This is an orgo. theory question:

If I have a benzene ring with NH2 attached and want to replace this with COOH:

 _           _
/ \_NH2 --> / \_COOH
\_/         \_/

I believe that the text book way to do this is to convert the molecule to a disulfide salt with NaNO2 and HCl, then use Cupric Cyanide / Potassium CN to change it into a benzen ring with a CN on it.  Then it can be reacted in an acidic aqueous solution to get the desired molecule.

First off, is this correct?  Secondly, is there another route that can be used? 

No, I am not a college orgo student, that needs help on his homework.  I am an ignorant man trying to teach myself some chemistry.

1. NaNO2/H(+) ----> diazonium compound
2. React with CuCN ----> benzonitrile
3. hydrolyse to produce the acid

But my question was if that was the only path to the final compound?

http://www.chem.leeds.ac.uk/delights/texts/Demonstration_09.htm

...and you may have some problems retrieving the product.

Definitely appreciated.  I can now sleep at night.