Aluminium lithium hydride → 1-Methyl-4-(trifluoromethyl)-1H-pyrazole-3-methanol

HRID 1192959Notes

Reaction equation

HRID 1192959 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].[CH3:7][N:8]1[CH:12]=[C:11]([C:13]([F:16])([F:15])[F:14])[C:10]([C:17](O)=[O:18])=[N:9]1>C1COCC1>[OH:18][CH2:17][C:10]1[C:11]([C:13]([F:16])([F:15])[F:14])=[CH:12][N:8]([CH3:7])[N:9]=1

Participants

4

Reactant 2

HCID 21226445Aluminium lithium hydrideHCID 59739552HCID 59739552, compound

Product 1

HCID 575745421-Methyl-4-(trifluoromethyl)-1H-pyrazole-3-methanolYield 77%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

Lithium aluminium hydride (1M in THF) (11 ml, 11 mmol) was added dropwise to a solution of 1-methyl-4-trifluoromethyl-1H-pyrazole-3-carboxylic acid (1.94 g, 10 mmol) in THF (20 ml) under nitrogen. More THF (20 ml) was added to facilitate the stirring. After stirring for 5 hours at room temperature the reaction was quenched by addition of water (0.5 ml), 15% aqueous sodium hydroxide (0.5 ml), and more water (0.5 ml). Ethyl acetate (50 ml) and magnesium sulfate (25 g) were added and the mixture stored at room temperature for 18 hours. Kieselguhr (30 g) was added, the mixture filtered and the solids washed with ethyl acetate. The combined filtrate and washings were concentrated to give the product as a pale yellow oily solid (1.38 g, 77% yield). 1H-NMR (400 MHz, CDCl3): 2.3 (1H, bs, OH), 3.91 (3H, s, Me), 4.75 (2H, s, CH2), 7.62 (1H, s, CH).

Workup

  1. customwas quenched by addition of water (0.5 ml), 15% aqueous sodium hydroxide (0.5 ml), and more water (0.5 ml)
  2. additionEthyl acetate (50 ml) and magnesium sulfate (25 g) were added
  3. waitthe mixture stored at room temperature for 18 hours
  4. additionKieselguhr (30 g) was added
  5. filtrationthe mixture filtered
  6. washthe solids washed with ethyl acetate
  7. concentrationThe combined filtrate and washings were concentrated

Sources & evidence

ORD record
ord-c8901c0c75f9417589e583a2b04fb9b4
Source dataset
uspto-grants-2014_03
Patent number
US08680290B2

Reaction notes

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