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

HRID 2057106Notes

Reaction equation

HRID 2057106 reaction equation
[BrH:1].Cl[C:3]1[CH2:7][CH:6]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[N:5]([C:13]2[C:18]([Cl:19])=[CH:17][CH:16]=[CH:15][N:14]=2)[N:4]=1>BrCBr>[Br:1][C:3]1[CH2:7][CH:6]([C:8]([O:10][CH2:11][CH3:12])=[O:9])[N:5]([C:13]2[C:18]([Cl:19])=[CH:17][CH:16]=[CH:15][N:14]=2)[N:4]=1

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 11701977HCID 11701977, compound2×

Product 1

HCID 100653831H-Pyrazole-5-carboxylic acid, 3-bromo-1-(3-chloro-2-pyridinyl)-4,5-dihydro-, ethyl esterYield 99%

Reagents, catalysts & solvents 1

HCID 3024DibromomethaneSolvent

Procedure

Hydrogen bromide was passed through a solution of ethyl 3-chloro-1-(3-chloro-2-pyridinyl)-4,5-dihydro-1H-pyrazole-5-carboxylate (i.e. product of Step B) (8.45 g, 29.3 mmol) in dibromomethane (85 mL). After 90 minutes the gas flow was terminated, and the reaction mixture was washed with aqueous sodium bicarbonate solution (100 mL). The organic phase was dried and evaporated under reduced pressure to give the title product as an oil (9.7 g, 99% yield), which crystallized on standing.

Workup

  1. customAfter 90 minutes the gas flow was terminated
  2. washthe reaction mixture was washed with aqueous sodium bicarbonate solution (100 mL)
  3. customThe organic phase was dried
  4. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-170d01168d3c40158ce5ceb4f173ae15
Source dataset
uspto-grants-2008_02
Patent number
US07335780B2

Reaction notes

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