Dimethylformamide → 3-(difluoromethyl)-5-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-4-carbaldehyde

HRID 75219Notes

Reaction equation

Br[C:2]1[C:3]([CH:14]([F:16])[F:15])=[N:4][N:5]([CH:8]2[CH2:13][CH2:12][CH2:11][CH2:10][O:9]2)[C:6]=1[CH3:7].[O:17]1CCC[CH2:18]1.C([Li])CCC.CN(C)C=O>CCCCCC>[F:15][CH:14]([F:16])[C:3]1[C:2]([CH:18]=[O:17])=[C:6]([CH3:7])[N:5]([CH:8]2[CH2:13][CH2:12][CH2:11][CH2:10][O:9]2)[N:4]=1

Participants

Conditions

Temperature: -78 °C

Procedure

A solution of 4-bromo-3-(difluoromethyl)-5-methyl-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole (0.60 g, 2.0 mmol) in tetrahydrofuran (7.00 mL, 86.3 mmol) was cooled at −78° C. Into the reaction was added 1.6 M of n-butyllithium in hexane (2.00 mL) and was stirred at −78° C. for 5 min. N,N-Dimethylformamide (0.31 mL, 4.1 mmol) was added and stirred at −78° C. for 1 h. The reaction was extracted with ethyl acetate and the organic extracts were washed with water, saturated NaCl, dried (MgSO4) and concentrated in vacuo. The crude product was used in the next reaction without further purification. 1H NMR (CDCl3): δ 10.12 (s, 1H), 6.81-6.95 (t, 1H), 5.38 (m, 1H), 4.03 (m, 1H), 3.68 (m, 1H), 2.66 (s, 3H), 2.42 (m, 1H), 2.14 (m, 1H), 1.96 (m, 1H), 1.50-1.75 (m, 3H).

Workup

stirringstirred at −78° C. for 1 h
extractionThe reaction was extracted with ethyl acetate
washthe organic extracts were washed with water, saturated NaCl
dry with materialdried (MgSO4)
concentrationconcentrated in vacuo
customThe crude product was used in the next reaction without further purification

Sources & evidence

ORD record: ord-9278ea9c6ee34c04892a51e17f946437
Source dataset: uspto-grants-2014_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08835423B2

Reaction notes

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