Sodium Hydroxide → 2,5-bis(2,2,2-trifluoroethoxy)benzoic Acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 7.3 moles (292 g.) of sodium hydroxide in 600 ml. of water is added ice to make the total volume of 1.75 liters. Chlorine gas is passed into the solution while maintaining the temperature below 10° C. until it is neutral to litmus, and 2.19 moles (87.6 g.) of sodium hydroxide dissolved in 200 ml. of water is added. The combined solution is warmed to 50° C., and 0.73 mole (230 g.) of 2,5-bis(2,2,2-trifluoroethoxy)acetophenone is added slowly. The reaction mixture is stirred while heating until an exotherm begins about 75° C. and is thereafter maintained at about 80° C. by cooling. The mixture is stirred for about 16 hours at about 80° to 90° C. while monitoring the extent of the reaction by thin-layer chromatography. The excess hypochlorite is then destroyed by adding 75 g. of sodium bisulfite in 250 ml. of water, and the mixture is cooled to about 25° C. and carefully acidified with 10 percent hydrochloric acid. The light yellow solid product is collected by filtration, washed with water, and dried. A 94.5 percent yield of 2,5-bis(2,2,2-trifluoroethoxy)benzoic acid, m.p 120° to 122° C., is obtained.

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