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Topic: Synthesis of p-cyanobenzoic acid  (Read 4505 times)

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Offline syunchow

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Synthesis of p-cyanobenzoic acid
« on: June 28, 2011, 12:20:19 AM »
Hi,

I'm having problem with the synthesis of p-cyanobenzoic acid. I started with p-tolunitrile, dissolved in sulfuric acid and added potassium dichromate with temperature maintained at 0 degree,  and then continue stirring at r.t for 48 h. The methyl group was oxidized to carboxylic acid group successfully but unfortunately the nitrile group has also been hydrolyzed into carboxylic acid. Is there a way to prevent this?

Offline OC pro

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Re: Synthesis of p-cyanobenzoic acid
« Reply #1 on: June 28, 2011, 02:03:04 AM »
According to this reference with Ruthenium trichloride: J. Org. Chem. 1986, p.2880.

Offline Åke

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Re: Synthesis of p-cyanobenzoic acid
« Reply #2 on: June 28, 2011, 10:57:33 AM »
Try: Levine, M.; Sedlecky, R. Preparation of p- and m-Aminomethylcyclohexylcarboxylic Acid. J. Org. Chem. 1959, 24, 115. http://pubs.acs.org/doi/abs/10.1021/jo01083a608

Offline syunchow

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Re: Synthesis of p-cyanobenzoic acid
« Reply #3 on: July 05, 2011, 09:13:13 PM »
Yayyy! I have solved this issues. Using the same condition, I kept the sulfuric solution at 0 degree, and instead of long reaction time, I shorted it to 5h - got my compound without nitrile hydrolysis  ;D

Offline Vidya

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Re: Synthesis of p-cyanobenzoic acid
« Reply #4 on: July 05, 2011, 11:36:58 PM »
That's really great

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