N-bromobutanimide → 2,8-dimethyl-5H-dibenzo[a,d][7]annulen-5-one

HRID 1275901Notes

Reaction equation

HRID 1275901 reaction equation
[CH3:1][C:2]1[CH:18]=[CH:17][C:5]2[C:6](=[O:16])[C:7]3[CH:14]=[CH:13][C:12]([CH3:15])=[CH:11][C:8]=3[CH2:9][CH2:10][C:4]=2[CH:3]=1.BrN1C(=O)CCC1=O>C(OCC)(=O)C>[CH3:1][C:2]1[CH:18]=[CH:17][C:5]2[C:6](=[O:16])[C:7]3[CH:14]=[CH:13][C:12]([CH3:15])=[CH:11][C:8]=3[CH:9]=[CH:10][C:4]=2[CH:3]=1

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 2211720110,11-dihydro-2,8-dimethyl-5H-dibenzo[a,d]cyclohepten-5-one

Product 1

HCID 221172592,8-dimethyl-5H-dibenzo[a,d][7]annulen-5-one

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

10,11-Dihydro-2,8-dimethyl-5H-dibenzo[a,d]cyclohepten-5-one (European Patent, 1993, 0 25 589 322 A1) (6 g) and N-bromosuccinimide (5 g) in ethyl acetate (100 ml) was irradiated with a 500 W halogen lamp. After 5 hours the reaction mixture was cooled and quenched with brine. The organic layer was collected, dried (MgSO4) and evaporated under reduced pressure. The residue was dissolved in dry dimethylformamide, treated with 1,5-diazabicyclo[4.3.0]non-5-ene (3.5 ml) and heated at 80° C. for 0.25 hours. The cooled reaction mixture was washed with 2M HCl, brine, dried (MgSO4) and evaporated under reduced pressure. Purification was by chromatography eluting with toluene. Yield 4.5 g.

Workup

  1. temperatureAfter 5 hours the reaction mixture was cooled
  2. customquenched with brine
  3. customThe organic layer was collected
  4. dry with materialdried (MgSO4)
  5. customevaporated under reduced pressure
  6. dissolutionThe residue was dissolved in dry dimethylformamide
  7. additiontreated with 1,5-diazabicyclo[4.3.0]non-5-ene (3.5 ml)
  8. customThe cooled reaction mixture
  9. washwas washed with 2M HCl, brine
  10. dry with materialdried (MgSO4)
  11. customevaporated under reduced pressure
  12. customPurification
  13. washeluting with toluene

Sources & evidence

ORD record
ord-458b634a76da4bd4b11ba3c01f990cd4
Source dataset
uspto-grants-2000_12
Patent number
US06162808

Reaction notes

Loading…