Hydrochloric Acid → HCID 19365505, compound

HRID 849958Notes

Reaction equation

HRID 849958 reaction equation
C(=O)([O-])[O-].[Na+].[Na+].Br[CH:8](Br)[C:9]([C:11]([F:14])([F:13])[F:12])=O.[NH2:16][CH:17]([C:21]1[CH:26]=[CH:25][C:24]([F:27])=[CH:23][C:22]=1[F:28])[C:18]([NH2:20])=[O:19].Cl>O>[F:28][C:22]1[CH:23]=[C:24]([F:27])[CH:25]=[CH:26][C:21]=1[C:17]1[C:18](=[O:19])[NH:20][C:9]([C:11]([F:14])([F:13])[F:12])=[CH:8][N:16]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 10340Sodium CarbonateHCID 5505231,1-Dibromo-3,3,3-trifluoroacetoneHCID 19365521HCID 19365521, compound

Product 1

HCID 19365505HCID 19365505, compound

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

To a mixed solution of 121 g of sodium carbonate and 400 ml of water was added dropwise 77.1 g of 1,1-dibromo-3,3,3-trifluoroacetone at such a rate that the temperature of the reaction mixture became not higher than 55° C. After completion of the dropwise addition, the mixture was stirred at room temperature for 30 minutes, followed by adding 500 ml of water and then 40 g of 2-amino-2-(2,4-difluorophenyl)acetamide, and the reaction was allowed to proceed at 60° C. for 2 hours. After completion of the reaction, the reaction mixture was cooled to 10° C. or lower, made acidic by adding 80 ml of concentrated hydrochloric acid at the same temperature, and extracted with ethyl acetate. The organic layer was washed with water and then saturated sodium chloride solution, dried with anhydrous magnesium sulfate, and concentrated. The residue was subjected to silica gel column chromatography (eluent, hexane/ethyl acetate=4:1), which afforded 23.3 g (yield, 39%) of the desired compound, 3-(2,4-difluorophenyl)-6-trifluoromethyl-2-oxo-1,2-dihydropyrazine (compound 1-1004; m.p., 178.9° C.). The continued elution with the above solvent system gave 13.2 g of the configurational isomer, 3-(2,4-difluorophenyl)-5-trifluoromethyl-2-oxo-1,2-dihydropyrazine (m.p., 164.6° C.).

Workup

  1. custombecame not higher than 55° C
  2. additionAfter completion of the dropwise addition
  3. waitto proceed at 60° C. for 2 hours
  4. customAfter completion of the reaction
  5. temperaturethe reaction mixture was cooled to 10° C.
  6. extractionextracted with ethyl acetate
  7. washThe organic layer was washed with water
  8. dry with materialsaturated sodium chloride solution, dried with anhydrous magnesium sulfate
  9. concentrationconcentrated
  10. customafforded

Sources & evidence

ORD record
ord-3ea63cc21d024b178fe059026837a605
Source dataset
uspto-grants-2000_01
Patent number
US06015774

Reaction notes

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