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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: makfc on April 21, 2006, 10:10:49 AM

Title: Removing Iodine & Acetyl chloride
Post by: makfc on April 21, 2006, 10:10:49 AM
I done an acetylation reaction of 3-hydroxy benzldehyde very well using acetyl chloride as acetylating agent and iodine was used as a powerful catalyst in this solvent-free reaction.

But after the reaction completion, in work-up, what should I do to remove both these reagents ? I read that Sodium thiosulfate can be used for iodine but also read that it may also react with my aldehyde.

Pls suggest something....



makfc

Title: Re: Removing Iodine & Acetyl chloride
Post by: faust on April 21, 2006, 02:59:47 PM
a simple wash with alkaline water should be ok!
Title: Re: Removing Iodine & Acetyl chloride
Post by: makfc on April 22, 2006, 12:17:30 AM
faust !

It (NaHCO3) may work for acetyl chloride but not for iodine.

What for Iodine ?

Title: Re: Removing Iodine & Acetyl chloride
Post by: Yggdrasil on April 22, 2006, 12:24:57 AM
Sodium bisulfite can be used to remove iodine, but I don't know whether it will react with an aldehyde.
Title: Re: Removing Iodine & Acetyl chloride
Post by: Borek on April 22, 2006, 05:34:17 AM
I2 + 2S2O32- -> 2I- + S4O62-

No idea about aldehyde.
Title: Re: Removing Iodine & Acetyl chloride
Post by: Alberto_Kravina on April 22, 2006, 06:02:42 AM
Quote from: Yggdrasil on April 22, 2006, 12:24:57 AM
Sodium bisulfite can be used to remove iodine, but I don't know whether it will react with an aldehyde.
Sodium bisulfite reacts with aldehydes...it forms a white ppt. (so-called "bisulfite addition compounds")

R-CHO + NaHSO3 -----> R-CH-SO3-Na+
                                            |
                                            OH
Title: Re: Removing Iodine & Acetyl chloride
Post by: makfc on April 22, 2006, 11:49:06 PM
Oh friends !  :-[



So still I can't find the solution for this ?   :'(



Title: Re: Removing Iodine & Acetyl chloride
Post by: mir on April 23, 2006, 06:17:02 AM
Quote from: makfc on April 22, 2006, 11:49:06 PM
o still I can't find the solution for this ?   :'(

A brainstorm is in the best position now to solve the problem :-)
You should break the problem into small pieces and solve them one by one.

Addition of water will surely react with the acetyl chloride and form the acid.
It will probably make the hydrationproduct of the aldehyde to. Perhaps making it more watersoluble?


Title: Removing Iodine
Post by: makfc on April 25, 2006, 09:47:08 AM
Acetyl chloride is removed !  ;D

But what about Iodine ?

Still I'm looking something for this....  ???
Title: Re: Removing Iodine & Acetyl chloride
Post by: HP on April 25, 2006, 02:46:05 PM
I am thinking for purification your product from iodine using flash chromatography with starch as sorbent. Starch(amilose or amilopektine i cant remember) form blue complex compound with elemental iodine...Is your organic product soluble in ethanol?
Success!
Title: Re: Removing Iodine & Acetyl chloride
Post by: technologist on May 03, 2006, 03:40:18 AM
I dont know, as a wild thought, Will any LLE solvent work.
I mean where partition coeff for your aldehyde & iodine are diff.

See, every research has some commercial part attached to it.
So we have to see practical & economical solutions.

I am not aware of any such solvent right now, as I am not a chemist,
but getting it reacted with any compund such as sodium thio, carbonate, etc
doesn't have any commercial sense.

Thats why still lot of research is going on for Acetylation of Aromatics.
I know one process where solid catalyst is used which is re-usable without any
significant loss of reactivity, BUT yet to be tested.