Diisobutylaluminum hydride → (1,3-dimethyl-1H-pyrazol-4-yl)methanol

HRID 2111906Notes

Reaction equation

HRID 2111906 reaction equation
C([O:3][C:4]([C:6]1[C:7]([CH3:12])=[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]([CH3:12])=[N:8]1

Participants

4

Reactant 2

HCID 14487Diisobutylaluminum hydrideHCID 10313289ethyl 1,3-dimethyl-1H-pyrazole-4-carboxylate

Product 1

HCID 949772(1,3-dimethyl-1H-pyrazol-4-yl)methanolYield 100%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

To a cooled solution (0° C.) of 1,3-dimethyl-1H-pyrazole-4-carboxylic acid ethyl ester (5.0 g, 29.7 mmol) in anhydrous tetrahydrofuran (1000 ml), is added a solution of DIBAL-H (95.1 ml, 95.1 mmol). The reaction mixture is stirred at 0° C. for 2 hours and then quenched with saturated aqueous sodium potassium tartrate and stirred for 2 hours. The layers are separated and the aqueous layer is extracted with ethyl acetate. The combined organic extracts are dried over anhydrous Na2SO4, filtered, and concentrated in vacuo to give 1,3-dimethyl-1H-pyrazol-4-methanol (3.7 g, 100%) which is used without purification. 1H NMR (CDCl3): δ=7.22 (1H, s), 4.46 (2H, s), 3.74 (3H, s), 2.20 (3H, s).

Workup

  1. customquenched with saturated aqueous sodium potassium tartrate
  2. stirringstirred for 2 hours
  3. customThe layers are separated
  4. extractionthe aqueous layer is extracted 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-06fc9185d0f1490684127883d0e49999
Source dataset
uspto-grants-2009_04
Patent number
US07521462B2

Reaction notes

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