Potassium Carbonate → ethyl 6-(trifluoromethyl)-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate

HRID 1448472Notes

Reaction equation

HRID 1448472 reaction equation
C(=O)([O-])[O-].[K+].[K+].[NH2:7][C:8]1[CH:13]=[C:12]([C:14]([F:17])([F:16])[F:15])[CH:11]=[CH:10][C:9]=1[OH:18].Br[CH:20]([CH2:26]Br)[C:21]([O:23][CH2:24][CH3:25])=[O:22]>CC(C)=O>[F:17][C:14]([F:15])([F:16])[C:12]1[CH:11]=[CH:10][C:9]2[O:18][CH:20]([C:21]([O:23][CH2:24][CH3:25])=[O:22])[CH2:26][NH:7][C:8]=2[CH:13]=1

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 97945Ethyl 2,3-dibromopropionateHCID 1202462-Amino-4-(trifluoromethyl)phenol

Product 1

HCID 11747775ethyl 6-(trifluoromethyl)-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

11.4 g of potassium carbonate was added to 48.7 g of 7B in 320 ml of acetone. Then 18.2 of ethyl 2,3-dibromopropionate was added dropwise to the refluxing mixture. This procedure was repeated thrice. The mixture was refluxed for 17 hours and filtered, and the filtrate was stripped of solvent under reduced pressure. The residue was dissolved in ether; the solution was washed with dilute sodium hydroxide solution, then dried (MgSO4) and stripped of solvent. The residue was washed with petroleum ether and dried. The residue was mixed with ether and filtered. Part of the solvent was evaporated from the filtrate; the remaining solution was cooled. Crystals which formed were filtered and recrystallized from ether to give 7, m.p.: 105°-107°.

Workup

  1. temperatureThe mixture was refluxed for 17 hours
  2. filtrationfiltered
  3. dissolutionThe residue was dissolved in ether
  4. washthe solution was washed with dilute sodium hydroxide solution
  5. dry with materialdried (MgSO4)
  6. washThe residue was washed with petroleum ether
  7. customdried
  8. additionThe residue was mixed with ether
  9. filtrationfiltered
  10. customPart of the solvent was evaporated from the filtrate
  11. temperaturethe remaining solution was cooled
  12. customCrystals which formed
  13. filtrationwere filtered
  14. customrecrystallized from ether
  15. customto give 7, m.p.: 105°-107°

Sources & evidence

ORD record
ord-a749377ba5bf43f5b37a59353094a98a
Source dataset
uspto-grants-1979_12
Patent number
US04180572

Reaction notes

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