METHOD FOR PREPARING TRIFLUOROMETHANE SULFOACID ANHYDRIDE Russian patent published in 2006 - IPC C07C309/00 C07C303/22 

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for synthesis of trifluoromethane sulfoacid (TFMSA) anhydride used in synthesis of trifluoromethane sulfoacid, in fine organic synthesis, producing drugs, fungicides, extractants and catalysts. Method involves dehydration of trifluoromethane sulfoacid with phosphorus (V) pentoxide taken in the mole ratio TFMSA : P₂O₅ = 1.0:(0.7-1.0) at stirring, distillation of liquid products formed from mixture of trifluoromethane sulfoacid and phosphorus (V) pentoxide at temperature of mixture 95-130°C and under pressure lower atmospheric pressure 150-200 mm of mercury column followed addition inert gas to the system and utilization of vat residue remained after distillation of trifluoromethane sulfoacid wherein the dehydration process is combined with distillation of crude trifluoromethane sulfoacid anhydride from the reaction mixture that then is distilled again in the presence of silicon oxide and phosphorus (V) pentoxide and at babbling inert gas at temperature 69-71°C and under pressure 580-600 mm of mercury column.

EFFECT: improved method of synthesis.

3 cl, 1 tbl