Process for the preparation of triflic a nhydride
AssigneeEastman Chemical Company
InventorsRobert Thomas Hembre, Robert Lin
Life of this patent
Estimating the term…
Abstract
Disclosed is a process for the preparation of trifluoromethanesulfonic acid anhydride by the steps of (1) forming a mixed anhydride comprising a trifluoromethanesulfonyl acyl residue and a carboxyl residue by contacting trifluoromethanesulfonic acid or a derivative thereof with a carboxyl compound selected from ketene, dialkyl ketenes, carboxylic acids, and derivatives of carboxylic acids and (2) subjecting the mixed anhydride to reactive distillation wherein the mixed anhydride undergoes disproportionation to produce triflic anhydride and a higher boiling carboxylic acid anhydride.
Claims14
Process for the coproduction of trifluoromethanesulfonic acid anhydride and a carboxylic acid anhydride which comprises the steps of:
- (1) forming a mixed anhydride comprising a trifluoromethanesulfonyl acyl residue and a carboxyl residue by contacting trifluoromethanesulfonic acid (triflic acid) or an acid halide thereof with a carboxyl compound selected from ketene, dialkyl ketenes, carboxylic acids, salts of carboxylic acids, and carboxylic acid halides;
- and
- (2) subjecting the mixed anhydride to reactive distillation to produce triflic anhydride and a higher boiling carboxylic acid anhydride.
Process for the coproduction of trifluoromethanesulfonic acid anhydride (triflic anhydride) and a carboxylic acid anhydride which comprises the steps of:
- (1) introducing a ketene reactant and triflic acid to a reaction vessel wherein the ketene reactant and triflic acid react to form a product comprising a mixed anhydride;
- (2) removing product from the reaction vessel and introducing it into the mid-section of a reactive distillation column wherein the mixed anhydride disproportionates to form triflic anhydride and a carboxylic acid anhydride;
- (3) removing triflic anhydride from the upper section of the reactive distillation column;
- and (4) removing a carboxylic anhydride from the lower section of the reactive distillation column.
Process for the coproduction of trifluoromethanesulfonic acid anhydride (triflic anhydride) and a carboxylic acid anhydride which comprises the steps of (1) preparing in a reaction vessel a mixed anhydride having the formula
- F3CSO2—O—C(O)-R (I)
- wherein R represents the residue of an aliphatic carboxylic acid containing from 2 to 8 carbon atoms;
- (2) removing product from the reaction vessel and introducing it into the mid-section of a reactive distillation column wherein the mixed anhydride disproportionates to form triflic anhydride and a carboxylic anhydride;
- (3) removing triflic anhydride from the upper section of the reactive distillation column;
- and (4) removing a carboxylic anhydride from the lower section of the reactive distillation column.
Process for the coproduction of trifluoromethanesulfonic acid anhydride (triflic anhydride) and a carboxylic anhydride which comprises the steps of:
- (1) introducing a ketene reactant and trifluoromethanesulfonic acid (triflic acid) acid directly into a reactive distillation column wherein the ketene reactant and triflic acid react to form a mixed anhydride which disproportionates to form triflic anhydride and a carboxylic anhydride;
- (2) removing triflic anhydride from the upper section of the reactive distillation column;
- and (3) removing a carboxylic anhydride from the lower section of the reactive distillation column.
Dependencies are inferred from the claim text.