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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Plumbum on May 12, 2015, 12:45:43 PM

Title: P-Chlorobenzoic acid
Post by: Plumbum on May 12, 2015, 12:45:43 PM

Hi

Can anyone tell me Now what side product could there be when synthesizing 4-Chlorobenzoic acid. I used 4-Aminobenzoic acid
It was a sand ever reaction.

Title: Re: P-Chlorobenzoic acid
Post by: sjb on May 12, 2015, 04:53:21 PM

Quote from: Plumbum on May 12, 2015, 12:45:43 PM

Hi

Can anyone tell me Now what side product could there be when synthesizing 4-Chlorobenzoic acid. I used 4-Aminobenzoic acid
It was a sand ever reaction.

What are the intermediates? How did you carry out the reaction?

Title: Re: P-Chlorobenzoic acid
Post by: Plumbum on May 12, 2015, 06:06:18 PM

I first synthesized the diazonium compound by dissolving 4-aminobenzoc acid in water and hydrochloric acid.

Then I synthesized copper(1) chloride.

Then I mixed my dissolutions( Sandmeyer).

Title: Re: P-Chlorobenzoic acid
Post by: pgk on May 12, 2015, 06:29:02 PM

Did you exceed the reaction temeperature above 5oC (mesured by a thermometer, in real time)?

Title: Re: P-Chlorobenzoic acid
Post by: Plumbum on May 13, 2015, 06:06:45 AM

I dont think so IT was supposed to be between 0 and 5 degrees

Title: Re: P-Chlorobenzoic acid
Post by: pgk on May 13, 2015, 01:25:07 PM

Then, a possible side product might be p-hydroxybenzoic acid by partial hydrolysis of the diazonium salt.
Also, note that above 5oC, the diazonium salt decomposes to benzoic acid and gaseous nitrogen that might be explosive. By the way, did you notice any bubbles formation in the reaction medium? 

Title: Re: P-Chlorobenzoic acid
Post by: Plumbum on May 14, 2015, 12:16:37 PM

Thank you very much :)

What side products would you expect for the synthesis of antrillic acid ?

Title: Re: P-Chlorobenzoic acid
Post by: pgk on May 14, 2015, 01:05:12 PM

Do you mean anthranilic acid?

Title: Re: P-Chlorobenzoic acid
Post by: Plumbum on May 14, 2015, 01:39:01 PM

Yes i do, sorry!

Title: Re: P-Chlorobenzoic acid
Post by: pgk on May 14, 2015, 01:52:52 PM

What is the structural difference between anthranillic acid and PABA?
Then, the answer is easy.

Title: Re: P-Chlorobenzoic acid
Post by: Plumbum on May 14, 2015, 02:07:46 PM

Well the NH2 group is ortho in anthranillic acid and para in PABA

Title: Re: P-Chlorobenzoic acid
Post by: pgk on May 14, 2015, 02:18:19 PM

So, what is the most possible side product of the synthesis of one of them?

Title: Re: P-Chlorobenzoic acid
Post by: Plumbum on May 14, 2015, 02:58:58 PM

I don't know, the meta derivative?