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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: tdod on November 23, 2013, 01:41:02 PM

Title: Why such low yield of diphenylacetylene?
Post by: tdod on November 23, 2013, 01:41:02 PM

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My yield was low (28%) and I am wondering if there is some feature of the chemistry that makes this low yield. The only work up was vacuum filtration and an ethanol wash, so unless a side-product was produced then i can't figure out what happened to the yield. Reaction progress wasn't monitored bny TLC but it was heated at 160˚C for ten minutes.

Thanks!

Title: Re: Why such low yield of diphenylacetylene?
Post by: discodermolide on November 23, 2013, 02:29:46 PM

If your yield was only 28% what is the rest of the material?

Title: Re: Why such low yield of diphenylacetylene?
Post by: spirochete on November 23, 2013, 05:21:34 PM

Maybe the high temperatures cause decomposition of the starting material? Maybe try a lower temperature and a stronger base?

Or you're getting significant amounts of substitution product for some reason? Lilke disco said you need to give us more info.

Title: Re: Why such low yield of diphenylacetylene?
Post by: zsinger on November 23, 2013, 07:01:06 PM

The second elimination would probably need a stronger base, or higher temperatures.  But, as Spiro said, we need all rxn. conditions to better help you :).