Sulfuric Acid → 4-Bromo-1-cyclopentyl-2-(trifluoromethyl)benzene

HRID 2040585Notes

Reaction equation

HRID 2040585 reaction equation
[CH:1]1([C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[C:12]([F:15])([F:14])[F:13])[CH2:5][CH2:4][CH2:3][CH2:2]1.[Br:16]Br.OS(O)(=O)=O>C(O)(=O)C>[Br:16][C:9]1[CH:10]=[CH:11][C:6]([CH:1]2[CH2:2][CH2:3][CH2:4][CH2:5]2)=[C:7]([C:12]([F:13])([F:14])[F:15])[CH:8]=1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 24408BromineHCID 591465321-Cyclopentyl-2-(trifluoromethyl)benzene

Product 1

HCID 672111474-Bromo-1-cyclopentyl-2-(trifluoromethyl)benzeneYield 36.5%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a solution of 1-cyclopentyl-2-(trifluoromethyl)benzene (0.5 g, 2.334 mmol) in acetic acid (2.5 mL) was added bromine (1.202 mL, 23.34 mmol). The mixture was stirred well, added concentrated H2SO4 (2.5 mL), and stirred at 40° C. for 1.5 h. The reaction mixture was poured into ice-water and extracted with CH2Cl2. The CH2Cl2 layer was washed with water, followed by a solution of sodium thiosulfate, then with water. The organic layer was dried over Na2SO4 and the solvent was removed under reduced pressure. The residue was purified by silica gel chromatography to give the title compound (250 mg). 1H NMR (400 MHz, DMSO-d6) δ ppm 1.52-1.75 (m, 4H), 1.78-1.88 (m, 2H), 1.95-2.04 (m, 2H), 3.16-3.26 (m, 1H), 7.57 (d, J=8.4 Hz, 1H), 7.76 (d, J=2 Hz, 1H), 7.81 (dd, J=8.4 Hz, 2 Hz, 1H).

Workup

  1. stirringstirred at 40° C. for 1.5 h
  2. extractionextracted with CH2Cl2
  3. washThe CH2Cl2 layer was washed with water
  4. dry with materialThe organic layer was dried over Na2SO4
  5. customthe solvent was removed under reduced pressure
  6. customThe residue was purified by silica gel chromatography

Sources & evidence

ORD record
ord-2c3b9219de9b42839caa701b839fd937
Source dataset
uspto-grants-2013_11
Patent number
US08580841B2

Reaction notes

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