Synthesis Of The Phthaloyl Dichloride

This paper relates to a process for producing isophthaloyl dichloride or terephthaloyl dichloride of high purity. Various methods have been suggested for producing the isophthaloyl dichloride or terephthaloyl dichloride, a method for producing which comprises chlorinating m-xylene or p-xylene of its methyl groups to from hexachloroxylene, and reacting the resulting hexachloroxylene with isophthalic acid or terephthalic acid is especially advantageous from an economic standpoint.The synthesis process conditions were investigated and it was concluded that when m-xylene chlorine ratio is 1:8,the reaction temperature is 130℃,and while irradiating light by a 18 W.A gas-chromatographic analysis of this product showed that the concentration of hexachloro-m-xylene was 92.2%.A mixture of 31.3g(corresponding to about 0.1 mole, because the molecular weight of hexachloro-m-xylene is 313)of the crude hexachloro-m-xylene obtained in above,16.6g(0.1 mole)of isophthalic acid and 0.05 g of anhydrous ferric chloride was heated with strring.at about 80℃,The total yield of the purified isophthaloyl dichloride based on the starting m-xylene was 90.3%.The synthesis process conditions were investigated and it was concluded that when p-xylene chlorine ratio is 1:10,the reaction temperature is 145℃,and while irradiating light by a 25 W.A gas-chromatographic analysis of this product showed that the concentration of hexachloro-p-xylene was 95.5%.A mixture of 31.3g(corresponding to about 0.1 mole, because the molecular weight of hexachloro-p-xylene is 313)of the crude hexachloro-p-xylene obtained in above,16.6g(0.1 mole)of terephthalic acid and 0.05 g of anhydrous ferric chloride was heated with strring.at about 100 ℃,The total yield of the purified terephthaloyl dichloride based on the starting p-xylene was 95.5%.Isophthaloyl dichloride and terephaloyl dichloride were analyzed by melting point, IR Spectrum, 1H-NMR and GC-MS.their purity reached 99.9%.