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

HRID 2057108Notes

Reaction equation

HRID 2057108 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-carboxylate2×

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-657656e0ab0f4312ab23d1a55ce73ed7
Source dataset
uspto-grants-2008_02
Patent number
US07335780B2

Reaction notes

Loading…