Sciencemadness Discussion Board

Ethylchloride preparation

Per - 26-1-2007 at 10:30

I want to make some C2H5Cl, I know a praparation for it but in this preparation you need ZnCl2, but I haven´t any yet.

My question is, if I can make it also by just introduce HCl gas in C2H5OH with following destillation of the C2H5Cl?

Have anybody any ideas to make the yield higher, for example, is it good to add 98% sulfuric acid to the C2H5OH?


My english is not the best, when I made a big mistake, please tell me;)

12AX7 - 26-1-2007 at 10:48

For sure, you have to be careful about not making ethylene or diethyl ether, two common products of EtOH + H2SO4 + heat.

In terms of esterification it should work, but I think there's a reason why it doesn't.

If you're going to "introduce HCl gas" and need ZnCl2, why not add zinc shavings while adding HCl?

Tim

Per - 26-1-2007 at 10:58

Quote:
Originally posted by 12AX7
For sure, you have to be careful about not making ethylene or diethyl ether, two common products of EtOH + H2SO4 + heat.


Yes your right, but preparation of ether needs 140°C and distillation of EtCl needs only 12°C. So I don´t think that EtOh and H2SO4 wuold react.

I don´t even have any Zink here, not the metal and no compound.

[Bearbeitet am 26-1-2007 von Per]

12AX7 - 26-1-2007 at 11:02

Say what?

Per - 26-1-2007 at 11:07

I´m new here and I made a little mistake, but I edited already.

Nicodem - 26-1-2007 at 11:50

Unlike the hydrobromic or hydroiodic acids, the hydrochloric acid is not acidic enough to protonate ethanol efficiently enough for the nucleophilic substitution to occur at a practically useful rate. ZnCl2, which is a strong acid itself, also complexes with HCl to form an even stronger acid. Additionally ZnCl2 increases the concentration of chloride anions in the reaction mixture. Both effects contribute in a way to increase the rate of the reaction very much, so ZnCl2 catalyst is necessary.
I can't believe you can not obtain such a common metal as zinc!
The only way to avoid using a Lewis acid catalyst would be to heat a saturated solution of HCl in ethanol to above 100°C in order to increase the reaction rate. Needles to say that you would need a pressure resistant vessel (10 bar at least).

Also, please use the search engine before posting old questions:
http://sciencemadness.org/talk/viewthread.php?tid=6617#pid75...

Ozone - 26-1-2007 at 16:22

I have gotten significant yields of diethyl ether from ethanol catalyzed with H2SO4 sealed and heated to ~105°C for about 4hr. This can significantly lower ester yields as the ether formation is competitive.

For some real fun, try to store your ethyl chloride in an Al° vessel:o.

O3

garage chemist - 26-1-2007 at 20:21

Even Isopropyl chloride, which is significantly easier to form than ethyl chloride because secondary alcohols are esterified much easier than primary alcohols, requires ZnCl2 in its preparation (though much less than with ethyl chloride, about 0,1 mol ZnCl2 for 1 mol Isopropanol and 1,5 mol HCl is enough if distilled very slowly through a column).
So with ethanol, no chance to go without it.
You have to order or make ZnCl2 before you can make ethyl chloride.

guy - 26-1-2007 at 20:32

Is there a reason why zinc chloride is used as opposed to ferric chloride? Is it just more cost efficient?

garage chemist - 26-1-2007 at 20:53

Only the hexahydrate is cheap and available, the necessary anhydrous substance (only this has the required lewis acid activity) is a nasty fuming solid that reacts vigorously with water, like AlCl3. It can also only be made from the elements or from anhydrous HCl, not from the hydrate. Therefore it can not be recycled.
Also, I think it gets inactivated in water like AlCl3 due to the formation of the iron(III)hexaaquo complex.

guy - 26-1-2007 at 21:12

You can make anhydrous zinc chloride from the hydrate? I didnt know that, I thought it would form an oxychloride. I guess that is good news then.

Per - 27-1-2007 at 02:29

It´s possible to make dry ZnCl2 when you heat the hydrate and sublimate it following.
But be careful, when you heat it too strong it would envolve HCl gas and the solution would get brown.

I havent any zinc yet because the tubes I can buy have just a small zinc coat.
So I have to buy some ZnO from a chemical shopp.

Sauron - 27-1-2007 at 05:54

As previously reported on this forum (see Search) alkyl chlorides are readily formed from alcohols by the action of cyanuric chloride (CC) also known as 1,3,5-trichloro-s-triazine (TCT) which is a cheap agrochemical intermediate and totally unregulated.

The journal articles on this have been posted before.

The ethanol should be anhydrous, otherwase you waste some reagent.

You will need very efficient cooling to condense the EtCl. Ice-salt or dry-ice-acetone.

This is a much easier and better prep than mucking around with ZnCl2.

NB do not confuse TCT with TCCA (trichloroisocyanuric acid.) In the former the chlorines are attached to carbon, in the latter, they are attached to nitrogen.

[Edited on 27-1-2007 by Sauron]

garage chemist - 27-1-2007 at 06:20

Unfortunately Cyanuric chloride is labeled as "Very toxic" (T+) in europe, which makes it damn hard to get and also expensive because one has to buy from the overpriced chemical suppliers through e.g. pharmacies.

Per - 27-1-2007 at 06:21

[img]For some real fun, try to store your ethyl chloride in an Al° vessel.[img]
I don´t know what happened then but I can imagine:D

Follows should also be fun:
NaNO3 + C2H5Cl > NaCl + C2H5NO3

Sauron - 27-1-2007 at 06:56

@GC, how unfortunate.

The CC i buy comes from Europe but fortunately in Thailand it is not at all restricted. What about in Switzerland?

Ozone - 27-1-2007 at 07:49

3 Me-Cl + Al° --> AlCl3 + Me3Al.

A supplier screwed up and sent us 3 10kg tanks of MeCl. The problem was that the tanks were Al, rather than stainless as prescribed. This was determined when a tank was opened and immediately became a flame-thrower. Fortunately, at the time, I was given the option of disposing of the material;). It was around new years, and a pigtail was affixed (to the tank) with *amazing* results:D.

TCCA is OTC here as pool chlorinating tablets; it seems like they work fine as-is, but are rather difficult/noxious to powder.

12AX7 - 27-1-2007 at 08:44

Odd, I've used zinc chloride as flux before. It seems to boil a lot (being a fully liquid solution), then fuse to a sort of glassy material, which I suppose is zinc chloride plus oxides and impurities (especially iron oxide, being what I was soldering).

Tim

Nicodem - 27-1-2007 at 11:30

Quote:
Originally posted by Per
Follows should also be fun:
NaNO3 + C2H5Cl > NaCl + C2H5NO3

You can not obtain ethyl nitrate this way. The nitrate anions are not nucleophilic enough for such an reaction to occur in practice. If it is ethyl nitrate that you want than just esterify ethanol with nitric acid. I'm quite sure there are a lot of posts about such esterifications on this forum, especially in the "Energetic Materials" section (just UTFSE).

chemrox - 27-1-2007 at 21:51

Can the Lewis acid, ZnCl2, be made in situ with the metal and acid? I think he asked that earlier?

garage chemist - 28-1-2007 at 00:33

Does anhydrous aluminium chloride react with alcohols?
I read in the thread on methyl iodide preparation that MeI has been successfully prepared from iodine, Al and methanol. That means that AlI3 reacts with alcohols to produce the alkyl iodides, which would be really convenient if AlCl3 does the same thing.
AlCl3 is not too expensive and reasonably easy to obtain.

(is this the case in Bangkok too?)

Per - 28-1-2007 at 01:19

I don´t remember if I asked that, but you can made it in this way, just drying should be a Problem.

NaNO3 + C2H5Cl > NaCl + C2H5NO3
I thought that this preparation should work because NaCl is a very strong compound and because this works well:
NaNO3 + HCl > NaCl + HNO3

I wanted the Ethylchloride for something else than just C2H5NO3.
I think destillation of C2H5NO3 is to dangerous for me, so I thought I could get it also with Ethylchloride.

I don´t understand the thing with the TCCA, I can also buy it as pool chlorinating tablets, it is possible to make Ethylchloride with TCCA?

Nicodem - 28-1-2007 at 04:01

Quote:
Originally posted by Per
NaNO3 + C2H5Cl > NaCl + C2H5NO3
I thought that this preparation should work because NaCl is a very strong compound and because this works well:
NaNO3 + HCl > NaCl + HNO3

Actually the two equations you wrote have absolutely nothing in common. The first one is supposed to be a SN2 reaction, while the second is a ionic equilibrium (thus you should write it according to the proper conventions).
Quote:
I don´t understand the thing with the TCCA, I can also buy it as pool chlorinating tablets, it is possible to make Ethylchloride with TCCA?

Not directly. Trichloroisocyanuric acid is a powerful oxidant. I don't know how its mention came into this thread but someone probably confused it with cyanuric acid chloride, an acid chloride that can be used for preparing other acid chlorides and alkyl chlorides from alcohols. The two compounds are often confused though being of completely different chemistry.
Quote:
Originally posted by garage chemist
Does anhydrous aluminium chloride react with alcohols?

Following the link I gave in my previous reply, you will get to a paper discussing a related issue about the efficiency of several Lewis acids in the chloride substitution of the alcohols. As far as I can remember the authors concluded that of FeCl3, ZnCl3 and AlCl3 the ZnCl2 is the best catalyst with the use of HCl. I do know ZnCl2 itself does not solvolize in primary alcohols, but AlCl3 certainly should as it is a way stronger acid. But probably the conversion would not be quantitative like in the case of AlI3, and side products like ethene might be an issue to consider. I guess it is worth trying if you have AlCl3 to waste or if you wish to form it in situ.

Per - 31-1-2007 at 05:32

I heared that it should also possible to prepare C2H5Cl with AlCl3*6H2O.

Can that be possible?

Nicodem - 31-1-2007 at 11:01

No.

Per - 31-1-2007 at 11:59

Ok.

garage chemist - 2-2-2007 at 08:53

Ethyl chloride is apparently still available in pharmacies as a local anesthetic ("ice spray", though all of the metal icespray-cans contain something different today). You have to ask specifically for Chloräthyl.
Also enter Chloräthyl into google- you will find common prices for 100ml of it in pharmacies (around 5€).

This would also be a good idea for nitroethane preparation.
You just have to react it with silver nitrite.

Per - 3-2-2007 at 05:45

Why doe´s the preparation of nitroethan work with silver nitrate and why doesn´t work it with sodium nitrate?
I can´t imagine that.

Looking for Chloräthyl seems to be a good idea, thank you.

last time I tried to prepare ethyl chloride by adding a 25%HCl solution to a mix of ethyl alcohol and konz. H2SO4.
I heated it a little bit and it envolved white gases, I tried to condense them but it does not work, not even with a ice-alcohol mix.

Nicodem - 3-2-2007 at 08:26

Quote:
Originally posted by Per
Why doe´s the preparation of nitroethan work with silver nitrate and why doesn´t work it with sodium nitrate?
I can´t imagine that.

I don't know where you heard that nitroethane can be made with silver nitrate, but you can be sure you got it wrong. Silver nitrate and ethyl chloride in DMF or other dipolar solvents would give you ethyl nitrate and not nitroethane. With sodium nitrate you would get no reasonable reaction due to the already mentioned too low difference in the chloride/nitrate nucleophilicity (this problem is overcome in the case of silver salts by the formation of the highly insoluble silver halides – this drives the reaction forward). As already mentioned by Garage chemist, for the preparation of nitroethane from ethyl chloride you would need silver nitrite (AgNO2, also know as silver nitrate(III) as opposed to the nitrates which are salts from the nitrate(V) ion that is NO3(-)).
Though the nitrite anion is way more nucleophilic than the nitrate anion it still requires better leaving groups like the bromide or iodide. Ethyl chloride might give a small yield of nitroethane even with NaNO2 if an optimal solvent is used, but it might also give a lot more of the side product, ethyl nitrite, which tends to condense with nitroethane thus destroying it. I would dare to say that the only reasonable way of preparing nitroethane from ethyl chloride is by using silver nitrite, but on the other side any reasonable person would rather use ethyl bromide or ethyl iodide anyway. Not only because they are several thousand times more reactive, but also because they are much more easy to prepare (or buy given that they are liquids).
Quote:
last time I tried to prepare ethyl chloride by adding a 25%HCl solution to a mix of ethyl alcohol and konz. H2SO4.
I heated it a little bit and it envolved white gases, I tried to condense them but it does not work, not even with a ice-alcohol mix.

The white fume was moist hydrogen chloride gas. Hydrogen chloride only condenses bellow -85°C at normal pressure.

Per - 3-2-2007 at 11:42

Quote:
Quote:
The white fume was moist hydrogen chloride gas. Hydrogen chloride only condenses bellow -85°C at normal pressure.

I feared that, so it is proved that the method with H2SO4 does not work at all.

Random - 15-2-2011 at 11:56

Is it possible to use 36% ethanol and zinc chloride solution in HCl(aq) to make ethyl chloride or I need to have anhydrous reagents?

Per - 15-2-2011 at 13:56

wouldn't give a reasonable result, but ethanol is OTC as spirit with 94% ethanol. also is't recommended to use anhydrous ZnCl2 and dry HCl.

bbartlog - 15-2-2011 at 16:27

I've only done this with IPA (to make 2-chloropropanol), but I think 36% alcohol plus aqueous HCl will give you way too much water for the reaction to proceed. Ideally (to maximize yield) you would want dry HCl gas bubbled into dry ethanol with anhydrous ZnCl2. But unlike some reactions (say, Grignard reagent preparation) you can have some water and still get results. Still at a minimum I would suggest 95% ethanol and anhydrous ZnCl2; you would then have a chance with aqueous HCl. Alternatively, 95% ethanol plus ZnCl2 hydrate plus HCl gas would probably also be dry enough

~Anthrax~ - 16-2-2011 at 11:36

Unless I'm missing something obvious, surely ethylchloride (chloroethane) can be made from ethanol and phosphorus pentachloride?

CH3CH2OH + PCl5 -----> CH3CH2Cl + POCl3 +HCl

~Anthrax~

Random - 16-2-2011 at 14:40

Thanks for the responses, maybe I will try it on test tube scale with those reagents though to obtain even small yield, just to get some experience with that stuff. After that I will try anhydrous ZnCl2, 96% ethanol and 19% HCl(aq).

@Anthrax

http://www.ucc.ie/academic/chem/dolchem/html/comp/ethanol.ht...

Quote:
Halogenation or Substitution of Ethanol with PCl5
Ethanol reacts with phosphorus pentachloride at room temperature to form hydrogen chloride, ethyl chloride (i.e. chloroethane) and phosphoryl chloride.


C2H5OH + PCl5 ==> C2H5Cl + POCl3 + HCl
Ethanol Phosphorus Ethyl Phosphorus Hydrogen
Pentachloride Chloride Pentachloride Chloride


It should be possible.




[Edited on 16-2-2011 by Random]

Sedit - 16-2-2011 at 15:24

Random a test tube scale will more then likely provide little information and be dishearting. I tryed the same with EtBr and got nothing from a test tube scale while I got greater then 75% IIRC performing the synthesis at a one mol scale. I feel its a synthesis of inherited losses and a test tube does not produce enough to cover those losses.

Random - 17-2-2011 at 13:10

Thanks for that information, it would be actually dissapointing to see that test tube scale produces nothing and then loose will to try bigger scale :)

Nitro-esteban - 8-6-2013 at 06:15

I mixed 12.5 grams of 80% ethanol with 27.3 grams of 29% HCl and then added a few ml of a concentrated ZnCl2 solution and nothing happened!

Fantasma4500 - 26-8-2013 at 03:40

well ofcourse, nitro-esteban..
this reaction relies on anhydrous(-ness?)
so not having it all anhydrous does obviously not work

one approach by what i read here would be H2SO4 98% + NaCl > anh. HCl (g)

anh. HCl(g) + Zn (s) + EtOH (aq) > anh. ZnCl2 (which then reacts with the EtOH to form EtCl)
i dont see anything pointing away from also using Cl2 gas
in which i have discovered can be generated relatively slowly but in high concentration by Na2Cr2O7 + HCl (probably many other dichromates would work, this is because i store dichromate stored in liquid with HCl in a glass bottle)

i must say, tho 'Per' probably isnt around the forum anymore, zinc is very easy to get a hold of
its used for fishing weights, anti corrosion blocks for boats, gutters, car wheel balance pieces, heavy duty battery casings,

foxofax474 - 15-3-2024 at 08:41

Quote: Originally posted by Fantasma4500  

one approach by what i read here would be H2SO4 98% + NaCl > anh. HCl (g)

anh. HCl(g) + Zn (s) + EtOH (aq) > anh. ZnCl2 (which then reacts with the EtOH to form EtCl)


Does this method produce EtCl in dissolved in the EtOH or does it bubble out as a gas?

clearly_not_atara - 15-3-2024 at 10:50

According to Raoult's law, the product is most likely a gas, since the rxn is sluggish at low temperatures.

My suggestion: don't make ethyl chloride. Alkylating agents are a very bad starting point for someone new to chemistry.