4-chloro-3-(2,4-difluoro-5-nitrophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrazole → 5-(4-chloro-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)-2,4-difluorobenzenamine

HRID 1440137Notes

Reaction equation

[Cl:1][C:2]1[C:3]([C:12]2[CH:17]=[C:16]([N+:18]([O-])=O)[C:15]([F:21])=[CH:14][C:13]=2[F:22])=[N:4][N:5]([CH3:11])[C:6]=1[C:7]([F:10])([F:9])[F:8]>C(O)(=O)C.[Fe]>[Cl:1][C:2]1[C:3]([C:12]2[C:13]([F:22])=[CH:14][C:15]([F:21])=[C:16]([NH2:18])[CH:17]=2)=[N:4][N:5]([CH3:11])[C:6]=1[C:7]([F:9])([F:8])[F:10]

Participants

Conditions

Temperature: 80 °C

Procedure

A solution of 3.4 g (0.01 mole) 4-chloro-3-(2,4-difluoro-5-nitrophenyl)-1-methyl-5-(trifluoromethyl)-1H-pyrazole in 50 mL acetic acid was heated to 80° C. under a nitrogen atmosphere. The heat and nitrogen were removed and 1.7 g (0.03 mole) iron powder was added in 3 portions over 5 min. The solution was stirred at 80° C. for an additional 30 min. The solution was cooled and filtered through Celite®. The filtrate was diluted with 100 mL water and extracted three times with ethyl acetate. The ethyl acetate extracts were washed with a saturated NaHCO3 solution, dried over anhydrous MgSO4, and concentrated in vacuo. The residue was purified chromatographically using 35% ethyl acetate in hexane as the eluent to give 2.46 g (79%) of 5-(4-chloro-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl)-2,4-difluorobenzenamine as a white solid, mp 82° C.

Workup

temperatureThe heat
customnitrogen were removed
temperatureThe solution was cooled
filtrationfiltered through Celite®
additionThe filtrate was diluted with 100 mL water
extractionextracted three times with ethyl acetate
washThe ethyl acetate extracts were washed with a saturated NaHCO3 solution
dry with materialdried over anhydrous MgSO4
concentrationconcentrated in vacuo
customThe residue was purified chromatographically

Sources & evidence

ORD record: ord-0b8e275e61274893bcd5a2d2cb19a85c
Source dataset: uspto-grants-1996_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05496956

Reaction notes

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