Phosphoric Acid → Trifop

Participants

Reaction Conditions

Reaction Steps

132.5 Parts of 2-chloropropionic acid (98% strength) and 199 parts of 50% sodium hydroxide solution are added simultaneously but separately at 110°-115° C. to a solution of 254 parts of 4-(4'-trifluoromethylphenoxy)-phenol in 1,000 parts of xylene. During the addition, the reaction temperature is maintained by azeotropic distillation of water in a water trap. The addition being complete, stirring is continued for 15 minutes at 110°-115° C., the batch is cooled to 90° C. and after addition of 400 parts of water, it is stirred for a further 10 minutes at 85° C., then acidified at this temperature with 120 parts of phosphoric acid, and stirred for a further 10 minutes. After elimination of the water phase, xylene is distilled off in a water jet vacuum, and the solids are dried at 60° C. and 250 mbar. 326 parts of 2-[4'-(4" -trifluoromethylphenoxy)-phenoxy]-propionic acid are obtained. The content of pure final product is 99.6% corresponding to a yield of 99.6% of theory. The residual content of 4-(4'-trifluoromethyl-phenoxy)-phenol is 0.35%.

Provenance & Evidence