2-Chlorophenylhydrazine hydrochloride → 5-(4-bromo-phenyl)-1-(2-chloro-phenyl)-3-pentafluoroethyl-4,5-dihydro-1H-pyrazole

HRID 2207865Notes

Reaction equation

[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]=[CH:9][C:10](=O)[C:11]([F:17])([F:16])[C:12]([F:15])([F:14])[F:13])=[CH:4][CH:3]=1.Cl.[Cl:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][C:22]=1[NH:27][NH2:28]>C(O)(=O)C>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH:8]2[N:27]([C:22]3[CH:23]=[CH:24][CH:25]=[CH:26][C:21]=3[Cl:20])[N:28]=[C:10]([C:11]([F:17])([F:16])[C:12]([F:15])([F:14])[F:13])[CH2:9]2)=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 125 °C

Procedure

1-(4-Bromo-phenyl)-4,4,5,5,5-pentafluoro-pent-1-en-3-one (8.0 g, 24.3 mmol) prepared in Step 2 and 2-chlorophenylhydrazine hydrochloride (5.7 g, 31.6 mmol) were added to acetic acid (116.0 mL). The reaction mixture was stirred at 125° C. for 4 hours, concentrated under reduced pressure, and then ethyl acetate was added thereto. The mixture was washed with a saturated solution of sodium hydrogen carbonate, dried on anhydrous magnesium sulfate, and then concentrated under reduced pressure to give a yellow liquid residue. The resulting residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane=1/60) to give 8.5 g of the titled compound as a yellow liquid.

Workup

concentrationconcentrated under reduced pressure
additionethyl acetate was added
washThe mixture was washed with a saturated solution of sodium hydrogen carbonate
dry with materialdried on anhydrous magnesium sulfate
concentrationconcentrated under reduced pressure
customto give a yellow liquid residue
customThe resulting residue was purified by silica gel column chromatography (eluent: ethyl acetate/n-hexane=1/60)

Sources & evidence

ORD record: ord-91ea71e40d6646c5b95656e306523acd
Source dataset: uspto-grants-2016_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09376420B2

Reaction notes

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