1,2-Dichloroethane → Ethyl 5-chloro-1-(pyridin-2-YL)-1H-pyrazole-4-carboxylate

HRID 1941877

Reaction equation

HRID 1941877 reaction equation
N[C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][N:8]=2)[N:5]=[CH:4][C:3]=1[C:13]([O:15][CH2:16][CH3:17])=[O:14].N(OC(C)(C)C)=O.[Cl:25]CCCl>ClCCl.[Cu](Cl)Cl>[Cl:25][C:2]1[N:6]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][N:8]=2)[N:5]=[CH:4][C:3]=1[C:13]([O:15][CH2:16][CH3:17])=[O:14]

Participants

6

Reactant 3

HCID 111,2-DichloroethaneHCID 10906Tert-Butyl nitriteHCID 742041ethyl 5-amino-1-(pyridin-2-yl)-1H-pyrazole-4-carboxylate

Product 1

HCID 13654084Ethyl 5-chloro-1-(pyridin-2-YL)-1H-pyrazole-4-carboxylate

Reagents, catalysts & solvents 2

HCID 24014Cupric ChlorideCatalystHCID 6344DichloromethaneSolvent

Procedure

To a solution of ethyl 5-amino-1-(pyridin-2-yl)-1H-pyrazole-4-carboxylate (200 mg, 0.861 mmol) and copper (II) chloride (116 mg, 0.861 mmol) in 1,2-dichloroethane (8 mL) was added tert-butyl nitrite (0.154 mL, 1.292 mmol). The reaction mixture was stirred at rt for 16 hrs. The reaction mixture was diluted with 30 mL of dichloromethane and was washed with 10 mL of 2M NH4OH solution, 10 mL of brine and dried over Na2SO4. Filtration and concentration yielded a crude product which was purified on silica gel column eluting with hexanes/EtOAc to afford ethyl 5-chloro-1-(pyridin-2-yl)-1H-pyrazole-4-carboxylate.

Workup

  1. washwas washed with 10 mL of 2M NH4OH solution, 10 mL of brine
  2. dry with materialdried over Na2SO4
  3. filtrationFiltration and concentration
  4. customyielded a crude product which
  5. customwas purified on silica gel column
  6. washeluting with hexanes/EtOAc

Sources & evidence

ORD record
ord-97f40971f07d4407938fc61034138493
Source dataset
uspto-grants-2013_03
Patent number
US08389509B2

Linked notes

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