2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 2-Bromo-1-naphthaldehyde

HRID 369757Notes

Reaction equation

HRID 369757 reaction equation
[Br:1][C:2]1[CH2:11][CH2:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3]=1[CH:12]=[O:13].C(C1C(=O)C(Cl)=C(Cl)C(=O)C=1C#N)#N>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:11]=[CH:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3]=1[CH:12]=[O:13]

Participants

4

Reactant 2

HCID 67752,3-Dichloro-5,6-dicyano-1,4-benzoquinoneHCID 639798HCID 639798, compound

Product 1

HCID 114476722-Bromo-1-naphthaldehydeYield 95%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

2-Bromo-6,7-dimethoxy-1-napthaldehyde (10). Dimethylformamide (3.0 g, 41 mmol) was added dropwise to solution of phosphorus tribromide (3.3 mL, 35 mmol) in dry chloroform (50 mL) at 0° C. The mixture was stirred at 0° C. for 1 h to give pale yellow suspension. A solution of compound 8 (2.0 g, 9.7 mmol) in chloroform was added to the yellow suspension and the mixture was heated at reflux for 1 h. The reaction mixture was cooled to 0° C. and saturated aqueous NaHCO3 solution was added dropwise until no effervescence was obtained. The resulting mixture was extracted with dichloromethane, dried (Na2SO4) and evaporated to provide the respective 2-bromo-3,4-dihydro-1-napthaldehyde derivatives as yellow solids. Each of the 2-bromo-3,4-dihydro-1-napthaldehyde derivatives were chromatographed on silica gel using a 3:1 mixture of hexanes:ethyl acetate as the eluent to give the 2-bromo-3,4-dihydro-1-napthaldehydes in an 87% yield. The 2-bromo-3,4-dihydro-1-napthaldehyde (2.4 g, 8.1 mmol) and DDQ (2.2 g, 97 mmol) was refluxed in toluene (50 mL) for 15 h. After cooling to room temperature, the mixture was subjected to filtration through a celite bed and the filtrate was evaporated to dryness. The residue obtained was chromatographed on 75 g silica gel using a 3:1 mixture of hexanes:ethyl acetate as eluent to give the 2-bromo-1-napthaldehyde in a 95% yield; 1H NMR δ 4.00 (3H, s), 4.05 (3H, s), 7.07 (1H, s), 7.54 (1H, d, J=8.5), 7.79 (1H, d, J=8.5), 8.71 (1H, s), 10.74 (1H, s); 13C NMR δ 56.3, 56.6, 104.2, 107.0, 126.5, 128.8, 129.4, 129.8, 129.9, 134.3, 150.4, 153.1, 195.9; HRMS calcd for C,3H11O3Br: 293.9891; found: 293.9896.

Workup

  1. customEach of the 2-bromo-3,4-dihydro-1-napthaldehyde derivatives were chromatographed on silica gel using
  2. additiona 3:1 mixture of hexanes
  3. customethyl acetate as the eluent to give the 2-bromo-3,4-dihydro-1-napthaldehydes in an 87% yield
  4. filtrationthe mixture was subjected to filtration through a celite bed
  5. customthe filtrate was evaporated to dryness
  6. customThe residue obtained
  7. customwas chromatographed on 75 g silica gel using
  8. additiona 3:1 mixture of hexanes

Sources & evidence

ORD record
ord-07eea244041f418a8ff34740f3ce3e78
Source dataset
uspto-grants-2000_10
Patent number
US06140328

Reaction notes

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