Bromobenzene → 4-Bromobenzaldehyde

HRID 2228387Notes

Reaction equation

HRID 2228387 reaction equation
C([C:4]1[CH:9]=[CH:8][C:7]([CH:10]2[O:14]CCO2)=[C:6]([SiH](C)C)[CH:5]=1)C=C.B1C2CCCC1CCC2.C1C=CC([Br:33])=CC=1.C([O-])([O-])=O.[Na+].[Na+].[Al]>C1COCC1.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.CN(C=O)C>[Br:33][C:4]1[CH:9]=[CH:8][C:7]([CH:10]=[O:14])=[CH:6][CH:5]=1

Participants

9

Reactant 5

HCID 7961BromobenzeneHCID 10340Sodium CarbonateHCID 789669-Borabicyclo(3.3.1)nonaneHCID 5359268AluminumHCID 1317233722-(4-Allyldimethylsilylphenyl)1,3-dioxolane

Product 1

HCID 707414-BromobenzaldehydeYield 3%

Reagents, catalysts & solvents 3

HCID 178418397HCID 178418397, compoundCatalyst2×HCID 6228DimethylformamideSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution 2-(4-allyldimethylsilylphenyl)-1,3-dioxolane (3 Scheme 18, 456 mg, 2 mmol) in dry THF (10 mL) under a N2 atmosphere was added 9-BBN (4 mL, 0.5 M solution in THF, 2 mmol) dropwise at 0° C. The mixture was gradually warmed to room temperature and stirred for 5 h. Pd(PPh3)4 (70 mg), 4-bromopolystyrene (500 mg, 1.94 mmol/g), 2 N aqueous Na2CO3 (2 mL, 4 mmol), DMF (5 mL), were added. The reaction flask and reflux condenser were wrapped with aluminum foil, and the mixture was refluxed for 24 h. Pd(PPh3)4 (70 mg) was added to the reaction mixture which was refluxed again for 24 h. The resin was filtered and washed with THF (once), 1:1 THF/water (twice), water (twice), methanol (twice), CH2Cl2 (twice), then dried under reduced pressure. The resin (4 Scheme 18) was agitated in THF/1 N HCl (8:1) for 16 h at 30° C. After washing and drying, an aliquot of the resin (200 mg) was treated with a solution of CH2Cl2 (7 mL) and Br2 (150 μL) for 5 min. The cleavage solution was removed, and the resin was rinsed with CH2Cl2 (3 mL). Concentration of the combined filtrates gave the known 4-bromobenzaldehyde (1 Scheme 18, 11 mg, loading level was determined to be 0.30 mequiv/g); 1H NMR (300 MHz, CDCl3) δ 7.71 (d, J=8.30 Hz, 2 H), 7.77 (d, J=8.30 Hz, 2 H), 10.00 (s, 1 H).

Workup

  1. temperatureThe reaction flask and reflux condenser
  2. temperaturethe mixture was refluxed for 24 h
  3. temperaturewas refluxed again for 24 h
  4. filtrationThe resin was filtered
  5. washwashed with THF (once), 1:1 THF/water (twice), water (twice), methanol (twice), CH2Cl2 (twice),
  6. customthen dried under reduced pressure
  7. stirringThe resin (4 Scheme 18) was agitated in THF/1 N HCl (8:1) for 16 h at 30° C
  8. washAfter washing
  9. customdrying
  10. additionan aliquot of the resin (200 mg) was treated with a solution of CH2Cl2 (7 mL) and Br2 (150 μL) for 5 min
  11. customThe cleavage solution was removed
  12. washthe resin was rinsed with CH2Cl2 (3 mL)

Sources & evidence

ORD record
ord-60a91fbd5337455aa1f20d65de7375d3
Source dataset
uspto-grants-2002_07
Patent number
US06416861B1

Reaction notes

Loading…