Sciencemadness Discussion Board

How to synthesize cetyl chloride

Cheisenberg - 2-11-2017 at 00:34

Hello everyone, I would like to make cetyl (hexadecane) chloride in lab, but I don't want to use thionyl chloride. Can I use hydrochloric acid? I know that it's difficult to chlorinate long chain alcohols with HCI, maybe with some catalyst, I don't know. If anyone can help me, I'll be glad :)

JJay - 2-11-2017 at 07:21

Hydrochloric acid reacts very slowly with primary alcohols. You could use phosphorus trichloride or perhaps phosphorus pentachloride, or you could brominate it with hydrobromic acid or even just sulfuric acid and sodium bromide. Cetyl bromide is usually more useful than cetyl chloride, but if you need cetyl chloride for some reason, there might be an easy way to swap out the bromine for chlorine... I'm not sure offhand.

Cheisenberg - 3-11-2017 at 04:29

Thank you JJay for your reply.
I don't want to use derivatives of phosphorous to.
I have researched for this synthesis that is chlorinating with HCI in everywhere, maybe there is a way to synthesize like this, but I couldn't find.
There are generally things that about short chain ones.

I wonder that if I use sulfuric acid and sodium chloride together to chlorinate cetyl alcohol as what you said about Br, can I make it? Maybe I can synthesized this with pure HCI, which will be obtained.

Thanks again.

SWIM - 3-11-2017 at 05:20

What about Lewis acids like Zinc or aluminum chloride?

With those you could use a solvent more able to keep the alcohol in solution.

LearnedAmateur - 3-11-2017 at 12:24

Lucas' reagent (equimolar conc. HCl + ZnCl2) can be used to chlorinate alcohols. As already mentioned, primary alcohols react slowly, but it can be accomplished through reflux. I'm not sure on the exact conditions and times required, but the product should not be miscible with water so extraction is easy, at worst you'll have a turbid solution which can be distilled.

JJay - 3-11-2017 at 12:43

It looks like Lucas cited this paper in his paper on the Lucas reagent (found on Google Scholar; which led me to the Vespiary, haha). It gives a procedure for obtaining cetyl chloride in 65% yield.

Attachment: alcohols2halides.hcl-zncl2.pdf (344kB)
This file has been downloaded 445 times


[Edited on 3-11-2017 by JJay]

Cheisenberg - 6-11-2017 at 04:17

Thank you everyone.

I didn't try lewis acid. You're right. It can work.
I have downloaded document, I will try.
65% yield is not bad.

Thanks guys, I'll be back with results :)

VSEPR_VOID - 9-7-2018 at 22:46

Still waiting for those results

Chemi Pharma - 14-7-2018 at 06:09

As already mentioned by me at another topic: http://www.sciencemadness.org/talk/viewthread.php?tid=80658&... , alkyl chlorides can be achieved from any kind of primary, secondary, terciary or benzylic alcohols, with TCCA and Triphenylphosphine. Archive attached below.

Other way, without the use of nasty and hard to get thionyl chloride or PCl3, PCl5 or POCl3 either, you can get the chloride from alcohol reacting the late with Cyanuric chloride and DMF in dichloromethane media, as attached below:

both methods will give you high yields, as you can read at the papers.





Attachment: Alcohols to Chlorides with cyanuric chloride and DMF.pdf (54kB)
This file has been downloaded 338 times

EDITED:

Attachment: Alcohols to Alkyl Chlorides with TCCA and Triphenylphosphine.pdf (26kB)
This file has been downloaded 373 times

[Edited on 15-7-2018 by Chemi Pharma]

MJ101 - 14-7-2018 at 06:34

@Chemi Pharma: Thanks for the links. :)

I downloaded the first link and I couldn't see the gif image in the MS Word Viewer. I couldn't copy it from the document either.

Here it is, in case anybody else runs into that problem

https://chemistry.mdma.ch/hiveboard/picproxie_docs/000372508...

Chemi Pharma - 14-7-2018 at 07:53

@MJ101, posting again printed in .pdf. No more pictures problems, I guess:

Attachment: Alcohols to Alkyl Chlorides with TCCA and Triphenylphosphine.pdf (26kB)
This file has been downloaded 289 times

AJKOER - 15-7-2018 at 04:14

I would examine proposed commercial methods for the chlorination of, for example, CH4 involving combustion or heating with chlorine (explosion hazard) or the associated alcohol and hydrogen chloride. The idea would be to try to apply a methane chlorination process to the alkane hexadecane.

In general, these commercial paths have been put forward to reduce the demand for chlorine (a cost factor) and are scalable. See, for example, discussion at https://patents.google.com/patent/US5099084 .

A cited catalyst, depending on the method, appears to be copper chloride perhaps mixed with the likes of potassium chloride, ferric chloride, and/or lead chloride.

The outlined path is, however, not a standard lab procedure, but if larger quantities and cost are important considerations, my suggestion may prove to be of value.

[Edited on 15-7-2018 by AJKOER]

VSEPR_VOID - 15-7-2018 at 06:20

Quote: Originally posted by Chemi Pharma  
As already mentioned by me at another topic: http://www.sciencemadness.org/talk/viewthread.php?tid=80658&... , alkyl chlorides can be achieved from any kind of primary, secondary, terciary or benzylic alcohols, with TCCA and Triphenylphosphine. Archive attached below.

Other way, without the use of nasty and hard to get thionyl chloride or PCl3, PCl5 or POCl3 either, you can get the chloride from alcohol reacting the late with Cyanuric chloride and DMF in dichloromethane media, as attached below:

both methods will give you high yields, as you can read at the papers.







EDITED:



[Edited on 15-7-2018 by Chemi Pharma]


That seems out of reach for the amateur. So far I have been making isopropyl chloride by the continuous fractional distillation of zinc chloride, aqu. HCl, and the alcohol. This has had a slightly poor yield and takes a long time. I wonder if I could try and attempt the same reaction using TCCA. This might yield chloroform or proponic acid.