[Rishi]

I need to synthesize aromatic oximes of ketons (Benzophenone, Propiophenone, Acetophenone etc). I started with reaction of the ketones with Hydroxylamine hydrochloride by refluxing in alcohol. But somehow am getting lesser conversions by TLC. I took NaOH for neutralizing the HCl and also it is suggested as a catalyst. Are there any better catalysts which can be easy to separat and give higher conversions ?

Can anybody suggest a method which might give better conversions and proper isolation technique ? 

[bolo]

These oximes don't seem to be a kind of stable compounds. As you know any acidic conditions may rearrange (Beckmann) your product. But as far as I know, i.e. benzyloxyamine generates more stable oxime derivative with acetophenone or any similar. There are many descriptions of preparation you can use, for example:

Osadchenko, M.; Tomilov, A. P. Russian Journal of Applied Chemistry, 2002, 75 (3), 511-512.
DOI: 10.1023/A:1016140131717

[orgopete]

You should be able to find conditions for oxime formation in a book for laboratory procedures. (It is definitely in Shriner and Fuson, my old text.)

The most favorable conditions are acidic, approximately pH 4. Lower will tie up the hydroxylamine and higher will slow loss of water to form oxime, I presume.