colorless or clear yellow oily liquid. decompose with water and alcohol, soluble in ether, chloroform and benzene.
Phthaloyl chloride is used for the preparation of volatile acid chlorides from the acids. It acts as a trapping agent for the nitrite ion in the fluorodenitration of aromatic substrates with potassium fluoride. It serves as an additive in polymers and fibers to improve the color stability. It is used as an ingredient in ceramic mold binders, as a stabilizer for polymers and in reverse osmosis membranes.
o-Phthaloyl Dichloride is used in the phthaloylation of hemicelluloses as an efficient way to improve their lipophilicity and hydrophilicity. Phthaloylation of hemicelluloses is also a key precursor to preparing polysaccharide derivatives.
Synthesis of phthaloyl dichloride: Mix 148g of phthalic anhydride with 220g of phosphorus pentachloride, heat, gradually increase the temperature to 250°C, escape the phosphorus oxychloride, distill the reaction product under reduced pressure, collect the 131-133°C (1.2-1.33kPa) fraction to obtain 187g of phthaloyl dichloride.
equilibrium mixture (phthaloyl chloride ~80% and pseudochloride ~10%) both components show equal chemical behaviour
