Allyltributylstannane → methyl 2-(5-allyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)acetate

HRID 1471657Notes

Reaction equation

Br[C:2]1[N:6]([CH2:7][C:8]([O:10][CH3:11])=[O:9])[N:5]=[C:4]([C:12]([F:15])([F:14])[F:13])[CH:3]=1.[CH2:16]([Sn](CCCC)(CCCC)CC=C)[CH2:17][CH2:18]C>CN(C=O)C.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[CH2:18]([C:2]1[N:6]([CH2:7][C:8]([O:10][CH3:11])=[O:9])[N:5]=[C:4]([C:12]([F:15])([F:14])[F:13])[CH:3]=1)[CH:17]=[CH2:16]

Participants

Conditions

Temperature: 120 °C

Procedure

Methyl 2-(5-bromo-3-(trifluoromethyl)-1H-pyrazol-1-yl)acetate (420 mg, 1.47 mmol), tri n-butyl allyltin (729 mg, 2.20 mmol) and tetrakis(triphenylphosphine)palladium(0) (50 mg, 0.043 mmol) were dissolved in DMF (10 mL). The solution was degassed with argon for 10 min and then heated at 120° C. overnight. After the solution was cooled to room temperature, the volatiles were removed under vacuum. The resulting residue was purified by silica gel chromatography (loading with toluene, eluting with dichloromethane/hexanes) to afford methyl 2-(5-allyl-3-(trifluoromethyl)-1H-pyrazol-1-yl)acetate (140 mg, 38%) as a clear oil. MS (m/z): 249.1 [M+H]+; HPLC retention time 3.51 min (2-98% acetonitrile:water with 0.05% trifluoroacetic acid).

Workup

customThe solution was degassed with argon for 10 min
temperatureAfter the solution was cooled to room temperature
customthe volatiles were removed under vacuum
customThe resulting residue was purified by silica gel chromatography (loading with toluene, eluting with dichloromethane/hexanes)

Sources & evidence

ORD record: ord-089d328bb3dd4ff783572a85ed76f749
Source dataset: uspto-grants-2015_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09012441B2

Reaction notes

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