Pyridiniumtribromide → 9-bromo-3-(2-bromoacetyl)-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one

HRID 2172513Notes

Reaction equation

HRID 2172513 reaction equation
[C:1]([C:4]1[CH:5]=[CH:6][C:7]2[C:16]3[CH:15]=[C:14]4[CH2:17][CH2:18][CH2:19][C:20](=[O:21])[C:13]4=[CH:12][C:11]=3[O:10][CH2:9][C:8]=2[CH:22]=1)(=[O:3])[CH3:2].C(Cl)Cl.CO.[Br-:28].[Br-:29].[Br-].[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1.[NH+]1C=CC=CC=1>CCOC(C)=O>[Br:28][CH:19]1[CH2:18][CH2:17][C:14]2=[CH:15][C:16]3[C:7]4[CH:6]=[CH:5][C:4]([C:1](=[O:3])[CH2:2][Br:29])=[CH:22][C:8]=4[CH2:9][O:10][C:11]=3[CH:12]=[C:13]2[C:20]1=[O:21]

Participants

5

Reactant 3

HCID 21124087PyridiniumtribromideHCID 21226129Dichloromethane methanolHCID 866883753-acetyl-10,11-dihydro-5H-dibenzo(c,g)chromen-8(9H)-one

Product 1

HCID 866883729-bromo-3-(2-bromoacetyl)-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
35 °C

Procedure

A 20 mL vial with a stir bar was charged with 3-acetyl-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one (100 mg, 0.366 mmol), 9:1 CH2Cl2/MeOH (3.4 mL) and pyridinium tribromide (246 mg, 0.769 mmol). The solution was heated to 35° C. After 30 minutes, the reaction was judged complete. The mixture was cooled to ambient temperature, diluted with EtOAc (50 mL) and sequentially washed with saturated aqueous Na2S2O3 (20 mL), 2% aqueous NaHCO3 (20 mL), water (20 mL), and brine (10 mL). The organic phase was dried over MgSO4, filtered and concentrated under reduced pressure resulting in 9-bromo-3-(2-bromoacetyl)-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one (68 mg, 41%): 400 MHz 1H NMR (CDCl3) δ 8.03-8.01 (m, 1H), 7.85 (d, J=8.2 Hz, 1H), 7.82 (s, 1H), 7.71 (s, 1H), 7.67 (s, 1H), 5.19 (s, 2H), 4.74 (dd, J=4.1, 4.1 Hz, 1H), 4.45 (s, 2H), 3.37-3.29 (m, 1H), 2.99-2.92 (m, 1H), 2.59-2.46 (m, 2H).

Workup

  1. temperatureThe mixture was cooled to ambient temperature
  2. washsequentially washed with saturated aqueous Na2S2O3 (20 mL), 2% aqueous NaHCO3 (20 mL), water (20 mL), and brine (10 mL)
  3. dry with materialThe organic phase was dried over MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated under reduced pressure
  6. customresulting in 9-bromo-3-(2-bromoacetyl)-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one (68 mg, 41%)

Sources & evidence

ORD record
ord-dca29b41dfad4f50ab3e5f1c402b01e3
Source dataset
uspto-grants-2015_06
Patent number
US09051340B2

Reaction notes

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