You could try acetyl chloride. You might have to make it if you can't get it, apparently you can make acetyl chloride from acetic acid, acetonitrile, and HCl. You should also be able to make it using phosphorous chloride reactions, since that's a general method for conversion of carboxylic acids to acyl chlorides. See here (replace [DOT] with period, and of course, clearnet link: https://chem.libretexts[DOT]org/Bookshelves/Organic_Chemistry/Supplemental_Modules_(Organic_Chemistry)/Acid_Halides/Synthesis_of_Acid_Halides/Preparation_of_Acyl_Chlorides The only thing is the above methods apparently often produce a product contaminated with phosphorous impurities. You could make dichloroacetyl chloride and react that with acetic acid to get acetyl chloride. You can synthesize the dichlorozacetyl chloride by oxidation of 1,1,2-trichloroethane, carboxylation of chloroform, or hydrolysis of pentachloroethane. It's a real bitch I had some pure morphine a one point but was never able to do the conversion because there was just always something I ran into that I couldn't get, or there was a reaction or workup that was too much to do in a home lab