1H-Pyrazole-4-carboxylic acid, 1-methyl-3-(trifluoromethyl)-, ethyl ester → (1-Methyl-3-(trifluoromethyl)-1H-pyrazol-4-yl)methanol

HRID 220452Notes

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.[H-].C([Al+]CC(C)C)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

Conditions

Temperature: 0 °C

Procedure

Dissolve 1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid ethyl ester (1.74 g, 7.83 mmol) in tetrahydrofuran (100 mL) and cool to 0° C. Add diisobutylaluminum hydride (47.0 mL, 47.0 mmol, 1 M in toluene) dropwise over 15 min. Allow the reaction mixture to warm to room temperature over 16 hr. Partition between ethyl acetate (100 mL) and saturated aqueous potassium sodium tartrate solution (50 mL) and stir at room temperature for another 16 hr. Separate the organic layer; dry (sodium sulfate), filter and concentrate to give (1-methyl-3-trifluoromethyl-1H-pyrazol-4-yl)-methanol (1.42 g, 100%). 1H-NMR (400 MHz, CDCl3) δ 7.42 (s, 1H), 4.63 (s, 2H), 3.90 (s, 3H), 1.80 (bs, 1H).

Workup

temperatureto warm to room temperature over 16 hr
customPartition between ethyl acetate (100 mL) and saturated aqueous potassium sodium tartrate solution (50 mL)
customSeparate the organic layer
dry with materialdry (sodium sulfate)
filtrationfilter
concentrationconcentrate

Sources & evidence

ORD record: ord-0aa726c3ef0d4080b5e28c319872e619
Source dataset: uspto-grants-2012_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08202873B2

Reaction notes

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