Process for the manufacture of light colored dipropyleneglycol dibenzoate

摘要

Process for production of dipropyleneglycol dibenzoate isomer mixture of the formulas: <IMAGE> <IMAGE> +TR <IMAGE> A crude methyl benzoate containing at least 80 wt.% methylbenzoate, which is a by-product of production of dimethylterephthalate by catalytic oxidation of p-xylene and/or methyl-p-toluate and esterification of the resulting acids with methanol, is contacted with dipropylene glycol commercial isomer mixture in the presence of a catalyst for a transesterification to produce said benzoate. The catalyst is an aluminum alkoxide or an aluminum silicon alkoxide containing the group Al O Si. The product is obtained in good yield, has good color, and is useful as a plasticizer for PVC.