Aluminium lithium hydride → HCID 86761825, compound

HRID 2090965Notes

Reaction equation

HRID 2090965 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([N:9]2[CH:13]=[C:12]([C:14](OC)=[O:15])[C:11]([CH2:18][CH3:19])=[N:10]2)[CH:5]=[C:6]([F:8])[CH:7]=1.[H-].[Al+3].[Li+].[H-].[H-].[H-]>O1CCCC1.C1(C)C=CC=CC=1.[O-2].[O-2].[Mn+4]>[F:8][C:6]1[CH:5]=[C:4]([N:9]2[CH:13]=[C:12]([CH:14]=[O:15])[C:11]([CH2:18][CH3:19])=[N:10]2)[CH:3]=[C:2]([F:1])[CH:7]=1

Participants

6

Reactant 2

HCID 21226445Aluminium lithium hydrideHCID 86761822HCID 86761822, compound2×

Product 1

HCID 86761825HCID 86761825, compoundYield 53.8%

Reagents, catalysts & solvents 3

HCID 178418406HCID 178418406, compoundCatalystHCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

A solution (35 mL) of methyl 1 (3,5-difluorophenyl)-3-ethyl-1H-pyrazole-4-carboxylate (6.5 g) synthesized in the above-mentioned (1) in tetrahydrofuran was added to an ice-cooled solution (65 mL) of lithium aluminum hydride (0.94 g) in tetrahydrofuran. The ice bath was removed, and the reaction mixture was stirred at room temperature for 1 hr. The mixture was ice-cooled again, and water (2.5 mL), 1N aqueous sodium hydroxide solution (12.5 mL) and water (2.5 mL) were successively added dropwise to quench the reaction. The residue was filtered through celite, and the filtrate was concentrated under reduced pressure to give a crude product (3.3 g) of 1-(3,5-difluorophenyl)-3-ethyl-1H-pyrazole-4-methanol as a pale-yellow oil. This was dissolved in toluene (100 mL), manganese dioxide (6.0 g) was added, and the mixture was heated under reflux with a Dean-Stark trap for 1 hr. The reaction mixture was allowed to cool to room temperature, manganese dioxide was collected by filtration, and the solvent was evaporated under reduced pressure to give the title object compound (3.1 g, 51%) as a yellow solid.

Workup

  1. customThe ice bath was removed
  2. temperaturecooled again
  3. additionwater (2.5 mL), 1N aqueous sodium hydroxide solution (12.5 mL) and water (2.5 mL) were successively added dropwise
  4. customto quench
  5. customthe reaction
  6. filtrationThe residue was filtered through celite
  7. concentrationthe filtrate was concentrated under reduced pressure
  8. customto give a crude product (3.3 g) of 1-(3,5-difluorophenyl)-3-ethyl-1H-pyrazole-4-methanol as a pale-yellow oil
  9. temperaturethe mixture was heated
  10. temperatureunder reflux with a Dean-Stark trap for 1 hr
  11. temperatureto cool to room temperature
  12. filtrationmanganese dioxide was collected by filtration
  13. customthe solvent was evaporated under reduced pressure

Sources & evidence

ORD record
ord-2a4fbc9a48d54c549dfb73652647617d
Source dataset
uspto-grants-2013_05
Patent number
US08436043B2

Reaction notes

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