1-(6-Chloro-3-pyridazinyl)-5-(2-pyridyl)pyrazole-3-carboxylic acid ethyl ester → methyl 1-(6-methoxy-3-pyridazinyl)-5-(2-pyridyl)-1H-pyrazole-3-carboxylate

HRID 1437264Notes

Reaction equation

HRID 1437264 reaction equation
[CH3:1][O-:2].[Na+].CO.[CH2:6]([O:8][C:9]([C:11]1[CH:15]=[C:14]([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][N:17]=2)[N:13]([C:22]2[N:23]=[N:24][C:25](Cl)=[CH:26][CH:27]=2)[N:12]=1)=[O:10])C>CO>[CH3:6][O:8][C:9]([C:11]1[CH:15]=[C:14]([C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][N:17]=2)[N:13]([C:22]2[N:23]=[N:24][C:25]([O:2][CH3:1])=[CH:26][CH:27]=2)[N:12]=1)=[O:10]

Participants

4

Reactant 2

HCID 231434631-(6-Chloro-3-pyridazinyl)-5-(2-pyridyl)pyrazole-3-carboxylic acid ethyl esterHCID 23694274Sodium methanolate methanol

Product 1

HCID 23143541methyl 1-(6-methoxy-3-pyridazinyl)-5-(2-pyridyl)-1H-pyrazole-3-carboxylate

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

28% Sodium methoxide-methanol (3 mL) was added to the above-obtained 1-(6-chloro-3-pyridazinyl)-5-(2-pyridyl)pyrazole-3-carboxylic acid ethyl ester (1.50 g) in methanol (45 mL), and the resultant mixture was refluxed under heat for 2 hours, and then cooled in air. The reaction solvent was removed under reduced pressure, and the residue was partitioned by use of ethyl acetate and saturated aqueous sodium hydrogencarbonate. The organic layer was dried over magnesium sulfate anhydrate, followed by filtration. The solvent was removed under reduced pressure, and the residue was purified through silica gel chromatography (ethyl acetate-hexane), to thereby give 1-(6-methoxy-3-pyridazinyl)-5-(2-pyridyl)pyrazole-3-carboxylic acid methyl ester as a solid (480 mg, 34%).

Workup

  1. temperatureunder heat for 2 hours
  2. temperaturecooled in air
  3. customThe reaction solvent was removed under reduced pressure
  4. customthe residue was partitioned by use of ethyl acetate and saturated aqueous sodium hydrogencarbonate
  5. dry with materialThe organic layer was dried over magnesium sulfate anhydrate
  6. filtrationfollowed by filtration
  7. customThe solvent was removed under reduced pressure
  8. customthe residue was purified through silica gel chromatography (ethyl acetate-hexane)

Sources & evidence

ORD record
ord-5d20c4f8c73e42758ea1b2ec6efdf6a0
Source dataset
uspto-grants-2009_11
Patent number
US07622471B2

Reaction notes

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