[Chris_Whewell]

I need to produce azelayl monochloride.  As you know, azelaic acid is a nine-carbon linear aliphatic dicarboxylic acid.  I need the monoacyl halide.

A reference to a prep would be very helpful.

I attempted adding 0.1 mol azelaic acid to toluene; unfortunately the solubility of azelaic in toluene is limited.  Nevertheless, I added 0.1 mol thionyl chloride to the mixture, followed by the addition of a tertiary amine.  There was a slight exotherm, up to about 45 C.   However, things are not looking very nice.  Perhaps a different solvent ?  

[movies]

I think that usually these reactions are done with dichloromethane solvent and a catalytic amount of N,N-dimethylformamide (DMF).  When I have made acid chlorides this way, the reaction is usually very clean (although I would usually use oxalyl chloride in stead of thionyl chloride.

At any rate, it might be difficult to get the mono-acid chloride.  I would susupect that you would get a statistical mixture of products.