Reaction #347145

Reaction equation

hydrochloric acid

sodium hydroxide

trioctylamine

sodium methoxide

tetrafluorophthalic anhydride

→

3-methoxy-2,4,5-trifluorobenzoic acid

Yield 81.5%

Solvents

xylene

methanol

methanol

Conditions

Workup

1. 1
   OtherInto a 100 ml glass reactor equipped with a reflux condenser and a stirrer
2. 2
   Temperatureunder reflux
3. 3
   TemperatureAfter cooling
4. 4
   TemperatureThen, under reflux
5. 5
   workup.STIRRINGthe mixture was stirred for one hour
6. 6
   workup.STIRRINGthe mixture was stirred for 12 hors
7. 7
   Temperatureunder reflux
8. 8
   TemperatureAfter cooling
9. 9
   workup.STIRRINGthe mixture was stirred
10. 10
    OtherThe organic layer was separated
11. 11
    workup.STIRRINGstirred at 140° C. for 2 hours
12. 12
    OtherAfter completion of the reaction, 30 ml of a 20% sodium hydroxide aqueous solution
13. 13
    workup.ADDITIONwas added
14. 14
    workup.STIRRINGstirred
15. 15
    OtherThe aqueous phase was separated
16. 16
    Extractionextracted with ethyl acetate
17. 17
    workup.DISTILLATIONThe solvent was distilled off

Procedure

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%.

Source