Potassium Phosphate, Tribasic → 2,5-diphenylpyridine

HRID 1522697Notes

Reaction equation

HRID 1522697 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5](Br)=[CH:4][N:3]=1.[C:9]1(B(O)O)[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1.P([O-])([O-])([O-])=O.[K+].[K+].[K+]>C1(C)C=CC=CC=1.O.C1(P(C2CCCCC2)C2C=CC=CC=2C2C(OC)=CC=CC=2OC)CCCCC1>[C:9]1([C:2]2[CH:7]=[CH:6][C:5]([C:9]3[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=3)=[CH:4][N:3]=2)[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1

Participants

7

Reactant 3

HCID 62657Potassium Phosphate, TribasicHCID 66827Phenylboronic AcidHCID 693532,5-Dibromopyridine

Product 1

HCID 27628582,5-diphenylpyridineYield 91.8%

Reagents, catalysts & solvents 3

HCID 112698722-Dicyclohexylphosphino-2',6'-dimethoxybiphenylCatalystHCID 962WaterSolventHCID 1140TolueneSolvent

Procedure

2,5-dibromopyridine (10 g, 42 mmol), phenylboronic acid (13.4 g, 110 mmol), dicyclohexyl(2′,6′-dimethoxybiphenyl-2-yl)phosphine (S-Phos) (0.7 g, 1.6 mmol), and potassium phosphate (22 g, 105 mmol) were mixed in 200 mL of toluene and 20 mL of water. Nitrogen is bubbled directly into the mixture for 30 minutes. Next, Pd2(dba)3 was added (0.38 g, 0.4 mmol) and the mixture was heated to reflux under nitrogen for 2 h. The mixture was cooled and the organic layer was separated. The organic layers are washed with brine, dried over magnesium sulfate, filtered, and evaporated to a residue. The residue was purified by column chromatography eluting with 10% ethyl acetate/hexanes. 7 g of desired product was obtained after purification. (91.8% yield)

Workup

  1. customNitrogen is bubbled directly into the mixture for 30 minutes
  2. additionNext, Pd2(dba)3 was added (0.38 g, 0.4 mmol)
  3. temperaturethe mixture was heated
  4. temperatureto reflux under nitrogen for 2 h
  5. temperatureThe mixture was cooled
  6. customthe organic layer was separated
  7. washThe organic layers are washed with brine
  8. dry with materialdried over magnesium sulfate
  9. filtrationfiltered
  10. customevaporated to a residue
  11. customThe residue was purified by column chromatography
  12. washeluting with 10% ethyl acetate/hexanes

Sources & evidence

ORD record
ord-0b7fabd46dad473dbdda8f8f70c9c2a3
Source dataset
uspto-grants-2015_07
Patent number
US09076973B2

Reaction notes

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