| 摘要 |
The present invention results to an improved and environment friendly method of producing dimethyl phthalate of about 99% purity from naphthalene based chemicals, said method comprising steps of mixing phthalic anhydride with methanol in the ratio ranging between 2:3 to 3:2, adding catalyst(s) to the mixture wherein, the ratio of phthalic anhydride and the catalyst is ranging between 3:1 to 15:1, adding a promoter to the resultant of step (b) wherein, the promoter is in the range of 1.5 to 2.0% by weight of phthalic anhydride, refluxing the resulted mixture at a temperature ranging between 60 to 100° C., for time duration ranging between 6 to 12 hrs. in the presence of benzene, wherein the ratio of benzene phthalic anhydride is in the range of 1:5 to 2:1 to obtain distillate, neutralizing the residue with about 10% caustic soda, extracting the neutralized residue with the benzene, distilling at the temperature ranging between 140 to 150° C. under 10 mm of mercury to obtain dimethyl phthalate.
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