Sciencemadness Discussion Board

Possible easy thionyl chloride synthesis

Opylation - 10-12-2019 at 19:48

Hey all,

One of the chemicals I’ve been wanting to make for a while now is thionyl chloride. I’ve been doing some research and the original way I was going to make it, using SCl2 + SO2 + Cl2 seems a little cumbersome. I have, however, seen a synthesis for thionyl chloride that uses phosgene. Now I know phosgene is a gas and gases can be difficult to control, but this got me thinking. Diphosgene is a liquid and triphosgene is a solid. Maybe phosgene can be replaced by one of these? Also diphosgene can be easily synth’ed using Cl2 + MeOOCH and daylight. Even better yet, SO2 and phosgene/ diphosgene are soluble in Chloroform. Could one possibly make a solution of SO2 (CHCl3) and add to diphosgene?

I am curious.
Let me know what you guys think!

Edit: it looks like diethyl ether might be a better solvent however I was unsure how SO2 or diphosgene would react with it

[Edited on 11-12-2019 by Opylation]

[Edited on 11-12-2019 by Opylation]

woelen - 11-12-2019 at 00:03

You want dead?
Phosgene is extremely dangerous. Only a very small amount is needed to screw up your lungs. Warning properties of the gas are mediocre at best. If you smell it, then you're most likely screwed already.

I myself have worked quite a lot with true nasties in my home experiments (e.g. PCl5, PCl3, Cl2, even HCN), but I never had the "courage" to work with COCl2. I have the chems to make this, but I never attempted to do this.

Diphosgene and triphosgene are a little less dangerous, because they are liquids, but their vapors also are very dangerous. Besides that, making diphosgene from methylformiate and Cl2 is not easy at all. Do not expect the reaction to be fast and complete. You have to deal with incomplete chlorination and side reactions.

Leave working with these to the pros, who have a well-equipped lab with adequate safety measures and who let people wear special phosgene-detection batches.

Some years ago, someone from this forum died after COCl2-exposure (IIRC the member had username myfanwy). He used to make several dangerous reagents, which went fine each time. This might have made him over-confident of his own capabilities. But, one day he went too far with making phosgene, and passed away after suffering from severe pulmonary edema. He was still in his teens and we lost a very dedicated, but sometimes somewhat reckless, member.

Pumukli - 11-12-2019 at 02:33

Use a bit more common sense!

If there was an easy, accessible route to thionyl-chloride then wouldn't it be already discovered? Why would the inorg. prep. books list those cumbersome routes that are listed instead of a less demanding one - if such one existed?
How probable that your proposed route is a radically new one and never thought of by other, more knowledgeable chemists?

I don't want to dwell into things like safety, hazards, etc. Woelen already pointed it out.

May I ask what was the most complicated preparation you successfully carried out?

Very basic things can go wrong and a seemingly easy synth could become very challenging at times. Thionyl chloride synths are easy only on paper.

draculic acid69 - 11-12-2019 at 03:09

Socl2 can be bought with some difficulty and made with sulfur compounds with some difficulty but it's not worth the risk of trying something as crazy as phosgene synthesis to yeild it.

Metacelsus - 11-12-2019 at 05:34

Yeah, phosgene is no joke. There was an extra special safety training required by my university when I needed to use it a few years ago. (And that was for a 20% solution in toluene. A gas cylinder of phosgene would be a whole different level of scary.)

Please don't kill yourself!

Opylation - 11-12-2019 at 10:57

Hey all,

I appreciate all of your concerns and I do just want to say that at this moment it is just theoretical. I just wanted to see what others thought of the idea. I am very aware of the dangers of phosgene which is why I didn’t want to handle the gas at all. Also, this wouldn’t be attempted anywhere else besides outside to avoid any accidental contact. I was thinking using diphosgene or triphosgene would be better as residence time in liquids is by quite a large margin better than gases. But then again, that’s why I posted on here first before carrying anything out.

Σldritch - 11-12-2019 at 12:24

A crazy (but less so) idea is to make it from Trichlorosulfonium Hexachlorostannate ( (SCl3)2SnCl6 ) and Sulfur Dioxide. I would imagine Sulfur Dioxide is too inert though.

SWIM - 12-12-2019 at 15:08

Doing it outside to be safe? Ypres was outside.

Phosgene was used as a war gas because it works well for killing people outside.
It's dense, it's insidious, it's also several other things I can't remember that make it more persistent than you'd think.

I would be much happier using phosgene than mustard gas, but that's a pretty low bar.
(Either can kill you, but the phosgene is less painful and leaves a prettier corpse.)

I'm not even crazy about using chlorine in any quantity, but with that stuff you KNOW when you're exposed.
Your more sophisticated war gasses are much sneakier.

I read somewhere that sub-lethal phosgene levels make cigarettes taste bad (described as metallic), but I'm not eager to find out for myself.

If you do screw around with this stuff bear in mind that activated charcoal filters will adsorb it, but they also release it back into the environment slowly.
This means an activated charcoal only mask won't keep you alive through extended exposure.




draculic acid69 - 12-12-2019 at 19:48

You will need a full spaceman suit type thing to be even near safe using phosgene.
Maybe a full body scuba wetsuit with an oxygen tank far far away from ppl and civilization.outside doesn't equal safe.

Cou - 12-12-2019 at 20:06

I think chemsavers sells to amateurs and residential addresses, not sure. Maybe they ship benign chemicals to amateurs, but are more picky about nasty chemicals?

https://chemsavers.com/t/thionyl-chloride-99-100-ml/

Dan Vizine - 18-12-2019 at 12:32

Diphosgene and Triphosgene are simple to use, relatively safe direct replacements for phosgene in most reactions. We used it routinely in mediocre fume hoods with simple carbon respirators to augment the protection. None of us ever had the slightest issue with it.

The awe in which phosgene is held is somewhat disrespectful to bromine. Bromine is easily in the same neighborhood of toxicity and few of us think twice about using it. The use of di- and triphosgene makes potential exposures quite a tolerably low risk for any chemist of moderate or better skills.

From CDC:
For bromine

It has been reported that 1.7 to 3.5 ppm produces severe choking, 4.5 to 9 ppm is extremely dangerous, and 30 ppm would prove fatal in a short time.
Current OSHA PEL: 0.1 ppm (0.7 mg/m3) TWA

For phosgene

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Jacobs that 1 part in 200,000 (5 ppm) is probably lethal for exposures of 30 minutes. A level of 30 ppm is estimated to prove fatal in 17 minutes.
Current OSHA PEL: 0.1 ppm (0.4 mg/m3) TWA

In contrast to what woelen had suggested, merely detecting the odor of phosgene is of no big significance. I've smelled it numerous times. It smells just like everybody who's smelled it in the past has said it does, like moldy hay.



[Edited on 12/18/2019 by Dan Vizine]

Amos - 18-12-2019 at 13:09

Thanks Dan, always nice to see someone experienced and with their wits about them ready to scare the bogeyman away. Give it a few more decades and people will tell you of all the horrific threats nitrogen dioxide poses and how it must never, ever be synthesized. Anything outside the realm of the more serious organometallics can probably be handled in a well-ventilated area by an experienced and level-headed amateur.

DraconicAcid - 18-12-2019 at 13:38

Quote: Originally posted by Dan Vizine  
In contrast to what woelen had suggested, merely detecting the odor of phosgene is of no big significance. I've smelled it numerous times. It smells just like everybody who's smelled it in the past has said it does, like moldy hay.


I've often read in books that it smells like fresh-cut hay. The only time I've smelled it, it was like the rancid bottom of an old lawn mower, and it took me surprisingly long to put connect the smell with the description.

Dan Vizine - 18-12-2019 at 13:51

Amos,
So true. I've made liquid hydrogen cyanide (170 g) and bromine (1 kg/run) in my basement with no fume hood. I have no ill effects to show for it.

Joints are all ground glass, all joints are well greased, the joints are secured with Keck clamps, all glassware is suitable supported and a vent tube runs from the apparatus to the great outdoors. I wear a respirator, work behind a Plexiglas shield as needed and I've been doing it for a long, long time. I think my first job taught me a lot, if you didn't look out for your own safety there, nobody did it for you.

Draconic acid, it's unique, isn't it? The smell always reminds me of fall the same way that the smell of HCN reminds me of Thanksgiving.

[Edited on 12/18/2019 by Dan Vizine]

SWIM - 18-12-2019 at 16:38

Quote: Originally posted by Dan Vizine  

The smell always reminds me of fall the same way that the smell of HCN reminds me of Thanksgiving.

[Edited on 12/18/2019 by Dan Vizine]


Wow, that is a great quote.

Fair warning: If I ever write anything with an organic chemist character, I'm probably gonna steal it.

[Edited on 19-12-2019 by SWIM]

Oh, BTW: the Chemsavers link says commercial addresses only.


I don't know if the commercial address also has to be somewhere that might actually have a reason to buy stuff like that.

Like getting it delivered to the fish and chips shop you own, or your friend's office (He's a chartered accountant, don't you know), might not work.



[Edited on 19-12-2019 by SWIM]

Dan Vizine - 18-12-2019 at 19:19

This is pretty much just an academic discussion anyway. The cost of these phosgene precursors is quite high and their availability is such that anybody able to buy one of them could just as easily buy the thionyl chloride.

DraconicAcid - 18-12-2019 at 19:45

Quote: Originally posted by Dan Vizine  
Draconic acid, it's unique, isn't it? The smell always reminds me of fall the same way that the smell of HCN reminds me of Thanksgiving.


Unique among chemicals, sure. It doesn't remind me of fall, though- I never did much mowing of lawns after high school, and that was always over the summer (I grew up in the north, beyond The Wall, where grass simply stopped growing two weeks into September).

Mush - 13-1-2020 at 12:29

Quote: Originally posted by Opylation  
Hey all,

One of the chemicals I’ve been wanting to make for a while now is thionyl chloride. I’ve been doing some research and the original way I was going to make it, using SCl2 + SO2 + Cl2 seems a little cumbersome. I have, however, seen a synthesis for thionyl chloride that uses phosgene. Now I know phosgene is a gas and gases can be difficult to control, but this got me thinking. Diphosgene is a liquid and triphosgene is a solid. Maybe phosgene can be replaced by one of these? Also diphosgene can be easily synth’ed using Cl2 + MeOOCH and daylight. Even better yet, SO2 and phosgene/ diphosgene are soluble in Chloroform. Could one possibly make a solution of SO2 (CHCl3) and add to diphosgene?

I am curious.
Let me know what you guys think!

Edit: it looks like diethyl ether might be a better solvent however I was unsure how SO2 or diphosgene would react with it

[Edited on 11-12-2019 by Opylation]

[Edited on 11-12-2019 by Opylation]


Playing with war gases at home ?:o Forget about it.

If they managed to f***k up and kill their employee, you will def. kill yourself and others.

Fatal Exposure: Tragedy at DuPont
https://www.youtube.com/watch?v=ISNGimMXL7M

XeonTheMGPony - 13-1-2020 at 16:13

Quote: Originally posted by Mush  


If they managed to f***k up and kill their employee, you will def. kill yourself and others.



and yet people kill them self's every day with water, I am afraid to tell you, life ultimately will kill you too!

If you think you can do it, go for it, your body your right to do what ever you please with it, just do your due research and warn those around who may come to investigate should you keel over

Mush - 13-1-2020 at 16:47

Quote: Originally posted by XeonTheMGPony  
Quote: Originally posted by Mush  


If they managed to f***k up and kill their employee, you will def. kill yourself and others.



and yet people kill them self's every day with water, I am afraid to tell you, life ultimately will kill you too!

If you think you can do it, go for it, your body your right to do what ever you please with it, just do your due research and warn those around who may come to investigate should you keel over


What is this mumbo-jumbo? I don't get it.

Did you watch the video, btw? I don't think so.

Please elaborate . I would like to know more about deaths caused by water vapour in 50 ppm concentration.

XeonTheMGPony - 13-1-2020 at 18:21

Quote: Originally posted by Mush  
Quote: Originally posted by XeonTheMGPony  
Quote: Originally posted by Mush  


If they managed to f***k up and kill their employee, you will def. kill yourself and others.



and yet people kill them self's every day with water, I am afraid to tell you, life ultimately will kill you too!

If you think you can do it, go for it, your body your right to do what ever you please with it, just do your due research and warn those around who may come to investigate should you keel over


What is this mumbo-jumbo? I don't get it.

Did you watch the video, btw? I don't think so.

Please elaborate . I would like to know more about deaths caused by water vapour in 50 ppm concentration.


Well as I thought, you don't think well!

I seen that video year ago and a great many more, I have seen worse at real time, and I seen people die from a simple every day trivial mistake.

For some reason I feel no need to cower in a closet and cry.

If the user uses their mind, researches and does things carefully they are no more in danger then any other substance in every day life.

They just need t be aware the dangers are very real and take proper percuations.

[Edited on 14-1-2020 by XeonTheMGPony]

chemplayer... - 18-1-2020 at 17:50

Unless you've got a pro-lab set-up, probably an approach to steer clear of:

http://www.sciencemadness.org/talk/viewthread.php?tid=54656

morganbw - 19-1-2020 at 10:43

Quote: Originally posted by chemplayer...  
Unless you've got a pro-lab set-up, probably an approach to steer clear of:

http://www.sciencemadness.org/talk/viewthread.php?tid=54656


Yea, for most of us. I doubt that I will be dealing with it but there is literature that does go over some things. One thing for sure, is do not piss in the wind.

Do nothing unless it is researched and your confidence is high.

XeonTheMGPony - 19-1-2020 at 11:50

Quote: Originally posted by morganbw  
Quote: Originally posted by chemplayer...  
Unless you've got a pro-lab set-up, probably an approach to steer clear of:

http://www.sciencemadness.org/talk/viewthread.php?tid=54656


Yea, for most of us. I doubt that I will be dealing with it but there is literature that does go over some things. One thing for sure, is do not piss in the wind.

Do nothing unless it is researched and your confidence is high.


^^^^^^^^^^^^^ That is the proper answer to any dangerous procedure.