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

HRID 478257Notes

Reaction equation

HRID 478257 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4]([Br:8])[CH:3]=1.B1([C:15]2[CH:20]=[CH:19][CH:18]=[N:17][CH:16]=2)OCCCO1.C([O-])([O-])=O.[Na+].[Na+]>CCO.C1(C)C=CC=CC=1.[Pd].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>[Br:8][C:4]1[CH:3]=[C:2]([C:15]2[CH:16]=[N:17][CH:18]=[CH:19][CH:20]=2)[CH:7]=[CH:6][CH:5]=1

Participants

7

Reactant 3

HCID 79271,3-DibromobenzeneHCID 10340Sodium CarbonateHCID 41980053-(1,3,2-Dioxaborinan-2-yl)pyridine

Product 1

HCID 131504013-(3-Bromophenyl)pyridineYield 64%

Reagents, catalysts & solvents 3

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalystHCID 702EthanolSolventHCID 1140TolueneSolvent

Procedure

A mixture of 1,3-dibromobenzene (8.7 g, 36.8 mmol) and pyridine-3-boronic acid-1,3-propanediol cyclic ester (4.0 g, 24.5 mmol) in EtOH (60 ml) and toluene (60 ml) together with 2N Na2CO3 solution (24.5 ml) was degassed with a stream of N2 for 10 min. Tetrakis(triphenylphosphine)-palladium(0) (0.25 g, 0.22 mmol) was added and the reaction heated at reflux for 14 h. The mixture was concentrated under reduced pressure to remove the organic solvents. The organics were extracted with EtOAc (2×125 ml) and then washed with brine (75 ml), dried (MgSO4), and concentrated under reduced pressure. The resulting crude residue was purified by column chromatography on silica, using 80% diethyl ether in hexane as the eluent, to yield 3-(3-bromophenyl)pyridine (3.66 g, 64%): δH (360 MHz, CDCl3) 7.30-7.42 (2H, m), 7.47-7.60 (2H, m), 7.72 (1H, s), 7.84 (1H, dt, J 8 and 2), 8.62 (1H, dd, J 4.8 and 1.5), 8.83 (1H, s).

Workup

  1. customwas degassed with a stream of N2 for 10 min
  2. temperaturethe reaction heated
  3. temperatureat reflux for 14 h
  4. concentrationThe mixture was concentrated under reduced pressure
  5. customto remove the organic solvents
  6. extractionThe organics were extracted with EtOAc (2×125 ml)
  7. washwashed with brine (75 ml)
  8. dry with materialdried (MgSO4)
  9. concentrationconcentrated under reduced pressure
  10. customThe resulting crude residue was purified by column chromatography on silica

Sources & evidence

ORD record
ord-e91d7de382ff436fb7ddd94312242971
Source dataset
uspto-grants-2003_11
Patent number
US06642229B2

Reaction notes

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