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

HRID 646644Notes

Reaction equation

HRID 646644 reaction equation
[Cl:1][C:2]1[C:3]([N:8]2[CH:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH2:11][C:10](OS(C3C=CC=CC=3)(=O)=O)=[N:9]2)=[N:4][CH:5]=[CH:6][CH:7]=1.[BrH:28].C(=O)([O-])O.[Na+]>C(O)(=O)C>[Br:28][C:10]1[CH2:11][CH:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[N:8]([C:3]2[C:2]([Cl:1])=[CH:7][CH:6]=[CH:5][N:4]=2)[N:9]=1

Participants

5

Reactant 3

HCID 260Hydrogen BromideHCID 516892Sodium BicarbonateHCID 866008331H-Pyrazole-5-carboxylic acid, 1-(3-chloro-2-pyridinyl)-4,5-dihydro-3-[(phenylsulfonyl)oxy]-, ethyl ester

Product 1

HCID 100653831H-Pyrazole-5-carboxylic acid, 3-bromo-1-(3-chloro-2-pyridinyl)-4,5-dihydro-, ethyl esterYield 85%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Procedure

A solution of ethyl 1-(3-chloro-2-pyridinyl)-4,5-dihydro-3-[(phenylsulfonyl)oxy]-1H-pyrazole-5-carboxylate (i.e. the product of Step A) (1.0 g, 2.44 mmol) in acetic acid (4 mL) was added to a solution of hydrogen bromide in acetic acid (33%, 1.2 g, 4.89 mmol). After about 1 h the reaction mixture was added to saturated aqueous sodium hydrogen carbonate solution (100 mL). The mixture was then extracted with ethyl acetate (2×50 mL), and the combined extracts were dried (MgSO4) and evaporated to provide the title product as an oil (0.69 g, 85% yield), which slowly crystallized. The 1H NMR spectrum was the same as reported for the product of Example 1, Step C.

Workup

  1. extractionThe mixture was then extracted with ethyl acetate (2×50 mL)
  2. dry with materialthe combined extracts were dried (MgSO4)
  3. customevaporated

Sources & evidence

ORD record
ord-1995a83dc79a44ad8bb587a12e964764
Source dataset
uspto-grants-2010_04
Patent number
US07705160B2

Reaction notes

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