Hydrogen Bromide → 1H-Pyrazole-5-carboxylic acid, 3-bromo-1-(3-chloro-2-pyridinyl)-4,5-dihydro-, ethyl ester

HRID 646642Notes

Reaction equation

HRID 646642 reaction equation
[BrH:1].[Cl:2][C:3]1[C:4]([N:9]2[CH:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[CH2:12][C:11](OS(C3C=CC(C)=CC=3)(=O)=O)=[N:10]2)=[N:5][CH:6]=[CH:7][CH:8]=1>BrCBr>[Br:1][C:11]1[CH2:12][CH:13]([C:14]([O:16][CH2:17][CH3:18])=[O:15])[N:9]([C:4]2[C:3]([Cl:2])=[CH:8][CH:7]=[CH:6][N:5]=2)[N:10]=1

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 22280356ethyl 1-(3-chloro-2-pyridinyl)-4,5-dihydro-3-[[(4-methylphenyl)sulfonyl]oxy]-1H-pyrazole-5-carboxylate

Product 1

HCID 100653831H-Pyrazole-5-carboxylic acid, 3-bromo-1-(3-chloro-2-pyridinyl)-4,5-dihydro-, ethyl esterYield 100%

Reagents, catalysts & solvents 1

HCID 3024DibromomethaneSolvent

Procedure

Hydrogen bromide was passed through a solution of ethyl 1-(3-chloro-2-pyridinyl)-4,5-dihydro-3-[[(4-methylphenyl)sulfonyl]oxy]-1H-pyrazole-5-carboxylate (i.e. product of Step A) (5 g, 11.8 mmol) in dibromomethane (50 mL). After about 60 minutes the gas flow was terminated, and the reaction mixture was washed with aqueous sodium bicarbonate solution (50 mL). The organic phase was dried and evaporated under reduced pressure to give the title product as an oil (3.92 g, 100% yield), which crystallized on standing. The 1H NMR spectrum of the product was the same as reported for the product of Example 1, Step C.

Workup

  1. customAfter about 60 minutes the gas flow was terminated
  2. washthe reaction mixture was washed with aqueous sodium bicarbonate solution (50 mL)
  3. customThe organic phase was dried
  4. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-987e9803742948ffbe91edbea4910cbb
Source dataset
uspto-grants-2010_04
Patent number
US07705160B2

Reaction notes

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