kclo4
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How to make N, N'-diphenylurea
Well.. i searched and i can't really seem to figure out how to make it but it seems that it might be rather easy?
Mixing Urea and Phenol would work if you could get them to condense, or dehydrate, right?
so i would think sulfuric acid could work by combining the two and taking the water out of the reaction?
or am i just starting with the wrong chemicals?
Oh yes and i want to make this chemical because its a plant growth hormone, if anybody was wondering because i don't think this has any other uses..
does it?
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12AX7
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I would hazard a guess that C6H5X (X = Br or I) would be more suitable, condensing with loss of HX. I would also hazard a guess that steric
hinderance would keep more than one C6H5 plopping down on the N's, but there are potentially three positions to occupy, under acidic conditions...
I would be afraid that urea and phenol would tend to condense in all sorts of positions. Yeah, that's formaldahyde and phenol or urea that turns to
resin, not urea and phenol but still.
Tim
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kclo4
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How could you shift it so more reacted how you wanted them too, also how hard would it be to separate them?
i bet they're properties would a lot different from each other
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garage chemist
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None of the ideas so far will work!
Chloro- and bromobenzene are very unreactive and will not react with ammonia and amines even at reflux. It takes gas-phase reaction with high
temperatures and catalyst to get those to react, or an autoclave. At those conditions the urea will be completely destroyed (hydrolysed).
Phenol needs similar conditions to react at the hydroxyl, and will certainly not react with urea at normal conditions!
Halobenzenes, unless activated by nitro groups, are no alkylating agents!
Sym-diphenylurea (carbanilide) could for example be made from aniline and phosgene.
Since phosgene is not easy to make and handle, another active carbonyl compound will have to be used.
Urea and aniline might undergo transamidation to yield your diphenylurea and ammonia. The ammonia escaping as gas will drive the reaction formward.
Actually, this is the method for making carbanilide as I read up in Ullmann.
Quote:
N,N' -Diphenylurea[102-07-8] , carbanilide, C6H5HNCONHC6H5 , mp 238 °C, can be produced in high yields by heating 2 mol of aniline with 1 mol of urea
in glacial acetic acid.
The following reference is being given:
A. Sonn, Ber. Dtsch. Chem. Ges. 47 (1914) 2440
This journal is freely accessible at gallica. Go find that reference.
I can help you with the german if necessary.
[Edited on 16-8-2007 by garage chemist]
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The_Davster
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Triphosgene can be used instead of phosgene, and is considered the sane alternative in these types of reactions.
However acquisition is likely even harder.
Triphosgene is:
Cl3OCOOCCl3
The first aniline will substitute quick, the second usually takes refluxing from what I have read.
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garage chemist
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Usage of triphosgene requires a base to bind the HCl produced, otherwise the aniline will be converted to the hydrochloride.
But since urea does the job instead of triphosgene, those considerations are unnecessary.
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