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Author: Subject: The short questions thread (2)
Sedit
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I thought about that myself John and all I could come up with is something that exploited the Cl in a way to aid in cracking the chain. Its all in the mental what if stage at the moment but being a plumber that generates a good deal of PVC, CPVC and ABS waste why not attempt to make use of it. My goal is Dichloroethane but it appears from the most recently reviewed text that many can be depolyermized to various simple organic acids and such. This even though its not what I was looking for is great news. Oxalic acid from PVC and Acetic acid from PP are just to name a few.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
entropy51
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Sedit, you should be able to buy oxalic at the hardware store as "wood bleach" cheaper than you can make it. Considering that you plumbers charge $89 per hour. Better to remain silent and appear a fool than to open your mouth and remove all doubt. Sedit International Hazard Posts: 1939 Registered: 23-11-2008 Member Is Offline Mood: Manic Expressive 89$ an hour LMAO we got done doing existing jobs along time ago... If you think we only make 89\$ an hour your outcha friggin mind . All new construction baby everything else is a waste of time and people in your way.

Either way yes I have about 500grams of Oxalic acid extracted from Bar cleaner a while back so its of no real concern but its still a great idea to take a look at the reference section and look at the paper that DJF just provided. Im sure you may find something of use in that mess of simple organics one can get from simply heating +catalyst of scrap plastics which are every where on to large a scale as it is. Perhaps if us amatures started recyling we could get a better rep then we have right now.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
not_important
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PVC, PVA, and similar don't neatly depolymerise, on heating PVC and CPVC mostly give HCl and highly unsaturated tars which break down under further heating. Heating with metal oxides usually gives the chlorides or oxychlorides of the metals and organic gorp along with some carbon oxides.

As already said polystyrene and the polyacrylic esters do depolymerise well. ABS does give its monomers to some degree and a fair amount of gorp and char. Wood gives 3 to 5 percent each of acetic and formic acids, depending on the type of wood, and some methanol.

Polyesters such as PET/PETA, and the polyamides such as nylons, undergo alkaline hydrolysis, some nylons hydrolise nicely with strong acids. Polyurethanes can be hydrolyised as well, but many give a complex mixture of their basic components that isn't terribly useful.

Ethylene glycol may be the easiest OTC route to oxalic acid and 1,2-dichloroethane.
Sedit
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Bromination to 1,2-dibromoethane from Ethylene Glycol was the plan to begin with but if I could get 1,2-Dichloroethane with ease on the cheep Im all ears. It don't appear to be the case but I will still keep searching to see what I can dredge up. The last ref was interesting so I kind of want to see what more is instore for these plastics.

[Edited on 12-9-2009 by Sedit]

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
Nicodem
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I suggest you to focus on bromination of ehtylene glycol with HBr or NaBr/H2SO4.
There is no simple way to 1,2-dichloroethane from vinyl chloride (which is a hazardous gas!) and there is even less chance of a feasible depolimerization of PVC. Besides, 1,2-dichloroethane is a very common industrial solvent (for some reason they use it instead dichloromethane where ever possible - maybe it is cheaper on the bulk?). It is a bit less common solvent in the research labs, but still there is no reason why you would not just order it from a chemical supplier. It is not restricted, it is not suspicious in any way, and it is cheap. However, I would still prefer if you would go the amateur route and do your own 1,2-dibromoethane from ethylene glycol, and post the experience.
1281371269
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When distilling out ethanol such that it drips into a beaker, do I risk the majority of it being lost by evaporation? Do I need a closed apparatus, or will sitting the beaker on some ice suffice?
12AX7
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Ethanol doesn't evaporate all that fast. As long as it's cold from the condenser, it'll stay in place. Heck, moonshiners often use a bucket for the reciever.

Tim

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1281371269
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Thanks
Formula409
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I'm after some properties on the following compound (vapour pressure, boiling point, melting point, density): 3-chlorobut-2-en-1-ol

The only information I can find is "predicted information", obviously not suitable if one is using it for school work: http://www.chemspider.com/Chemical-Structure.9979359.html

Formula409.
497
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Why is it that alkylation of tryptamine via routes like these do not alkylate the indole ring nitrogen?

Also would an methylation like this be able to avoid methylating the indole ring nitrogen?
ketel-one
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What is indole? Benzene ring fused to pyrrole ring. Pyrrole is aromatic so doesn't get alkylated obviously.
ammonium isocyanate
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 Quote: Originally posted by ketel-one What is indole? Benzene ring fused to pyrrole ring. Pyrrole is aromatic so doesn't get alkylated obviously.

What are you talking about? Firstly, aromatic compounds, including indole, can be alkylated. Secondly, he's asking about the nitrogens on the compounds being alkylated. The nitrogen on indole has only to N-C bonds and can be alkylated just fine if deprotonated with a strong base.
ketel-one
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Yes, but look closely at the structure. There's an aromatic pyrrole ring hidden in there.
ammonium isocyanate
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Yes, indole is aromatic. This is true. And also completely irrelevent to 497's question. As I said, indole can be alkylates, even though it's aromatic. Including at the N position, because the nitrogen atom has only two N-C bonds for all intents and purposes. Why the special focus on the aromatic pyrrole ring? The benzene ring is aromatic too.

ketel-one
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Ammonium, I love you with all my heart. But I am dumbfounded by your responses.

 Quote: Why the special focus on the aromatic pyrrole ring? The benzene ring is aromatic too.

Forget about the benzene, it's not getting alkylated any time soon, nor does it have any reason to.

 Quote: As I said, indole can be alkylates, even though it's aromatic. Including at the N position, because the nitrogen atom has only two N-C bonds for all intents and purposes.

For all intensive purposes, there's two N-C bonds most of the time. Sometimes there's three. It's called resonance, because as we agree pyrrole rings are aromatic.
ammonium isocyanate
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Sorry if I wasn't clear with my response. The reason I threw that comment about the benzene ring in was because it sounded to me as if you were saying that indole was aromatic solely because of the pyrrole ring. Again, sorry for the misunderstanding.

Yes, I'm aware of the effect of resonance. However, the nitrogen on the pyrrole ring can be alkylated just the same, after all there's a hydrogen on it that could just as well be an alkyl group. And so in the end, the possibility of 3 N-C bonds in the pyrrole ring is a moot point, as it behaves as having 2 all the time (unless you want to drag pKa into this).

ketel-one
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No it's my fault I wasn't completely correct in what I was saying.

I figured it out, it's not that pyrrole resonates all that much, just that the nitrogen bond with hydrogen is a bit "delocalised" making it harder to alkylate. But I guess it is possible and may be a by-product of whatever 497 was saying.
bbartlog
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Do solutions of salts that form crystalline hydrates typically form more stable supersaturated solutions (ones that are less likely to spontaneously crystallize)? E.g CuSO4 (pentahydrate), Na2SO4 (decahydrate), FeCl2 and so on...
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Pine terpenes

alpha pinene reacts with dry HCl by addition and rearrangement, or by free radical ... I don't know ... to give bornyl chloride.

Where I live, New Zealand, the local pine oil is, apparently, mostly beta-pinene. What is the reaction mechanism and what is the equivalent reaction with beta-pinene?

Thanks.
JohnWW
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Just as a matter of interest, how would that ratio of B-pinene to A-pinene and other terpenes in New Zealand pine needle oil, which I presume is from the very common Pinus Radiata, or Monterey Pine, as distinct from other species, compare with that obtained from trees of the same species in their home areas of Monterey, California, and Isla dos Cedros, México? What variation with climate is observed? What about such trees grown in plantations in Chile, South Africa, and Australia, where the species has also been introduced for timber?

If you are talking about addition of HCl or other halo-acid across a double bond on an hydrocarbon such as that in A-pinene, the Markownikoff rule (1869) would usually be observed, i.e. the H attaches to the carbon that has the fewer alkyl substituents, and the halide attaches to the C with the more alkyl substituents. A mixture of products may occur when both unsaturated C atoms are equally alkyl-substituted.

http://en.wikipedia.org/wiki/File:Beta-pinen.png
http://en.wikipedia.org/wiki/File:Alpha-Pinene_Isomers.svg

[Edited on 14-9-09 by JohnWW]
DJF90
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I ran a xfire search on this when another member asked about alkylation using bornyl bromide I think... Anyways it appeared that both alpha AND beta pinene give the SAME (major) product with HBr, with relative stereochemistries (is this a word?) dependant upon that of the starting material. At least if I remember correctly
Sedit
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1,2-Dibromoethane

1,2-Dibromoethane can be made by the halogenation of Ethylene glycol but I was woundering if there was anything stoping cheep hardware store HCl from performing a simular operation albeit lower yeilding. Lower yeilds from a monetary perspective would be acceptible seeing as batch size could be scaled considerably because I only have 56 grams of NaBr left with 15 grams or so going towards another project. I considered using NaCl+H2SO4 but then got to thinking if it would work in solution as it is.

Anythoughts?

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
ammonium isocyanate
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HCl would probably work if in the presence of AlCl3 as a promoter. I'm not sure if all that water is a problem or not.

Sedit
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The H2O proved to help a bit when I performed the Ethylbromide synthesis by keeping the HBr in solution. Due to HCls lesser solubility its level of fuming can be a bit higher but I don't think the H2O should get in the way of the reaction other then slowing it down to a minor extent due to dilution. AlCl3 seems like a bit much for performing such a synthesis and a simple copper halide catalyst IIRC should work easier then having the need for AlCl3.

Knowledge is useless to useless people...

"I see a lot of patterns in our behavior as a nation that parallel a lot of other historical processes. The fall of Rome, the fall of Germany — the fall of the ruling country, the people who think they can do whatever they want without anybody else's consent. I've seen this story before."~Maynard James Keenan
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 Sciencemadness Discussion Board » Fundamentals » Miscellaneous » The short questions thread (2) Select A Forum Fundamentals   » Chemistry in General   » Organic Chemistry   » Reagents and Apparatus Acquisition   » Beginnings   » Responsible Practices   » Miscellaneous   » The Wiki Special topics   » Technochemistry   » Energetic Materials   » Biochemistry   » Radiochemistry   » Computational Models and Techniques   » Prepublication Non-chemistry   » Forum Matters   » Legal and Societal Issues