Hydrochloric Acid → 2,4,5-Trifluoro-3-methoxybenzoic acid

Beteiligte Stoffe

Reaktionsschritte

Into a 100 ml glass reactor equipped with a reflux condenser and a stirrer, 10 g (0.0397 mol) of the tetrafluorophthalic anhydride prepared in Example 3 and 20 ml of methanol were charged, and the mixture was stirred for 2 hours under reflux. After cooling, 42.8 g (0.079 mol) of a 10% methanol solution of sodium methoxide was dropwise added thereto. Then, under reflux, the mixture was stirred for one hour. Then, 15.9 g of a 10% sodium hydroxide aqueous solution was added thereto and the mixture was stirred for 12 hors under reflux. After cooling, 8 g of a 20% hydrochloric acid aqueous solution was added. Further, 21.1 g (0.0596 mol) of trioctylamine and 40 g of xylene were added thereto, and the mixture was stirred. The organic layer was separated and stirred at 140° C. for 2 hours. After completion of the reaction, 30 ml of a 20% sodium hydroxide aqueous solution was added thereto and stirred. The aqueous phase was separated and neutralized with a 10% hydrochloric acid aqueous solution and extracted with ethyl acetate. The solvent was distilled off to obtain 6.7 g of 3-methoxy-2,4,5-trifluorobenzoic acid. The yield was 81.5%.

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