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Picric-A
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I have looked this reaction up and noted i need ethyl iodide/bromide, not chloride.
I have one question though which remains unanswered. Surely you can choose what product to obtain by varying the ratios of the product, so for every
mole of 2-aminoethanol use 2 moles of ethyl bromide... is there a problem with this?
According to the properties;
Mono;
Density 0.91
Melting point -6 ºC
Boiling point 167 ºC
Refractive index 1.439-1.441
Flash point 78 ºC
Water solubility miscible
Di;
Density 0.884
Melting point -70 ºC
Boiling point 161 ºC
Refractive index 1.44-1.442
Flash point 51.5 ºC
Water solubility soluble
the monoethylaminoethanol can be frozen out, like with the mononitrotoluenes, yielding pure diethylaminoethanol.
[Edited on 3-8-2009 by Picric-A]
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garage chemist
chemical wizard
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The alkylation will go to the quaternary ammonium salt as well. You will inevitably get a mix of ethanolamine, N-ethylethanolamine,
N,N-diethylethanolamine and N,N,N-triethylethanolammonium salt, along with alkali halide byproduct.
Freezing out is useless as a separation method here. Such mixes are generally fractionated. And this one is going to be hard.
If you're so interested in 2-chloroethanol that you made a thread about it, then make this compound and prepare ethylene oxide from it. Then react it
with diethylamine. N,N-diethylethanolamine is the only product of this reaction if you keep diethylamine in excess (introduce the EO into diethylamine
in a solvent). This is how to do it.
Make the diethylamine from ethyl halide (2 mol) and ammonia (1 mol) in presence of 2 mol NaOH. Again, you get a mix of ammonia, ethylamine,
diethylamine and triethylamine if you basify the mix afterwards and distill everything that boils below 100°C.
Now, the catch is that the boiling points of the three ethylamines are far enough apart to make fractionation relatively simple. You will have no
problem obtaining a sufficient amount of diethylamine this way.
And triethylamine contamination in your diethylamine is not of any concern, since EO doesn't react with it.
If you wanted to do a really good job with the diethylamine isolation, you could do the Hinsberg separation, which allows quantitative separation of
short-chain alkylamines without any fractional distillation or crystallization whatsoever.
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cal
Hazard to Self
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This compound 2-chloroethanol can also be used to make Diethanolamine via ethylene oxide:
Quote: Originally posted by garuda  | Notwithstanding the public domain ststus of the Gomberg paper, the fact remains that the topic is not mustard gas but 2-chloroethanol (ethylene
chlorohydrin).
When Saddam Hussein was prevented from importing thiodiglycol to feed Chemical Ali's mustard plants, they switched to 2-chloroethanol and made their
own thiodiglycol a la Gomberg.
A lot of people were injured, blinded, killed and who knows how many more will suffer delayed carcinomas because sulfur mustard is a potent
carcinogen.
So do not call entropy's actions "mimja editing". instead consider the abject irresponsility of your own actions, polverone, and allow entropy51 to
see to his own karma as best he can. I applaud his self-restrainst. What does the preparation of a compound that crosslinks the strands of DNA and
prevents replication and repair, have to do with amateur chemistry?
It would have been better to extract the chlorohydrin info from the paper and publish only that.
Anyway Gomberg is obsolete for either product. |
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Dr.Q
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So i tried to make chloroethanol from bubling HCl gas through etyleneglycol at 100 'C.
The system that i had set up was pretty much like in the pic.
In the left flask HCl was generated by H2SO4+NaCl(solution) . In the middle flask there is pure etylene glycol.
Now here is the problem. Everytime i try bubling , it vacuums etylene glycol to HCl generator. I cant fix it. Because of it vacums i cant efficently
bubling the gas.
Why it vacums , what could be the problem ?
[Edited on 30-6-2013 by Myeou]
[Edited on 30-6-2013 by Myeou]
[Edited on 30-6-2013 by Myeou]
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Nicodem
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| Quote: Originally posted by Myeou | Now here is the problem. Everytime i try bubling , it vacuums etylene glycol to HCl generator. I cant fix it. Because of it vacums i cant efficently
bubling the gas.
Why it vacums , what could be the problem ? |
HCl is extremelly rapidly and exothermically absorbed in ethylene glycol, so it is not possible to avoid suck-backs if you introduce it bellow the
surface. On the other hand, there is no need to do that. Just introduce it above the surface. It will be equally well absorbed, but without the
suck-back problem. Though, you need to use a stirrer, like a magnetic one. With bubbling you also get the mixture agitation, but if you introduce a
gas from above the surface, you need to use a stirrer to compensate. Once the air is purged out of the system, the absorption is just as effective.
Be careful with chloroethanol. Genotoxic substances should be treated with great care even when there is no definitive evidence of carcinogenicity,
especially if they are as toxic as chloroethanol. Also, beware that treating chloroethanol with bases produces the volatile, carcinogenic and very
toxic ethylene oxide.
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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sonogashira
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You could add an in-line non-return valve where you have the rubber connector.
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Agricola
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For a preparation of 2-chloroethanol (ethylene chlorohydrin) from hydrogen chloride and ethylene glycol, see the attached paper by Ladenburg. The
document is in German, use Google Translator if necessary.
The procedure is analogous to the one below, in English:
http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=cv1...
For a volumetric determination of 2-chloroethanol, see the paper by Uhrig, in English.
Attachment: chlorohydrin_ladenburg1883.pdf (155kB)
This file has been downloaded 778 times
Attachment: chlorohydrin_uhrig1946.pdf (156kB)
This file has been downloaded 1068 times
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PHILOU Zrealone
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I have long time ago thought about this because following me chloroethanol is a must have organic reagent/chemical.
There are in fact two options to get to chloroethanol... the first one everybody thinks about; and the second one by thinking in a reversal fashion.
1°) HCl + HO-CH2-CH2-OH --ZnCl2--> Cl-CH2-CH2-OH + Cl-CH2-CH2-Cl + H2O
2°) Cl-CH2-CH2-Cl + NaOH --H2O--> Cl-CH2-CH2-OH + HO-CH2-CH2-OH + NaCl
Then separation by fractionnal distillation thanks to the fact BP glycol >> BP chloroethanol >> BP dichlorethane
Thanks to fractionnal distillation and both reaction the theorical yield of chloroethanol can be set very close to 100%.
[Edited on 6-11-2013 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
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Agricola
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PHILOU Zrealone, the second reaction will make a mess.
When you are mixing the reagents, one will be in excess. If an excess of NaOH is present, you will have mostly ethylene glycol. You can keep NaOH
always in excess and get a good yield of ethylene glycol if your reaction conditions don't turn the ephemeral ethylene chlorohydrin intermediate into
ethylene oxide before it turns into ethylene glycol.
If an excess of 1,2-dichloroethane is present, when the amount of ethylene chlorohydrin becomes considerable, yet still small, then some of the NaOH
will eat some of the ethylene chlorohydrin and form ethylene glycol, thus preventing the accumulation of ethylene chlorohydrin. Adding more NaOH will
just make a chemical soup of 1,2-dichloroethane, ethylene glycol, and ethylene chlorohydrin. Reaction conditions may also turn some of the ethylene
chlorohydrin into ethylene oxide.
The heat of the distillation will help the CH2-OH negative oxygens react with the CH2-Cl positive carbons, replacing the latter's chlorines. This will
go on and on creating a chemical monster. Separation by another method before distillation would be necessary to get a low yield of ethylene
chlorohydrin.
The standard procedure is Ladenburg's. There is also another one, more economical on a technical scale, by Gomberg, based on the reaction of chlorine
and ethylene in water.
Last but not least, there is another way to make ethylene chlorohydrin, shown on Vanino's Handbuch, available on S. C. Wack's Media Fire folder. It
uses S2Cl2 and ethylene glycol and is easy to carry out (shake two liquids then apply heat). It is analogous to the procedure employed by Morley. For
the preparation of S2Cl2 see Vanino's Handbuch or Biltz's Laboratory Methods, also on S. C. Wack's Media Fire folder.
Attached to this message is a print version of the Organic Syntheses preparation analogous to Ladenburg's, and the papers by Gomberg and Morley.
[Edited on 6-11-2013 by Agricola]
Attachment: chlorohydrin_gomberg1919.pdf (1.2MB)
This file has been downloaded 1228 times
Attachment: chlorohydrin_marvel1928.pdf (116kB)
This file has been downloaded 692 times
Attachment: chlorohydrin_morley1885.pdf (155kB)
This file has been downloaded 831 times
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byko3y
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chlorohydrin_ladenburg1883.pdf
German:
Die bekannten Methoden zur Darstellung von Chlorhydrinen liefern theils mangelhafte Ausbeuten, theils sind sie unbequem in der Ausführung, oder sie
geben, wie die Methode von Carius mittelst Glycol und Chlorschwefel, meist ein unreines schwefelhaltiges Produkt.
Das folgende Verfahren, das sich in meinem Laboratorium bei der Darstellung von Chlorhydrinen vielfach bewährt hat, ist eine Modifikation der von
Wurtz in seiner berühmten Abhandlung über die Glycole angegebenen Methode. Ich werde sie hier für die Gewinnung von Aethylenchlorhydrin
beschreiben. Herr Dr. Berend hat dieselbe auch zur Darstellung von Trimethylenchlorhydrin verwerten können, worüber er später selbst berichten
wird.
Glycol wird in einem Destillationsapparat auf 118°C erhitzt und gleichzeitig ein langsamer Strom trockner Salzsäure hindurchgeleitet. Das gebildete
Wasser und Glycolchlorhydrin destilliren ab und werden in tubulirten Vorlagen aufgefangen. Nach und nach wird die Temperatur des Bades bis etwa
160°C gesteigert, wo dann bis auf einen unbedentenden Rückstand die angewandte Glycolmenge vollständig zerlegt wird. Bei der Verarbeitung von 100g
Glycol sind etwa 16 Stunden nöthig.
Das Destillationsprodukt wird mit dem 2-3 fachen Volum Aether versetzt und durch Kaliumcarbonat zunächst von vorhandener Salzsäure befreit. Dann
wird die ätherische Lösung abgesaugt und über frisch geschmolzenem Kaliumcarbonat vollständig getrocknet. Zwei Destillationen liefern ein reines
zwischen 128°C und 131°C siedendes Produkt und zwar etwa 60 pCt. der theoretischen Ausbeute.
English:
The known methods for the preparation of chlorohydrins deliver partly poor yields, and partly they are uncomfortable in the execution, or specify how
the method of Carius means Glycol and sulfur chloride, usually an impure sulfur-containing product.
The following procedure, which has proved in my laboratory in the preparation of chlorohydrins often, is a modification of in his famous treatise
given by Wurtz on glycols method. I'll describe them here for the recovery of ethylene chlorohydrin. Dr. Berend has the same also can use to display
Trimethylenchlorhydrin what he will tell himself later.
Glycol is heated in a distillation apparatus to 118°C while passing a slow flow of dry hydrochloric acid. The water and Glycol chlorhydrin formed
from distil and are collected in tubulated templates. Gradually, the temperature of the bath is increased to about 160°C, which then except for a
dent without end residue of glycol which is used completely dismantled. When processing 100g glycol are about 16 hours necessary.
The distillation product is mixed with 2-3 times its volume of ether and first freed by potassium of existing hydrochloric acid. Then the ethereal
solution is aspirated and completely dried over freshly melted potassium. Two distillations deliver a pure between 128 ° C and 131 ° C boiling
product and that about 60 per cent. of the theoretical yield.
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