Hydrochloric Acid → 2-(3-fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine-3-carboxylic Acid

HRID 1280411Notes

Reaction equation

HRID 1280411 reaction equation
[OH-].[Na+].C[O:4][C:5]([C:7]1[C:8]([C:18]2[CH:23]=[CH:22][CH:21]=[C:20]([F:24])[CH:19]=2)=[N:9][N:10]2[C:15]=1[CH:14]=[CH:13][C:12]([O:16][CH3:17])=[N:11]2)=[O:6].Cl>C(O)C>[F:24][C:20]1[CH:19]=[C:18]([C:8]2[C:7]([C:5]([OH:6])=[O:4])=[C:15]3[N:10]([N:11]=[C:12]([O:16][CH3:17])[CH:13]=[CH:14]3)[N:9]=2)[CH:23]=[CH:22][CH:21]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 14798Sodium HydroxideHCID 570178562-(3-fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine-3-carboxylic Acid Methyl Ester

Product 1

HCID 225623402-(3-fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine-3-carboxylic AcidYield 91.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

2N sodium hydroxide (50 ml) was added to a solution of 2-(3-fluoro-phenyl)-6-methoxy-pyrazolo[1,5-b]pyridazine-3-carboxylic acid methyl ester (2.3 g) in absolute ethanol (50 ml) and the resulting mixture heated to reflux for three hours. The cooled reaction mixture was poured slowly into a stirred solution of 2N hydrochloric acid (300 ml). The resulting suspension was stirred at ambient temperature for 1 hour then filtered and the filter cake washed with water and dried in vacuo at 600 to give the title compound as an off-white solid (2.0 g, 91%).

Workup

  1. temperaturethe resulting mixture heated
  2. temperatureto reflux for three hours
  3. customThe cooled reaction mixture
  4. filtrationthen filtered
  5. washthe filter cake washed with water
  6. customdried in vacuo at 600

Sources & evidence

ORD record
ord-0f7df32302da4c72a135d818eb4f73e2
Source dataset
uspto-grants-2002_09
Patent number
US06451794B1

Reaction notes

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