Diisobutylaluminum hydride → (1-Methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)methanol

HRID 2111908Notes

Reaction equation

HRID 2111908 reaction equation
C([O:3][C:4]([C:6]1[C:7]([C:12]([F:15])([F:14])[F:13])=[N:8][N:9]([CH3:11])[CH:10]=1)=O)C.CC(C[AlH]CC(C)C)C>O1CCCC1>[CH3:11][N:9]1[CH:10]=[C:6]([CH2:4][OH:3])[C:7]([C:12]([F:13])([F:14])[F:15])=[N:8]1

Participants

4

Reactant 2

HCID 14487Diisobutylaluminum hydrideHCID 27829701H-Pyrazole-4-carboxylic acid, 1-methyl-3-(trifluoromethyl)-, ethyl ester

Product 1

HCID 21039553(1-Methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)methanolYield 123.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

To a cooled solution (0° C.) of 1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid ethyl ester (1.0 g, 4.5 mmol) in anhydrous tetrahydrofuran (50 ml), is added a solution of DIBAL-H (20.3 ml, 20.3 mmol). The reaction mixture is stirred at 0° C. for 2 hours and then quenched with saturated aqueous sodium potassium tartrate and stirred for 1 hr. The layers are separated and the aqueous layer is extracted 2 times with ethyl acetate. The combined organic extracts are dried over anhydrous Na2SO4, filtered, and concentrated in vacuo to give 1-methyl-3-trifluoromethyl-1H-pyrazol-4-methanol (1.0 g, 98%) which is used without purification. 1H NMR (CDCl3): δ=7.43 (1H, s), 4.63 (2H, s), 3.90 (3H, s), 2.38 (1H, brs).

Workup

  1. customquenched with saturated aqueous sodium potassium tartrate
  2. stirringstirred for 1 hr
  3. customThe layers are separated
  4. extractionthe aqueous layer is extracted 2 times with ethyl acetate
  5. dry with materialThe combined organic extracts are dried over anhydrous Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-829c60b3bf914b318ac04bb1392fa235
Source dataset
uspto-grants-2009_04
Patent number
US07521462B2

Reaction notes

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