Sciencemadness Discussion Board

Chloroacetyl Chloride - Lachrymator, how much so?

RareEarth - 22-10-2015 at 16:43

Chloroacetyl Chloride has a alkyl chloride group near by a acyl chloride group. The acyl chloride being more reactive. I wanted to use this molecule as a building block for a macro-molecule, but am a bit hesitant because of the lachrymator properties.

There is a similar molecule, Chloromethyl Benzoyl Chloride, with the only difference being that it contains an aromatic ring. It's a solid, therefor easier to handle, but I fear it may have different reactivity profiles with the alkyl group being more reactive because of the ring, which won't do for me.

Anyone ever handle Chloroacetyl Chloride?

Ozone - 22-10-2015 at 17:02

Yes. It's not that bad. Nothing like chloromethyl anything (or benzyl chloride/bromide, for that matter). It handles like acetyl chloride. We used it on an open bench in 2nd year lab to make α-chloro-2,6-dimethylacetanilide from 2,6-dimethyl aniline en-route to lidocaine.

With good ventilation or a fume hood, no worries.

O3

[Edited on 23-10-2015 by Ozone]

RareEarth - 22-10-2015 at 18:09

I don't presently have a fume hood, but ventilation yes. I wasn't planning to heat it or anything, due to its reactivity. I just was wary of whether or not it was one of those things where you open the bottle and immediately start choking and being unable to see.

Dr.Bob - 22-10-2015 at 18:20

It is not too bad, but just make sure that you add it slowly to your reaction and be ready to cool if it a large scale. It is very water reactive, but as Ozone said, not as bad as benzyl bromides. I have also found chloroacetic acid to work better than I expected for many reactions, especially if you want to do an SN2 first and then react the acid next. The chloroacetyl chloride normally reacts first at the acid chloride, then does the SN2 second, if given the chance. Of course, the reactivity can be changed by altering the solvent, base, and the reagents being added. I remember TAing the lidocaine experiment in gradual school. A few students actually got good product, most got a mess. The key to using it is making accurate measurements of your reagents, as using almost exactly one equivalent of the first nucleophile and letting it react entirely to completion before adding the second one will give better results.

RareEarth - 22-10-2015 at 18:32

Luckily the product I am reacting it with is an insoluble support so I can't imagine much to go wrong. I was just going to add it to a solvent like toluene, stir for a little bit, and then filter it out.

Ozone - 22-10-2015 at 19:04

Gradual School. LOL. Many years later, I too got to oversee this. Honestly, we were more worried about the waste jugs. Despite all admonishment, spent nitration acid invariably made it into organic waste. Ugh. Also, occasionally, it went *boom* in waste storage. The chloroacetyl chloride was the last thing we were actually worried about.

[Edited on 23-10-2015 by Ozone]