Sciencemadness Discussion Board

Dumb Question

Jackson - 3-4-2019 at 09:14

Would the reaction of dry Na3PO4 with chlorine form POCl3 and NaOCl or NaCl and O2 if a large excess of chlorine was used? Would this be possible with strong uv lighting to generate free radicals of chlorine?

Metacelsus - 3-4-2019 at 09:50

I don't think there would be much of a reaction. Na3PO4 can't really be oxidized, and also it's a solid whereas Cl2 is a gas. There might be a small amount of reactivity at the surface but I don't think it's likely to form POCl3 in anything but trace amounts.

CharlieA - 3-4-2019 at 15:54

Why do you think that it will? (I have no idea what the answer is). Do you have a reference to what you want to do? Have you tried it? Are you hypothesizing from a theoretical basis (if so, I would like to know what it is)? Please don't take this as a snarky comment. I just wonder why you are proposing this particular reaction. Charlie:)

Jackson - 3-4-2019 at 16:56

i originally wrote it as using phosphoric acid but it generated water so i thought this was maybe a better route. i think the best route is probably from phosphorus chlorine and oxygen instead of the acid, but it would be pretty cool if it worked.

P.S. this is not based off anything. it probably should be in detritus

[Edited on 4/4/2019 by Jackson]

Sigmatropic - 4-4-2019 at 01:58

Generally speaking there are two types of chlorination.

1) electrophilic chlorination typically using some form of Cl+ in the form of reagents such as Cl2, HOCl, N-Chlorosuccinimide (NCS) or trichlorocyanuric acid (TCCA)

and 2) nucleophilic chlorination typically introducing Cl as the anion (after something has been activated to become a better leaving group). Typical reagents include nasties such as thionyl chloride, phosphorous oxychloride, phosphorous pentachloride, oxalyl chloride or (di, tri) phosgene but also chloride salts (in which case there is almost always already a leaving group installed) and lastly plain HCl (in which case there is a group activated by acid such as an epoxide, but also sometimes alcohols).

Radical chlorination would a third type but I think that is beyond the scope of this thread.

You've mixed up what kind of a reagent Cl2 is. It cannot replace OH for Cl, especially not on phosphoric acid.

Jackson - 4-4-2019 at 09:28

okay, thank you for the response.

CharlieA - 4-4-2019 at 15:56

This link references several ways to make POCl3:

Jackson - 4-4-2019 at 20:53

The main reason i want this POCl3 is to make trimethylphosphate for methylations. Could trimethylborate be used as a methylation agent? That would be way easier to make (just boric acid and methanol right?).

Rhodanide - 10-4-2019 at 13:37

Quote: Originally posted by Jackson  
(just boric acid and methanol right?).

Close, but not quite. You need concentrated H2SO4 as a catalyst, and then to reflux the mixture.

Jackson - 10-4-2019 at 23:24

could i use a mixture of methanol and H2SO4 as well as borax to methylated things, or would i have to separated the TMB from the solution?