Diisopropylethylamine → ethyl 1-(5-fluoropyridin-2-yl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate

HRID 1506537

Reaction equation

C(O/[CH:4]=[C:5](\[C:11](=O)[C:12]([F:15])([F:14])[F:13])/[C:6]([O:8][CH2:9][CH3:10])=[O:7])C.C(N(C(C)C)CC)(C)C.F.[F:27][C:28]1[CH:29]=[CH:30][C:31]([NH:34][NH2:35])=[N:32][CH:33]=1>C(O)C>[F:27][C:28]1[CH:29]=[CH:30][C:31]([N:34]2[C:11]([C:12]([F:13])([F:14])[F:15])=[C:5]([C:6]([O:8][CH2:9][CH3:10])=[O:7])[CH:4]=[N:35]2)=[N:32][CH:33]=1

Participants

Conditions

Temperature: 80 °C

Procedure

To (E)-ethyl 2-(ethoxymethylene)-4,4,4-trifluoro-3-oxobutanoate (0.441 g, 1.835 mmol) in ethanol (2 mL) was added diisopropylethylamine (0.427 mL, 2.447 mmol) followed by 5-fluoro-2-hydrazinylpyridine, hydrofluoride (0.3 g, 2.039 mmol) dissolved in 1 mL of ethanol (slightly exothermic). The reaction mixture was heated at 80° C. for 1 h. The reaction mixture was concentrated under reduced pressure, dissolved in dichloromethane (2 mL) and subjected to column chromatography using an ISCO setup (40 g, RediSep® silica gel column). The desired fractions were collected and concentrated to yield ethyl 1-(5-fluoropyridin-2-yl)-5-(trifluoromethyl)-1H-pyrazole-4-carboxylate (0.165 g, 27%) as a white solid. LC/MS M+1=304.

Workup

concentrationThe reaction mixture was concentrated under reduced pressure
dissolutiondissolved in dichloromethane (2 mL)
customThe desired fractions were collected
concentrationconcentrated

Sources & evidence

ORD record: ord-a4f8b5e232224f2db07a166844118c3d
Source dataset: uspto-grants-2015_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09216972B2

Linked notes

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