1,3-Dibromobenzene → 3-(3-Bromophenyl)pyridine

HRID 985509Notes

Reaction equation

HRID 985509 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([Br:8])[CH:3]=1.C(B(CC)[C:12]1[CH:13]=[N:14][CH:15]=[CH:16][CH:17]=1)C.[OH-].C([N+](CCCC)(CCCC)CCCC)CCC.C(=O)([O-])[O-].[Na+].[Na+]>O.COCCOC.C(OCC)(=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>[Br:8][C:4]1[CH:3]=[C:2]([C:12]2[CH:13]=[N:14][CH:15]=[CH:16][CH:17]=2)[CH:7]=[CH:6][CH:5]=1

Participants

9

Reactant 4

HCID 79271,3-DibromobenzeneHCID 10340Sodium CarbonateHCID 6428513-(Diethylboryl)pyridineHCID 2723671Tetrabutylammonium Hydroxide

Product 1

HCID 131504013-(3-Bromophenyl)pyridineYield 70.2%

Reagents, catalysts & solvents 4

HCID 178418397HCID 178418397, compoundCatalystHCID 962WaterSolventHCID 80711,2-DimethoxyethaneSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

A mixture of 1,3-dibromobenzene (105.0 g, 0.45 mol), diethyl(3-pyridyl)borane (30.0 g, 0.204 mol) and tetrabutylammonium hydroxide (2 ml of a 40 wt % solution in water) in 1,2-dimethoxyethane (200 ml) and sodium carbonate (100 ml of a 2M solution) was degassed with nitrogen for 15 min before addition of tetrakis(triphenylphosphine)palladium(0) (4.5 g, 3.9 mmol). The mixture was heated at 80° C. for 18 h, cooled to room temperature, diluted with ethyl acetate and extracted with 1M hydrochloric acid (4×250 ml). The combined aqueous phases were made basic with solid sodium hydroxide and then extracted with diethyl ether. The organic layer was washed with water, brine, dried over sodium sulphate and concentrated to give a yellow oil. Purification by silica gel chromatography eluting with isohexane on a gradient of diethyl ether (10% to 50%) gave 3-(3-bromophenyl)pyridine (33.5 g, 70%) as a colourless oil. 1H NMR (400 MHz, CDCl3) δH 7.28-7.40 (2H, m), 7.48-7.57 (2H, m), 7.73 (1H, t, J 2), 7.82-7.87 (1H, m), 8.62 (1H, s), 8.80 (1H, s).

Workup

  1. temperaturecooled to room temperature
  2. extractionextracted with 1M hydrochloric acid (4×250 ml)
  3. extractionextracted with diethyl ether
  4. washThe organic layer was washed with water, brine
  5. dry with materialdried over sodium sulphate
  6. concentrationconcentrated
  7. customto give a yellow oil
  8. customPurification by silica gel chromatography
  9. washeluting with isohexane on a gradient of diethyl ether (10% to 50%)

Sources & evidence

ORD record
ord-a95685a4acc944f3b630a5912cfec11b
Source dataset
uspto-grants-2005_03
Patent number
US06872731B2

Reaction notes

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