Sodium Carbonate → 3-(4-hydroxyphenyl)-4H-chromen-4-one

HRID 418880Notes

Reaction equation

HRID 418880 reaction equation
Br[C:2]1[C:11](=[O:12])[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[O:4][CH:3]=1.C[O:14][C:15]1[CH:20]=[CH:19][C:18](B(O)O)=[CH:17][CH:16]=1.C(=O)([O-])[O-].[Na+].[Na+].Cl.[NH+]1C=CC=CC=1.C([O-])(O)=O.[Na+]>O.C1(C)C=CC=CC=1>[OH:14][C:15]1[CH:20]=[CH:19][C:18]([C:2]2[C:11](=[O:12])[C:10]3[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=3)[O:4][CH:3]=2)=[CH:17][CH:16]=1

Participants

8

Reactant 5

HCID 10340Sodium CarbonateHCID 201262(4-Methoxyphenyl)boronic acidHCID 516892Sodium BicarbonateHCID 5212563-BromochromoneHCID 21584435Pyridinium hydrochloride

Product 1

HCID 109665513-(4-hydroxyphenyl)-4H-chromen-4-oneYield 83%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent3×HCID 1140TolueneSolvent

Conditions

Temperature
110 °C

Procedure

To a mixture of 3-bromochromone (1.5 g, 6.66 mmol), 4-methoxy phenyl boronic acid (1.01 g, 6.66 mmol), sodium carbonate (2.12 g, 20.0 mmol), toluene (40 mL) and water (10 mL) was added tetrakis-triphenyl phosphine palladium (385 mg, 0.33 mmol) under N2. The reaction mixture was heated to 110° C. for 5 h and then cooled to rt. Water was added and the mixture was extracted with EtOAc. The organic layer was separated, washed with water, brine, dried and concentrated to give crude product, which was purified by column chromatography, using 20% EtOAc in hexane to give, 885 mg of 4′-methoxychromone product in 52% yield. A mixture of the above mentioned 4′-methoxychromone (400 mg, 1.58 mmol) and pyridinium hydrochloride (5 g) was heated at 190° C. for 4 h. The reaction mixture was cooled to rt, diluted with water, neutralized with NaHCO3 and filtered to give 314 mg of 3-(4-hydroxyphenyl)-4H-chromen-4-one (83%). MS (ES) m/z: 239.95 (M+1), 238.99 (M); Mp. 237-238° C.

Workup

  1. temperaturecooled to rt
  2. extractionthe mixture was extracted with EtOAc
  3. customThe organic layer was separated
  4. washwashed with water, brine
  5. customdried
  6. concentrationconcentrated
  7. customto give crude product, which
  8. customwas purified by column chromatography
  9. customto give
  10. additionA mixture of the
  11. temperaturewas heated at 190° C. for 4 h
  12. temperatureThe reaction mixture was cooled to rt
  13. filtrationfiltered

Sources & evidence

ORD record
ord-bcd9cf6583cc4586a5ab924fce839190
Source dataset
uspto-grants-2012_01
Patent number
US08093273B2

Reaction notes

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