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

HRID 1043470Notes

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-52fb3ad297ab4c07845a81f24968c623
Source dataset: uspto-grants-2013_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08563541B2

Reaction notes

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