Reaction #42056

Reaction equation

sodium bromate

sodium hydrogensulfite

4-methyl-3-trifluoromethylbenzoic acid

isopropyl acetate

→

objective compound

Yield 60.1%

4-(bromomethyl)-3-trifluoromethylbenzoic acid

Yield 60.1%

Solvents

water

water

Conditions

Workup

1. 1
   TemperatureThe mixture was gradually heated from 30° C. up to 50° C. at intervals of 10° C.
2. 2
   workup.STIRRINGstirred until the color of the reaction solution
3. 3
   OtherThe aqueous layer was separated
4. 4
   Otherto remove
5. 5
   workup.ADDITIONto the organic layer were added a solution of 133.0 g of sodium bromate in 420 ml of water
6. 6
   Temperaturea solution of 91.7 g of sodium hydrogensulfite in 180 ml of water, and then the mixture was gradually heated up to 60° C. as above
7. 7
   OtherAfter separation
8. 8
   workup.ADDITIONto the organic layer were further added a solution of 133.0 g of sodium bromate in 420 ml of water
9. 9
   Temperaturea solution of 91.7 g of sodium hydrogensulfite in 180 ml of water, and the mixture was gradually heated as above and
10. 10
    Temperatureheated to the temperature the mixture
11. 11
    Temperaturewas finally refluxed
12. 12
    OtherAfter the completion of the reaction
13. 13
    Otherthe reaction solution was separated
14. 14
    Washthe organic layer was washed twice with a 5% aqueous sodium thiosulfate solution and twice with 15% saline
15. 15
    Dryingdried over anhydrous magnesium sulfate
16. 16
    workup.DISTILLATIONthe solvent was distilled off under reduced pressure
17. 17
    workup.ADDITIONTo the residue was added 120 ml of n-heptane
18. 18
    workup.STIRRINGthe mixture was stirred
19. 19
    Filtrationthe crystals were collected by filtration

Procedure

To 60.0 g of 4-methyl-3-trifluoromethylbenzoic acid was added 600 ml of isopropyl acetate. Under stirring at room temperature, a solution of 133.0 g of sodium bromate in 420 ml of water and a solution of 91.7 g of sodium hydrogensulfite in 180 ml of water were added in turn. The mixture was gradually heated from 30° C. up to 50° C. at intervals of 10° C. and stirred until the color of the reaction solution disappeared. The aqueous layer was separated to remove, and to the organic layer were added a solution of 133.0 g of sodium bromate in 420 ml of water and a solution of 91.7 g of sodium hydrogensulfite in 180 ml of water, and then the mixture was gradually heated up to 60° C. as above. After separation, to the organic layer were further added a solution of 133.0 g of sodium bromate in 420 ml of water and a solution of 91.7 g of sodium hydrogensulfite in 180 ml of water, and the mixture was gradually heated as above and heated to the temperature the mixture was finally refluxed. After the completion of the reaction, the reaction solution was separated, the organic layer was washed twice with a 5% aqueous sodium thiosulfate solution and twice with 15% saline, dried over anhydrous magnesium sulfate, and, then the solvent was distilled off under reduced pressure. To the residue was added 120 ml of n-heptane, the mixture was stirred, and then the crystals were collected by filtration to obtain 50.0 g of the objective compound as colorless crystals.

Source