Sciencemadness Discussion Board

Alkyl iodides from argox rxn in situ, temp question

Cabalaba - 15-6-2016 at 06:19

As you saw in my first post, contaminated HBr with Br2, it was a mistake. Since I want alkyl halides, I should have done smaller batches each with the corresponding alcohol in each. We all have brain farts, I guess I was preparing for halogenating alcohols I was planning on running.

In this post I specifically want to know how to deal with alkylating an iodine atom, all in one pot.

The question I have because I don't want HI lying around (due to its legal status) and even though this is questionable, I'm wondering when do I add the alcohol (say 2-propanol), Argox got some HI under or around 150℃ then again at 400℃.

To my understanding, an alcohol or alkylated halide at 400℃ is a problem.

It sounds like a nice relatively one sided protocol, I will be using it for other chlorine and bromine halogenations but the high temps here worry me.

Would using more H3PO4 be a way around hitting 400℃?

In this case, if I choose the one pot method, any advice or precautions. Otherwise, I think I'm stuff doing the two step method and immediately halogenationing the alcohol.

I've done many alkylating halogenations, but avoided anything with HI.

Also I have read quite a few reports on this site, some parents, but may have missed something.

Orenousername - 15-6-2016 at 11:03

You don't need HI if all you want to do is prepare alkyl iodides from alcohols.

Chemplayer has a few videos on this and if you can't obtain phosphorous then aluminum seems to work as well. This also apparently works better for methyl iodide than ethyl iodide.

I believe PI3 or AlI3 is formed in-situ which then reacts with the alcohol to form the corresponding alkyl halide, but I'm not sure.

[Edited on 6-15-2016 by Orenousername]

[Edited on 6-15-2016 by Orenousername]

Cabalaba - 15-6-2016 at 12:14

Thanks, I don't have P but I do have Al. Wonder how I missed that video