5-Methylene-10,11-dihydro-5H-dibenzo[a,d][7]annulene → 5-bromomethylene-10,11-dihydro-5H-dibenzo[a,d]cycloheptene

HRID 2218681Notes

Reaction equation

HRID 2218681 reaction equation
[CH2:1]=[C:2]1[C:8]2[CH:9]=[CH:10][CH:11]=[CH:12][C:7]=2[CH2:6][CH2:5][C:4]2[CH:13]=[CH:14][CH:15]=[CH:16][C:3]1=2.[Br-:17].[Br-].[Br-].CN(C)C1C=C[NH+]=CC=1.CN(C1C=C[NH+]=CC=1)C.CN(C1C=C[NH+]=CC=1)C>C(Cl)(Cl)Cl>[Br:17][CH:1]=[C:2]1[C:3]2[CH:16]=[CH:15][CH:14]=[CH:13][C:4]=2[CH2:5][CH2:6][C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][C:8]1=2

Participants

4

Reactant 2

HCID 46413975-Methylene-10,11-dihydro-5H-dibenzo[a,d][7]annuleneHCID 666746234-Dimethylaminopyridinium tribromide

Product 1

HCID 52579405-bromomethylene-10,11-dihydro-5H-dibenzo[a,d]cyclohepteneYield 94.1%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

Dissolve 5-methylene-10,11-dihydro-5H-dibenzo[a,d]cycloheptene (10.00 g, 48.48 mmol) in CHCl3 (125 mL) and add 4-(dimethylamino)pyridinium tribromide (19.35 g, 53.32 mmol). Stir at room temperature for 2.5 h and quench with saturated aqueous Na2SO3. Separate layers, wash organics with saturated aqueous NaHCO3, then H2O. The dried organics (MgSO4) and concentrated to a yellow oil. Purify crude product by loading onto a 20 g plug of silica gel and eluting with hexanes until eluent shows no UV activity. Combine and concentrate hexane washes to afford 13.01 g (94%) of the title compound as a white solid, mp 73.6° C. HPLC shows 99% purity.

Workup

  1. customquench with saturated aqueous Na2SO3
  2. washSeparate layers, wash organics with saturated aqueous NaHCO3
  3. concentrationThe dried organics (MgSO4) and concentrated to a yellow oil
  4. customPurify crude product
  5. washeluting with hexanes until eluent shows no UV activity
  6. concentrationCombine and concentrate hexane washes

Sources & evidence

ORD record
ord-347ca9f236c346fdadaac528d99e19a8
Source dataset
uspto-grants-2008_08
Patent number
US07411072B2

Reaction notes

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