Lithium Hydroxide → 5-Bromo-6-(4-chloro-phenyl)-3-trifluoromethyl-pyrazine-2-carboxylic acid

HRID 416469Notes

Reaction equation

HRID 416469 reaction equation
C[O:2][C:3]([C:5]1[C:10]([C:11]([F:14])([F:13])[F:12])=[N:9][C:8]([Br:15])=[C:7]([C:16]2[CH:21]=[CH:20][C:19]([Cl:22])=[CH:18][CH:17]=2)[N:6]=1)=[O:4].[OH-].[Li+]>O1CCCC1.O>[Br:15][C:8]1[N:9]=[C:10]([C:11]([F:14])([F:13])[F:12])[C:5]([C:3]([OH:4])=[O:2])=[N:6][C:7]=1[C:16]1[CH:21]=[CH:20][C:19]([Cl:22])=[CH:18][CH:17]=1

Participants

5

Reactant 2

HCID 3939Lithium HydroxideHCID 866347025-Bromo-6-(4-chloro-phenyl)-3-trifluoromethyl-pyrazine-2-carboxylic acid methyl ester

Product 1

HCID 462210845-Bromo-6-(4-chloro-phenyl)-3-trifluoromethyl-pyrazine-2-carboxylic acidYield 74.6%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 7.7 g 5-bromo-6-(4-chloro-phenyl)-3-trifluoromethyl-pyrazine-2-carboxylic acid methyl ester in 50 ml tetrahydrofuran was added at 0° C. 20 ml of a 1M solution of lithium hydroxide in water. The cooling bath was removed and the mixture was stirred at ambient temperature for 20 min. The orange reaction mixture was partitioned between heptane and water. The phases were separated the aqueous phase was mixed with ethyl acetate and 10% aqueous citric acid whereby the yellow orange color almost disappeared. The phases were separated and the organic phase was washed with brine dried over sodium sulfate, evaporated and dried under high vacuum to yield 5.54 g of the title compound as yellow solid. This material was recrystallized from ethyl acetate/heptane before use. MS (M−H) at 381.1 and 379.1.

Workup

  1. customThe cooling bath was removed
  2. customThe orange reaction mixture was partitioned between heptane and water
  3. customThe phases were separated the aqueous phase
  4. additionwas mixed with ethyl acetate and 10% aqueous citric acid whereby the yellow orange color
  5. customThe phases were separated
  6. washthe organic phase was washed with brine
  7. dry with materialdried over sodium sulfate
  8. customevaporated
  9. customdried under high vacuum

Sources & evidence

ORD record
ord-2fbb98cb80f245389b606bed640bbb76
Source dataset
uspto-grants-2012_01
Patent number
US08088920B2

Reaction notes

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