metalayer
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2,3 dichlorobenzoyl chloride
I purchased some 2,3 dichlorobenzoyl chloride. This compound has an acyl chloride group but what I have doesn't react with water. The mp is correct
however. Is it safe to say I have been ripped off?
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NitreRat
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Maybe it just reacts with water slowly like acetic anhydride. The electron withdrawing chloro groups on the benzene ring could be slightly
deactivating the acyl chloride. Does it react with bases or nucleophiles? A good test for acyl chlorides is the reaction with silver nitrate which
would precipitate white silver chloride.
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metalayer
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It reacted instantly with triethylamine, producing a yellow/white solid. That seems like the expected reaction between an amine and acyl chloride?
[Edited on 14-7-2015 by metalayer]
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NitreRat
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Well, triethylamine is a base so in aqueous conditions you would expect it to react with an acyl chloride, precipitating triethylammonium chloride,
but the reaction shouldn't occur without water. Would it be possible to retry your test in anhydrous conditions? If it doesn't react with anhydrous
triethylamine I would strongly suspect that you do indeed have 2,3 dichlorobenzoyl chloride.
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Dr.Bob
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Try reacting it with ammonia or another good nucleophile. Those benzoyl chlorides are not real reactive so they will hydrolyze slowly in water.
2-chlorobenzoyl I just used, and it does not do a thing immediately, but slowly hydrolyzes over hours. That is how I work up the reaction to remove
the excess acid chloride, then extract with aqueous base to remove the remaining acid. The amide reactions take overnight most times.
Bob
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Nicodem
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Thread Moved
14-7-2015 at 09:12 |
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