DEA To Update Watched Chemicals List To Include Sodium Borohydride

[uj74eer]

I've been debating turning my pcl5 into thionyl chloride to avoid producing pocl3 when I need things chlorinated. The only reason I have to keep pcl5 is for vilsmeier which I haven't done in months

Personally, I would recommend keeping it as PCl₅ and only synthesizing SOCl₂ when you know you'll need it sometime in the next reasonable amount of time. It's a bit of a pain to purify the SOCl₂ POCl₃ mixture to perfection, but having SOCl₂ handy when the time comes to use it is really nice. It is subject to photolysis and slowly degrades and is all around nasty stuff so I, too, prefer keeping PCl₅ in storage than thionyl chloride.

The synthesis is very visually appealing though. Colorless gas + colorless solid -> colorless liquid. Very cool to see.

[atara]

Not sure I understand the fuss about nabh4 being watched, the time spent figuring out how to get or make nabh4 could be better spent figuring out how to reduce without it

There was this chinese patent, the NaBH4 was made from Mg metal and some borax sodium carbonate, water in a ball mill: https://www.sciencemadness.org/whisper/viewthread.php?tid=158235

One would have to make a tightly sealed ball mill, that could bee filled with argon though and afterwards wind a way to recrystallise the NaBH4 without hydrolysis. Quite a bit of a hassle and specialised equipment.

Honestly kind of overcomplicated when you can just buy the best precursor to borohydride and react it with alkali hydroxides

[big mac]

Honestly kind of overcomplicated when you can just buy the best precursor to borohydride and react it with alkali hydroxides

What's the precursor?

[Loki]

Honestly kind of overcomplicated when you can just buy the best precursor to borohydride and react it with alkali hydroxides

What's the precursor?

I'd be interested to know as well, because I was under the impression the easiest for the amateur would be sodium hydride and trimethyl borate. I was thinking borane and sodium hydroxide, but I am fairly sure that would produce sodium metal.

[Osmiridium]

Honestly kind of overcomplicated when you can just buy the best precursor to borohydride and react it with alkali hydroxides

What's the precursor?

[Mrbovinejony]

And why isn't this method used or talked about more? I see no cheap magnesium diboride or easy way to make it

[Rawhide Kobayashi]

I read that the yields are very low like 10%, and isolating the pure borohydride without decomposition would be tricky.

[Osmiridium]

There's no guarantee that this is what atara was talking about, but it was all One could find.

[atara]

Yeah I was talking about the MgB2 method. The yield is about 10% of the boron but considering the electronics that's around 40% of theory. So not awful. The nice thing about MgB2 is that it's basically completely stable and easy to store which helps make up for the huge excess.

I suspect you could get a better yield if you used a mixture of MgB2 and metallic Mg. That would improve the theoretical yield substantially.

The balanced equations:

2 MgB2 + 4 NaOH >> NaBH4 + 2 MgO + NaBO2 + 2B

2 MgB2 + 8 NaOH + Mg >> 2 NaBH4 + 4 MgO + 2 NaBO2

Using KOH instead might also increase the yield but the product KBH4 is less reactive and less soluble. No idea if it would still work for the CuCl2 bit.

[Kasey Jones]

You're not American are you?

They'll fuck whoever they can as much as they can.  It's a fucking racket: cops, lawyers, judges and prison industrial complex.  Fucking sucks

[Trianion]

I feel stupid in this cat and mouse but do theylimit methylbenzene?

[D34d37h3r08]

Does anyone know if there would be any reprecussions for some little no body selling a couple kg worth NaBH4 on ebay?

[Sawdust and Honey]

Probably no, but it's not the wisest thing to post about it here.