Quenching Phosphorus Oxychloride

A comment on my post on phosphorus oxychoride (which I still get hits on even now) from Andy Nation asked if there was any Org Syn prep or other respected documentation on the work-up or quench of this reagent.

The first source I thought of was the MSDS but it doesn’t really talk about quenching, just the hazards. And it is so vague that it is hardly useful for this point.

Secondly, I thought of Bretherick’s Handbook of Reactive Chemical Hazards.

Then I did a quick search and turned up a paper in Organic Process & Development which might tell you more than you want to know.

Any others out there?

This entry was posted in safety.

5 comments on “Quenching Phosphorus Oxychloride

  1. Ben says:

    Why wouldn’t you just treat it like and organolithium, slowly add alcohol until the reaction clearly stops, or just add water ( SLOWLY). while the reaction is different, the principle is the same. make the compound go to a non reactive form.

  2. David Perrey says:

    The tricky thing with POCl3 is that it is unreactive at cool temperatures, and very reactive at room temp, so when you add it to the chilled water slowly (being careful) none of it reacts, then it warms up and all reacts at once, usually involving coating the ceiling of your fume hood.

    Andy wasn’t asking how to do it (that is in my original post, which I just added a link to above), but for an “official procedure”, as quoting a blog post is about as good as saying “this guy in the cafeteria told me to…”

  3. milkshake says:

    I woud not recommend alcohol quench – some phosphoester-halides are horribly toxic (i.e. diisopropyl fluorophosphate) neuro-paralytic agents. And methyl phosphates are alkylating agents.

    You can either use quench with aqueous potassium hydroxide (with some ice if you want) or opt for water-aceton mixture (to prevent phase separation). DMF excess works quite well too (You get a second exotherm when you quench the formed Vilsmeyer solution with water)

  4. Mark says:

    I’m looking for a coating that can protect against POCl3. I was thinking alumina or yttria, Al2O3 or Y2O3. Any other suggestions – boron carbide?

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