. At first I used to cool the combined filtrates to -20°C for a few days to obtain more product (giving >90% yields) but later decided that it's simply not worth it, given the price of hydroquinone.

Two more points:
- I use less IPA than peach and apply gentle heat to dissolve the HQ.
- I cool at 0°C overnight before filtration.

Chemosynthesis - 15-5-2015 at 01:25

Quote: Originally posted by turd  
Quote: Originally posted by Chemosynthesis  
Stop being so sensitive.
I'm not sensitive - you're naive. Hawkguy was not trying to be helpful, on the contrary. And I thought OP's reaction was better than the usual whiny/defensive one. So props. Ad washing with small amounts of cold (~0°C) IPA: There is always better solvents, but as someone who actually does amateur chemistry and successfully ran this reaction numerous times, my opinion is that a protocol that consistently gives 80-90% does not need optimization. IPA is obviously at hand since it is the reaction medium. At first I used to cool the combined filtrates to -20°C for a few days to obtain more product (giving >90% yields) but later decided that it's simply not worth it, given the price of hydroquinone. Two more points: - I use less IPA than peach and apply gentle heat to dissolve the HQ. - I cool at 0°C overnight before filtration.
We don't know what Hawk had in mind. Maybe he wanted to offer some alternative preparation to avoid iodine removal or maybe he saw no desire to help the OP, which is perfectly acceptable. From my perspective, clearly you are sensitive as you frequently insult people directly whom you seem to either take drug offense from or don't believe are as helpful as you would prefer for some reason, and are quick to mischaracterize posts (I.e. accusation or naivete here in this thread.) You thought the reaction scheme to get hydroquinone was idiotic, but didn't mention why. My interpretation was that an arduous route, while synthetically inefficient, teaches a great deal of practical chemistry. Clearly this has both pros and coins and may not be applicable or desirable for the OP. I am sure you have noticed members here claim to be making a certain chemical or performing a reaction for curiosity's sake, much like some of the basic chemistry research labs in academia, devoid of a preordained practical application. To claim someone is trying to be unhelpful as though you have psychic gnosis divined in some manner, yet calling another naive is pretty ironic.

As for actual chemistry (as though you are the only one who enjoys it in a nonprofessional setting... which is incorrect given common sense and the very forun's existence), not only does my professional experience point towards pet. ether or hexane trituration, possibly with the addition of a small amount activated carbon until the solution clears considerably, being superior for I2 removal, but similar have been suggested in the thread you linked. Also see J. Org. Chem. 1989, 54, 731-2 (pentane being largely fungible), Amarego and Chai, etc.

This won't remove quinhydrone intermediates or the like, but would likely serve a great improvement over the linked threads repeated statements of poor iodine removal. You claimed that XS I2 necessitated more IPA washes. You either mistyped or were mistaken. The mature thing to do is admit this, rather than insinuate appeal to hobby chemistry in some bizarre manner on a forum dedicated to the topic as though someone will offer you a medal.

The added expense of an additional solvent that is readily available most places I am familiar with, and can be recycled, is minimal and must be compared with affects on yield and purity. This can include cooling. If you don't find this useful, perhaps others such as those who expressed difficulty in purification in the thread you linked will. It isn't as though the OP is forced to use amberlyte or DC18C6 crown ether, nor is even chromatography out of reach to a hobbyist, as seen in the recent TEMPO workup thread in prepublication. Simplifying process streams, logistics, optimizing flashpoint/autoignition temp safety hazards, and even some waste protocols are typically more of concern in industrial or process chemistry scale up.

turd - 15-5-2015 at 03:25

If you want to contribute something of use, go ahead and optimize this procedure. At first quantify how much is lost in each step. There is no point in optimizing away 10% of the losses if the remaining 90% come from somewhere else. As opposed to you I know from experiment that you can use much less I2.

At the moment you're just producing walls of useless text on procedures you didn't perform. Hot air as usual.

Chemosynthesis - 15-5-2015 at 08:00

I think anyone who looks through our posts can tell I contribute more than you, particularly since I post new information vs. your repeating of old information, some of which isn't even accurate. You also make tons of assumptions about reactions I have and haven't performed with no basis for said assumptions, or that an individual has leftover isopropanol but can't be bothered to get a straight chain alkane for some reason. Again with the psychic routine. You're not entitled to my doing all your work for you, though I can see you are used to others coming up with procedures for you to copy. You could always post your reaction monitoring data for a reaction kinetics determination vs. temperature and catalyst rather than just throw vague references to experimentation and your "opinion" sans data around too, but you don't.

I never said you can't use less catalyst, which should be common sense given the remaining iodine upon completion, which doesn't appear sequestered or otherwise poisoned, though this may impact your rate... I said that if too much is used (or cooling is applied and iodine is trapped in the product lattice, for example), there are alternative ways of removing it. You very incorrectly said otherwise. What a contribution to the forum. If washing in some form or fashion (which I added to in lieu of using activated carbon as a stationary phase in a crude column) isn't your preference, perhaps a recrystalization from an appropriate solvent and alkane is warranted. Speaking of contribution, it appears others were the ones to confirm the use of less catalyst without significant yield or rate impact. While you're telling people what to do, feel free to actually read and learn a little. If in your own words you express that you don't want to optimize a particular reaction (no surprise there on your part) then don't. No one is forcing you to. Not only are we discussing yield but purity, given other posts. Both can be important, depending on intended use. Ignoring the latter is ignorant on your part. Revel in it for all I care. Others capable of integrating new information can utilize this.

[Edited on 15-5-2015 by Chemosynthesis]

turd - 15-5-2015 at 15:51

You still didn't understand the crucial point: I know this reaction - you don't.

Therefore I know that using my parameters, there is virtually no I2 left in the filter cake (due to large crystals and the low I2 concentration) and therefore the whole idea of using a different solvent is irrelevant yield- as well as purity-wise.

As opposed to you I know that there is no hydroquinone left - discussing this is pointless.

As opposed to you I know where the yield goes if you don't use too much I2 - hint: it's not in the rinsing of the filter cake. Discussing yield optimization without understanding where the losses go is a typical beginner mistake.

In summary: I can give advice on this particular reaction; you can't, because you don't know what you're talking about. You could change that by actually performing this reaction, all reagents are dirt cheap. Then you could contribute something of interest to this thread. But apparently you try sneak out of it.
Quote:
I never said you can't use less catalyst, which should be common sense given the remaining iodine upon completion

Silly. Of course the amount of catalyst is a parameter to be optimized and it can be both, too small and too large. In the case of the OP it was the latter.

Chemosynthesis - 15-5-2015 at 16:26

Quote: Originally posted by turd  
You still didn't understand the crucial point: I know this reaction - you don't.

You have no idea if I have performed or otherwise "know" this reaction. You don't know if I also have performed additional analogous reactions on isosteres or analogs. You are making an assumption. I recognize that providing peer-reviewed reference for support as I did is of a far greater academic caliber than just pseudonymously claiming to have performed a reaction.
Now you are discussing your conditions and reagents, which I did not discuss nor are they necessarily relevant to the OP. I wasn't telling you to change anything. I was correcting a factual misstatement you made about required IPA washes. Unless everyone performing the same experiment follows your exact motions identically with 100% identical reagents and conditions inside the flask, your experience isn't necessarily any more applicable than anyone else's.

Not every chemical reaction proceeds the exact same way every time, in practical terms, in contrast to what you seem to imply, nor are all reagents identical in terms of purity. With enough experience, you will see this. I have seen academic course labs run twenty reactions or so in fume hoods per student. Some look different than others (more colloidal, variations in color, etc.) I didn't watch each procedure individually, but see a difference in appearance. Sometimes it all ends up the same as far as yield range and purity. Sometimes not. Sometimes external conditions or inexplicable/unmeasured qualities lead to variations in color, slight adjustments in reaction time, etc. without affecting yields. Inter-chemist technique can also impact final results. In these instances (mistakenly or accidentally using 'too much' iodine, cooling as one member did in the other thread, etc.) my information may be considered useful.

Some of these others in the thread you linked had problems purifying their product, as likely would the OP here if he used such a gross excess of catalyst and the reaction proceeded to completion. The only relevance you have regarding my response is in stating one needs to use more IPA washes to remove said iodine. Not necessarily true, hence my correction. As for sneaking something of interest... I shouldn't need to describe each scenario where crystallization with pet. Ether, hexanes, or any other solvents I have experience with can prove superior to temperature control in many practical scenarios due to finer control of crystallization rate and thus greater exclusion of impurities either.

I offered solvent selections and alternative activated charcoal utilizations than had previously been discussed and you implied I had not contributed. My contribution may not be helpful for you, but I was posting it for the intended benefit of everyone here.

[Edited on 16-5-2015 by Chemosynthesis]

turd - 16-5-2015 at 00:24

Quote: Originally posted by Chemosynthesis  
I recognize that providing peer-reviewed reference for support as I did is of a far greater academic caliber than just pseudonymously claiming to have performed a reaction.

Here we'll have to disagree. Experiment and experience always trumps peer reviewed publications. Especially once you realize how much trash gets published in peer reviewed journals, even recognized ones. Reject one paper and have authors submit to a different high impact journal hoping for other referees. That's unfortunately routine in chemistry. Yes, like democracy, it's the best system we have, but the result is often still a joke.
Quote:
Now you are discussing your conditions and reagents, which I did not discuss nor are they necessarily relevant to the OP.

I'm discussing my conditions to OP's reaction. They are relevant to OP, because that's the reaction he's trying to get to work.
Quote:
Unless everyone performing the same experiment follows your exact motions identically with 100% identical reagents and conditions inside the flask, your experience isn't necessarily any more applicable than anyone else's.

Yes it is, because I performed this reaction not once, but many times with different reagents under different conditions and can vouch for it's reproducibility. I've done it from slowly over many hours to "runaway mode" in ~15 min.
Quote:
Some of these others in the thread you linked had problems purifying their product, as likely would the OP here if he used such a gross excess of catalyst and the reaction proceeded to completion. The only relevance you have regarding my response is in stating one needs to use more IPA washes to remove said iodine. Not necessarily true, hence my correction.

The rational thing would be using less catalyst, not bother with washing.
Quote:
I shouldn't need to describe each scenario where crystallization with pet. Ether, hexanes, or any other solvents I have experience with can prove superior to temperature control in many practical scenarios due to finer control of crystallization rate and thus greater exclusion of impurities either.

I offered solvent selections and alternative activated charcoal utilizations than had previously been discussed and you implied I had not contributed. My contribution may not be helpful for you, but I was posting it for the intended benefit of everyone here.

It might be interesting to someone (though isn't this explained in every organic chemistry beginner's manual?), but it is simply not applicable here. Why not post it in its own thread? My problem with your posts is that you hide the valuable information in lots of random rambling. Perhaps it's my non-diagnosed ADHD.

Purification was not OP's problem, but runaway reactions. I guess(!) he's running the reaction too hot with too much catalyst. But the way he describes it, it could also be impurities that catalytically induce decomposition of the peroxide. So my advice still is:
- Use a little bit less IPA than peach
- Assemble apparatus with enough head space and reflux condenser
- Dissolve HQ by gentle heating/stirring (must not be 100% dissolved)
- Add I2
- Slowly drop in H2O2 (should not immediately give foaming/frothing) while continuing gentle heating
- If the reaction becomes noticeably exothermic (reflux), remove heat source
- Continue stirring/dropping in H2O2
- You should get a deeply colored homogenous solution
- Continue stirring until cooled down to ca. 40°
Alternative if you don't get a homogenous solution, but black specks of quinhydrone
- Apply gentle heat and from time to time add more H2O2 until all quinhydrone is converted into golden benzoquinone. It's obvious when this happens.
- Cool overnight at 0°C, workup.

This is one of the reactions that needs a bit of experience, but once you get the hang of it, it is perfectly reproducible. The last three times I performed it, I got the same yield to the gram.

Chemosynthesis - 16-5-2015 at 01:47

Sounds like good advice to the OP. Just to clarify, you are recommending cooling at ambient lab temps prior to refrigeration overnight in contrast with their use of ice bath (my reading and expectation)?

Part of the peer review problem is also false rejection on the part of reviewers due to lack of care in reading, too, such as requesting data that was already provided in a submitted draft. I have called up an editor on a rejection and had them pretty straight up tell me the reviewer who rejected my draft (needed unanimous approval) was clearly too pressed for time to be invited back, based on the poor quality of their comments, but that an appeal would take as long as a resubmission with minor edits. Most of the outright garbage I have seen was out of India and China, and there have been instances where after spamming an editor I finally got a correction to a figure or supplemental entry that ended up making things work.

Other than my suspicion of fudging yields in some papers, I value the data and ease of retraction or comment online that can lead to retraction ala Sezen or Beilawski, though the former is supposedly still publishing. Without a personal repetition of an experiment, or delegating it to someone I trust, I'll still take peer review with known credentials and standard write ups with less salt than an online post, all else being equal.

turd - 16-5-2015 at 09:20

Quote: Originally posted by Chemosynthesis  
Just to clarify, you are recommending cooling at ambient lab temps prior to refrigeration overnight in contrast with their use of ice bath (my reading and expectation)?

That's the way I run it. There seems to be no significant decomposition at IPA reflux temperature, so I don't see the point in quenching with ice. The idea is to grow large crystals. Benzoquinone crystallizes in a platy form without inclusions.

But I don't think it matters too much. These are details that can be optimized once the reaction is working. I really begin to wonder whether OP has for example a iodide in his iodine leading to catalytic decomposition? An experienced chemist would immediately see if the "geysiring" is reflux or formation of O2.
Quote:
Part of the peer review problem is also false rejection on the part of reviewers due to lack of care in reading, too, such as requesting data that was already provided in a submitted draft. I have called up an editor on a rejection and had them pretty straight up tell me the reviewer who rejected my draft (needed unanimous approval) was clearly too pressed for time to be invited back, based on the poor quality of their comments, but that an appeal would take as long as a resubmission with minor edits.

That is certainly unfortunate, but in such a case the author can insist on his rights. The other kind of lazy referee is more problematic: the skim it superficially and accept it with minor revisions kind. After all, a good referee is generally your friend and prevents you from publishing rubbish you will be ashamed of in years to come. That's why authors should always polish their manuscript before submission, you don't want to annoy the referees.

But actually I can understand unwilling referees. It's a lot of work they have to do in principle in their free time. And it's not something that can be turned into credits - i.e. no reviews of reviews. Lately there seems to be an organization that wants to make refereeing creditable, though I'm skeptical. One solution to the problem would be to publish the name of the referees who accepted the paper (see the checkers in OrgSyn). On one hand that would give proof of work, on the other hand, who would want his name to be associated with trash? But that opens another can of worms, so it's a dilemma.

IMHO the problem lies more with the editors not doing their work. Most will only skim over manuscript and referee opinions. If the latter are positive, accept no more questions asked. They do not check whether the referees really covered all the fields central to the paper and did their work. So you'll have papers that are mostly sound but for example the NMR or the theory part is virtually unchecked.

And even the editor cannot take all the blame. When the system insists on ever increasing publication rates and reduced time to publication, then it is rotten. Reviewing needs time. Forcefully reducing time to publication inherently reduces quality.
Quote:
Most of the outright garbage I have seen was out of India and China

I really wouldn't single out those countries. I can give you lots of other examples. Force people to publish a lot and they will publish superficial trash, independent of country.