Water → 1-benzyl-4-bromo-5-(3,4-dihydro-2H-1-benzopyran-6-yl)-3-(trifluoromethyl)-1H-pyrazole

HRID 591077Notes

Reaction equation

HRID 591077 reaction equation
[CH2:1]([N:8]1[C:12]([C:13]2[CH:14]=[CH:15][C:16]3[O:21][CH2:20][CH2:19][CH2:18][C:17]=3[CH:22]=2)=[CH:11][C:10]([C:23]([F:26])([F:25])[F:24])=[N:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Br:27]N1C(=O)CCC1=O.O>C(#N)C>[CH2:1]([N:8]1[C:12]([C:13]2[CH:14]=[CH:15][C:16]3[O:21][CH2:20][CH2:19][CH2:18][C:17]=3[CH:22]=2)=[C:11]([Br:27])[C:10]([C:23]([F:26])([F:24])[F:25])=[N:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 962WaterHCID 67184N-bromobutanimideHCID 708554551-benzyl-5-(3,4-dihydro-2H-1-benzopyran-6-yl)-3-(trifluoromethyl)-1H-pyrazole

Product 1

HCID 708181471-benzyl-4-bromo-5-(3,4-dihydro-2H-1-benzopyran-6-yl)-3-(trifluoromethyl)-1H-pyrazoleYield 63%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A solution 1-benzyl-5-(3,4-dihydro-2H-1-benzopyran-6-yl)-3-(trifluoromethyl)-1H-pyrazole (49c) (260 mg, 0.73 mmol) and N-bromosuccinimide (157 mg, 0.88 mmol) in acetonitrile (5 mL) was refluxed for 45 minutes. Water (5 mL) was added, and the aqueous layer was extracted with dichloromethane (2×5 mL). The combined organics layers were dried over sodium sulfate and concentrated in vacuo. The residue was purified by preparative TLC (cyclohexane/ethyl acetate 100/0 to 90/10) to provide the 1-benzyl-4-bromo-5-(3,4-dihydro-2H-1-benzopyran-6-yl)-3-(trifluoromethyl)-1H-pyrazole (49d) (200 mg, 0.46 mmol, 63%).

Workup

  1. extractionthe aqueous layer was extracted with dichloromethane (2×5 mL)
  2. dry with materialThe combined organics layers were dried over sodium sulfate
  3. concentrationconcentrated in vacuo
  4. customThe residue was purified by preparative TLC (cyclohexane/ethyl acetate 100/0 to 90/10)

Sources & evidence

ORD record
ord-45d633aee31a495cb3b0153084432271
Source dataset
uspto-grants-2016_01
Patent number
US09238026B2

Reaction notes

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