PROCESS FOR CARBOXYBENZALDEHYDE FROM RESIDUE OF DIMETHYLTEREPHTHALATE

摘要

Dimethylterephthalate(DMT) residue by distillation which consists mainly of methylparaformylbenzoate(MFB) was melted in solvent and added with Na2S2O5 soln. or NaHSO3 soln. to give solid product which is filtrated at -10-100 deg.C. Fitrated material was washed with solvent having a wt. ratio of 1:1 based on MFB and melted in boiling water and reacted with inorg. acid such as sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid with a mol. ratio 1:0.1-100. After the decomposition and hydrolysis of obtained material, precipitate was cooled, filtrated washed and dried to give a final product. This material uses intermediates in manufacturing of sensitizer, fluorescent bleaches and antiseptic.