Sciencemadness Discussion Board

Synthesis of Diisopropyl-ether

HUNchemist - 11-9-2010 at 10:11

Can someone help me, with this chemical? Can I make it from Isopropyl alcohol and concentrated sulfuric acid? How many degrees? Is it dangerous?
I will be very happy if someone send me a complete synthesis.

(Sorry for my English I'm Hungarian.)

mnick12 - 11-9-2010 at 10:42

Ahhh well you will not get any DIP,
I once was under the same impression as you, that is getting DIP from isopropyl alcohol and sulfuric acid. But you get no such ether mostly propylene and water. But if you want DIP without buying it you could try a williamsons ether synthesis or something like that, though it would be a big waiste of money.

Anyway good luck.

leu - 11-9-2010 at 11:29

From Organic Solvents:

Ethers form peroxides under normal storage conditions. Unless a test shows peroxides to be absent, ethers should not be evaporated or distilled to near dryness. The rate of formation of peroxides in a given ether depends on the storage conditions. Peroxide formation is accelerated by heat, light and air. A small amount of moisture will accelerate peroxide formation in most ethers. Ethers kept in the laboratory should be in a dark bottle in an atmosphere of nitrogen in contact with iron filings or copper powder. Storage in a refrigerator is further recommended.

Peroxide formation in isopropyl ether is rapid. It is advisable to test for peroxide formation, even though it had been freed of them only a short time before.

Unstabilized isopropyl ether readily forms peroxides and may detonate upon shaking. Isopropyl ether can be stabilized by .001% w of dihydric phenols such as pyrocatechol, resorcinol or hydroquinone. Commercial isopropyl ether is usually stabalized with para benzylamimophenol. Peroxides can be destroyed with sulfite solution. Storage in steel containers inhibits the formation of peroxides. Further information on the subject of peroxides in isopropyl ether can be found in J Chem Eng Data, 5, 383 (1960). The preparation of isopropyl ether using ascarite clay catalyst was published in Zh Obshch Khim 19, 348 (1949); CA 44 1006 (1950). Diisopropyl ether has been made from isopropyl alcohol according to the attached patent :cool:

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Formatik - 11-9-2010 at 19:15

Senderens (Compt. rend. 179, 1018; 181, 700) made it by distilling a mixture of same parts isopropanol and 58% pure H2SO4. I don't have this paper and it's in French, so if you want this you'll need to get it on your own.

Allowing diisopropyl ether to stand in an air atmosphere in daylight for several months forms H2O2, isopropanol and a pungent smelling largely volatile mixture of organic peroxides (Clover, Am. Soc. 46, 421).

One of the peroxides formed is triacetone triperoxide, this is very volatile and it can probably crystallize on the inside top of a container, when the screw cap is turned an explosion can result, since it's extremely friction sensitive. I think most noted hazards of explosion involving the peroxide are due to distillations of aged material.

DDTea - 11-9-2010 at 19:41

The alcohol dehydration route, as mnick12 mentioned, is not going to be very effective here. Dehydration by sulfuric acid proceeds by an SN1-type mechanism. There is going to be a competing E1 reaction too, then.

A secondary carbocation, as would be formed from isopropyl alcohol, could go either way: it could undergo a substitution, but just as easily undergo an elimination.

If you do a bit of hand-waving and estimation, though, you could see that the E1 reaction is going to be entropically favorable. Also keep in mind that propylene will be leaving the reaction vessel as soon as it's formed (it's a gas, after all). So, by LeChatelier's principle, more of the E1 product will form.

Anyhow, use the Williamson ether synthesis for this.

leu - 12-9-2010 at 02:09

Isopropyl ether has detonated when a student opened a fresh container from Aldrich and used it in a separatory funnel seriously injuring two fingers that required reconstructive surgery :o It's so dangerous that it shouldn't be considered for use except by very experienced and well equipped workers:cool:

[Edited on 12-9-2010 by leu]

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bbartlog - 12-9-2010 at 05:17

Based on Nicodem's comments in this thread http://www.sciencemadness.org/talk/viewthread.php?tid=13252#...
I would not be so sure that the Williamson ether synthesis is going to be a practical route to DIPE.
When I looked into it briefly it seemed like all the methods with decent yields seemed to involve catalysis at somewhat elevated temperatures (either gas phase or liquids in a pressure vessel), either of propylene+IPA or else acetone (see e.g. 203.199.213.48/1211/1/chidambaram_applied_catalysis_paper.pdf). You should give us some idea of the resources at your disposal and the amount of the ether you need if you want constructive suggestions.

majortom - 13-9-2010 at 09:27

I heard that isopropyl ether was notorious for peroxide formation, supposedly much worse than ethyl. Although why would you want Diisopropyl? It would be almost useless for any of the usual applications ethers are used for. I don't think it would be any help with grignard reagents, I mean that oxygen looks way too sterically hindered to coordinate the magnesium section.

And anyway, what uses do ethers have except as a solvent or part of some other compound? Why not just use a much cheaper hydrocarbon?

But I was thinking of this if you really wanted it, why not just reflux it in a standard Lucas reagent mixture to get isopropyl chloride and then do a Williams ether synthesis as another poster said? If you really wanted to do it fast and make it reactive you could reflux it with HI or HBr and maybe add the corresponding zinc halide as in a lucas workup.

Of course the real problem is the alkali metal you would need to make the alkoxide for the other section of the process, which of course would lead you to some really expensive ether, and for the amateur alkali's are either prohibitively expensive (lithium from batteries, or sodium for 10 bucks a gram off some site) or very hard to get at any reasonable quantity(explosivemetals.com has some pretty cheap per gram, if you want a pound of it). And even then it is not cheap. It probably wouldn't endear your to our friends at the police department either.

I haven't tried it but it looks promising, I have heard that if you get an transition metal halide, suspend it in anhydrous alcohol, and run a current through it. Apparently it makes your alkoxides for you, I suspect it might be tricky though. If you do that you might be able to turn something like an iron alkoxide into a more useful varient or possibly use it straight with a more reactive halide species.

Anyway that is just speculation.

[Edited on 13-9-2010 by majortom]

madscientist - 14-9-2010 at 12:19

It is possible to achieve reasonable yields of diisopropyl ether via the acid catalyzed route. Apparently the key is to use H2SO4 of a concentration no greater than 60%, a molar ratio of the alcohol to the acid of at least 4:1, and pressure. See US2178186.

Anders2 - 15-9-2010 at 17:53

Isobromopropane might react with anhydrous Isopronanol to make the Ether.
bromopropane could be made analogous to iodomethane synthesis in the "prepublication" section, with the exception that it would have to stay chilled, being a gas at rt.

bbartlog - 15-9-2010 at 18:59

Quote:
Isobromopropane might react with anhydrous Isopronanol to make the Ether


Why would it do that? I assume you are suggesting that HBr would be one of the products along with the ether, but since HBr reacts with isopropanol to make 2-bromopropane I don't think this reaction runs in the direction you are proposing.
Quote:
being a gas at rt


Also no.

Anders2 - 16-9-2010 at 19:46

Wow, bromopropane supposedly has a much greater liquid range than water! So much for water being "unique" in its liquid range. Yes, HBr reacts with Isopropanol, but a perhaps mixing in propylamine would pull out the HBr as the salt. The reaction would likely be very slow.

entropy51 - 17-9-2010 at 16:26

Quote: Originally posted by Anders2  
Wow, bromopropane supposedly has a much greater liquid range than water! So much for water being "unique" in its liquid range. Yes, HBr reacts with Isopropanol, but a perhaps mixing in propylamine would pull out the HBr as the salt. The reaction would likely be very slow.
Quote:
I will not make any more speculative posts here.
I would like to point out that I did nothing wrong. My posts happened not to be liked by the administrator and a few others. I had sent an earlier message to Pulverone to this effect, but did not get a reply. After being initially banned, I refrained from making specualtive posts in the Energetics section, and only started one new topic, in the Organics section.
I can see that this forum does not value potentially useful ideas, even when the poster tries to reference as much as possible, and draw parallels with other reactions already scientifically documented.
I am still unsure as to what, exactly, was done wrong.

niertap - 11-9-2012 at 22:03

slightly old thread, but something new and constructive to add

It seems feasible to make diisopropyl ether(DIPE) from isopropanol, acid, and heat.

I think the synthesis with Isopropanol/sulphuric acid fails because H2SO4 is so strongly dehydrating.

It might be possible to distill it off of a mixture containing 91% isopropanol with ~10% HCl added. DIPE has a 10C lower boiling point and doesn't really form hydrogen bonds. Sterics seem like they would hinder the reverse reaction of acid cat hydration of DIPE. The reasonable amount of water combined with strong acidity of HCl would probably cause a reasonable hydration of propene.


Adding conc acetic acid to the isopropanol/HCl might also help. The propylacetate ester could fairly easily form and the acetate could easily be protinated, which isopropanol could attack and make the ether.

isopropacetate bp 89C 4.3% solubility in water
isopropanol bp 82.5C
DIPE bp 68.5C 1% solubility in water

zed - 12-9-2012 at 12:29

Seems like Sodium Isopropoxide should react with 2-Bromopropane to produce the desired ether.

But let me digress. Why do you want to make Diisopropyl ether?

You aren't another one of those pesky terrorist types, are you?

bbartlog - 13-9-2012 at 16:57

Quote: Originally posted by niertap  

It seems feasible to make diisopropyl ether(DIPE) from isopropanol, acid, and heat.

I think the synthesis with Isopropanol/sulphuric acid fails because H2SO4 is so strongly dehydrating.

It might be possible to distill it off of a mixture containing 91% isopropanol with ~10% HCl added.


Count me skeptical. I've noodled around with a few variations on isopropyl chloride synthesis (mostly with rather poor results), almost all of which involved HCl plus IPA and eventual reflux and fractional distillation. I don't recall seeing any significant fraction come off at the bp of the ether.

SM2 - 14-9-2012 at 12:28

If I'm not mistaken, there was a thread a few years back which lauded the quality of the IPE high. It was supposed to be way better than even ket. I'll do some reseach, see what I can find.

zed - 15-9-2012 at 11:29

Well, huffing ain't great, but it's more ethical than blowing people up.

6dthjd1 - 27-9-2022 at 02:17

does anyone have the Senderens (Compt. rend. 179, 1018; 181, 700) paper?