Ethanol → 5-Bromo-2-(3'-bromophenyl)-pyridine

HRID 43253Notes

Reaction equation

HRID 43253 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Br:8])=[CH:4][N:3]=1.[Br:9][C:10]1[CH:11]=[C:12](B(O)O)[CH:13]=[CH:14][CH:15]=1.C([O-])([O-])=O.[Na+].[Na+].CCO>[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.C1(C)C=CC=CC=1>[Br:8][C:5]1[CH:6]=[CH:7][C:2]([C:14]2[CH:13]=[CH:12][CH:11]=[C:10]([Br:9])[CH:15]=2)=[N:3][CH:4]=1

Participants

7

Reactant 4

HCID 702EthanolHCID 10340Sodium CarbonateHCID 693532,5-DibromopyridineHCID 2734318(3-Bromophenyl)boronic acid

Product 1

HCID 672133855-Bromo-2-(3'-bromophenyl)-pyridine

Reagents, catalysts & solvents 2

HCID 11979704Tetrakis(triphenylphosphine)palladiumCatalystHCID 1140TolueneSolvent

Conditions

Temperature
105 °C

Procedure

A mixture of 2,5-dibromopyridine (4.33 g, 17.7 mmol), 3-bromophenylboronic acid (4.70 g, 21.3 mmol), tetrakis(triphenylphosphine) palladium (0) (800 mg, 0.692 mmol), 2 M Na2CO3(aq) (18 cm3), EtOH (18 cm3) and toluene (50 cm3) was degassed and heated at reflux with a bath temperature of 105° C. under argon for 23 h. The reaction was allowed to cool and the two phases were separated. The aqueous layer was extracted with ether (3×15 cm3). The organic layer and the ether extracts were combined, washed with brine (1×40 cm3) and dried over anhydrous sodium sulfate. The solvents were completely removed to leave an orange oil. The oil was purified by column chromatography over silica gel using DCM-light petroleum (0:1 to 1:10) as eluent to give 2.50 g (45%) of B-1 as a pale yellow solid; δH(200 MHz; CDCl3) 7.26-7.42 (1 H, m, ArH), 7.57 (2 H, m, PyH & ArH), 7.88 (2 H, m, PyH & ArH), 8.14 (1 H, m, ArH), and 8.74 (1 H, m, PyH); m/z [CI(NH3)] 312, 314, 316 (MH+).

Workup

  1. customwas degassed
  2. temperatureheated
  3. temperatureto cool
  4. customthe two phases were separated
  5. extractionThe aqueous layer was extracted with ether (3×15 cm3)
  6. washwashed with brine (1×40 cm3)
  7. dry with materialdried over anhydrous sodium sulfate
  8. customThe solvents were completely removed
  9. customto leave an orange oil
  10. customThe oil was purified by column chromatography over silica gel
  11. customto give 2.50 g (45%) of B-1 as a pale yellow solid

Sources & evidence

ORD record
ord-58ce276ab8234d1c933d6fbbba510b7a
Source dataset
uspto-grants-2013_09
Patent number
US08536333B2

Reaction notes

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