MKSStal
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Bromine from bromoform
I have seen a shop in which I can buy pure bromoform in quite a good price. Calculating per mole of bromine atoms its about 3,7 - 5,5 times cheaper
than potassium bromide. Because of that I thought about isolating that bromine out of bromoform. Of course the best form would be into bromide ions.
Could you propose some method for doing it?
Classic hydrolysis using NaOH water solution won't do forming dibromocarbene at best, am I right?
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Boffis
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@MK S Stal
I find it difficult to believe that bromoform is cheaper that a simple bromide salt such as sodium bromide. In the UK I can buy more than 5kg of
sodium bromide for the Price of 100g (35ml) of bromoform. I guess it depends on your ultimate target but making potassium bromide from bromoform is
like like making scrap metal out of a Rolls Royce!
However, if you have money to burn here are a few ideas. I have made diiodomethane from iodoform by reduction with sodium borohydride to give
diiodomethane and sodium iodide +boric acid in the aqueous phase, most published procedures us sodium arsenite but this appears to be because this
reducing agent stops after removing just one halogen and you want to remove them all, the aresenate in the residue would also complicate the work up.
It may be possible to do this with bromoform and by using an excess of sodium borohydride though the volatility of of the monobromomethane (a gas; a
toxic gas too) may make this difficult. This process, however, is like making scrap metal out of a Rolls Royce using a Tomahawk cruise missile.
It may be possible via straight hydrolysis with alkali to formate and bromide. If you're worried about carbenes throw in some phenol and get some
salicylaldehyde as a by-product. 
If bromoform is so cheap where you are.... hell .... just get on with it and experiment! and don't forget to tell us how you get on.
By the way where are you? Roughly.
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MKSStal
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I think it's all about this specific shop. They have very unreasonable prices in few cases. For example for the price of 50g pure potassium iodide you
can buy 3 ampules containing 3,567g of potassium iodate and 35g of potassium iodide for making standard solution of iodine. Any logic?
It's an online shop, so after seeing this offer i started thinking about using this as a source of bromine. Of course cheap reagents as NaOH should be
used to make sence in it. You think, that simply mixing it with sodium hydroxide aq. solution (on magnetic stirrer) could do the job? I concluded that
phenol should be used in stechiometric amount, am I right? Could benzene be used instead of phenol or it would couse problems due to lesser reactivity
or insolubility in aq. NaOH? Just asking about some ideas as I'm considering buying it online.
I'm from Poland. In our greatest lab company KBr is of course cheaper than bromoform however not in such great ratio as in UK. KBr is more frequently
used and sold in Poland than the sodium salt.
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MKSStal
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Ok, now I know, that benzene couldn't be used, because it's Reimer-Tiemann reaction and it needs phenol.
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MKSStal
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So, I already bought 250 ml of pure (according to etiquette) bromoform for 22 złote (PLN) = 5,65 USD 
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mayko
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You might be interested in my observation of the decomposition of unrecrystallized iodoform, apparently creating elemental iodine (starting here)
al-khemie is not a terrorist organization
"Chemicals, chemicals... I need chemicals!" - George Hayduke
"Wubbalubba dub-dub!" - Rick Sanchez
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