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Author: Subject: Another way to 2-Chloroethanol
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[*] posted on 14-4-2003 at 21:37
Another way to 2-Chloroethanol

Normally the way to obtain Ethylene Chlorohydrin, or 2-Chloroethanol, would be by reacting HCl gas with Ethylene Glycol; at least, this is the method NBK presented and which seems to be most widely circulated.

However, this way is tricky, and it requires relatively decent lab equipment, which I have quite a shortage of. So, I have been looking for alternative routes to 2-Chloroethanol, and one which I came along was the Degradation of 1,2-Dichloroethane.

Now, if I recall correctly, 1,2-Dichloroethane is a solvent and a paint stripper...thus providing easy access. Anyhow, certain bacteria in the environment produce an enzyme called "Haloalkane Dehydrogenase." What this does is cleave carbon-halogen bonds. So, the reaction would proceed as follows, starting with 1,2-Dichloroethane.

Cl-C-C-Cl + H2O --> Cl-C-C-OH + HCl

This seems like a very easy method, should we be able to obtain the bacteria.

Here is a site where I found some of my information:
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[*] posted on 15-4-2003 at 07:55

I found this in a search. It sounds like it is possible using that method. I just havn't found any resources for the Haloalkane Dehydrogenase. Maybe someone else has some info or a resource.
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[*] posted on 15-4-2003 at 12:52

I have seen Dichloro Methane aka methylene chloride as a paint stripper but not Dichloro ethane.

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[*] posted on 15-4-2003 at 21:09

I had a quick look in this and if there is no yeaststrain available to do the job - forget it. The bacteria are not to handle - the family this comes from is the tubercel bacteria family, nothing to play with safely.

But chances are good for finding a yeast with equal properties and thats no bigger problem.
Try to find one, I´ll do the same. I have some practical experiences in yeast related biosynthesis - pyruvate decarboxylase/saccharomyces cerevesiae to be exact.

Interesting field with future and possibilities. Applicable if whole cells or cell extract can be used as enzyme separation is usually a pain in the ass and not very effective. (x cofactors and questionable stability of separated enzym are to mention).
Another way is to look if not washing powder or another industry has already the wanted enzyme in use as bulk product. If so, thats the winner of course....
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PHILOU Zrealone
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wink.gif posted on 2-6-2003 at 03:05

Bioremediation chemistry is not as easy as one may think, you need to find the good bacteria and the conditions (pH, temperature, food) optimum for it to decompose the molecule you want it to eat.
Also to high concentration of substrat are toxic and will kill the bacterias ... so 1% is already a lot and you will need purification and fractionisation.
Bacterias often go further than what you wantthem to do...and Cl-CH2-CH2-OH could be degraded further in Cl-CH2-CO2H, CH3-Cl, CH2OH-CH2OH, CHO-CO2H, CH2O, CO2, ...

Thus forget this way!
The best you can do is to allow reaction of
Cl-C2H4-Cl with Fe powder and H2O; the Fe will rust quite fast and chloroethanol aside with glycol will be formed.
The chloration of glycol with HCl and ZnCl2 will provide both CH2Cl-CH2Cl and CH2Cl-CH2OH...the advantage of this method is the ease of separation of the products.
By playing with stoechiometric amounts (1/1 glycol/HCl) you should be able to get nearly only the ethylene chlorhydrine.
Anyway glycol is 100% in water and bp is over 170°C, chloroethanol is soluble in water and boils at 129°C while 1,2 dichloroethane is unsoluble in water and boils at 89°C.
Since the process of halogenation of primary alochols with ZnCl2 requires 100°C at could heat your reactor to 135°C and collect the evolving gas as a mix of H2O/HCl/ClCH2-CH2OH and a little Cl-CH2-CH2-Cl.
Neutralise with Na2CO3 and fractionate by distillation or dehydrate by CuSO4/MgSO4.


By the way I have found in an old book a recipe to make Cl-CH2-CO2H that starts from Cl2C=CHCl and moderate concentration of H2SO4!
Cl2C=CHCl + H2SO4 -H2O/heat-> Cl2CH-CHCl-O-SO4H
Cl2CH-CHCl-O-SO4H -H2O/heat-> Cl2CH-CHCl-OH +H2SO4
Cl2CH-CHCl-OH --> Cl2CH-CH=O + HCl
Cl2CH-CH=O <==> Cl2C=CH-OH
Cl2C=CH-OH + H2SO4 -H2O-> Cl2CH-CH(OH)2
Cl2CH-CH(OH)2 -heat/H(+)-> HCl +ClCH=C(OH)2
ClCH=C(OH)2 <-==> Cl-CH2-CO2H
:o :o :o

PH Z (PHILOU Zrealone)

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[*] posted on 20-10-2006 at 13:44

I've tried and it and it's working:P

Here is the destillation setup, in the addition funnel is ≈70% sulfuric acid, previously used for making conc H2SO4 from 53% HNO3.
The three neck RBF is filled with NaCl and ethylene glycol.

I heated the flask nearly the boiling point of ethylene glycol and slowly added the sulfuric acid, the reaction speed is depending on the acidity, the more acidic the more R-OH are protonated to ROH2+ and thus a good leaving group. So don't add to much sulfuric at one or the flask will boil over, happened twice to me.
The desired product is boiling at 238-130°C, my product came over at 120°C, I think the boiling point was lowered by dichloroethane and the water produced by the reaction.
Tomorrow I'll destill the product fractional over dry CaSO4, the product is quite acidic due dissolved HCl, so I'll add some ethylene glycol with which the free HCl can form some more 2-chloroethanol.

I think I'll fluorinate the pure 2-chloroethanol in my nice copper destill together with some KHF2 to 2-fluoroethanol, I'm somehow scared of it but it would be interesting how toxic the stuff really is.

My nice copper destill:

KHF2 and HF:

PS: On sunday I'll get my own GC-MS system, only have to repair the turbomolecular pump;););););)
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[*] posted on 23-12-2006 at 02:08

Both ehtylene glycol and ethylene chlorohydrin just love to form azeotropes with water and with each other, binary and tertiary, I believe there are multiple azeotropes for some combinations. So drying these and keeping them dry and seperating them is not simply a matter of b.p. You may have to break azeotropes with vacuum (for example), Anyway you should be able to find a reference that lists the known azeotropes of these.

You will find it very hard these days to purchase ethylene dichloride as it has been banned by the UN and an international convention to protect wildlife due to its improper use as a fumigant in certain parts of the world (esp Africa) where the people are too ignorant to use it safely. Where I live, it can no longer be purchased even as a lab reagent. (Neither can chloroform or carbon tetrachloride or ethylene dibromide.)

2-chloroethanol is quite toxic so be careful.

So is 1,2-dichloroethane.

The chlorohydrin is notorious for its use as a backdoor route to thiodiglycol for purposes of making sulfur mustard the German (high cost) way. I assume you have a less nefarious use in mind.
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