| 摘要 |
A process of azeotropic removal of dimethylformamide, abbreviated as DMF, from a process stream containing DMF requiring its removal, is described wherein the said Process Stream being obtained in a process for preparation of 4,1',6' trichlorogalactosucrose, abbreviated as TGS, or TGS-6-ester including TGS-6-acetate or TGS-6-benzoate, comprising steps of (a) evaporation of the said process stream under reduced pressure to a concentrate to effect removal of a part of DMF azeotropically, (b) diluting the concentrate obtained at the end of step (a.) of this claim with water, preferably to about 5 to 10 times the volume of the said concentrate, and (c) repeating the cycles of evaporation under reduced pressure and dilution with water for more number of times until content of DMF in the concentrated mass is reduced to 0.5% or less of the concentrate.
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