Dimethyl phthalate is known to be an effective and safe repellent for blood sucking insects like mosquitoes and flies. It finds extensive application as a plasticizer, as a carrier in the dyeing of synthetic polyesters, as a froth flotation agent and an ingredient in hair sprays.
Generally, dimethylphthalate is obtained by direct oxidation of hydrocarbons. Reference may be made to “Chemical Abstract (CA) Vol. 43, (1949) 5767a”. wherein phthalic anhydride and chloro sulphonic acid were refluxed. But very low yield was the drawback of the process.
Reference may be made to Ind. Engg. Chem 40,96 (1948) wherein oxides of aluminium, manganese and lead were used as catalyst. Low yield was the main drawback of the process.
Prior art search for producing dimethyl phthalate was made based on literature survey and patent data bases, which did not yield any relevant references.