Hydrochloric Acid → 7-Bromo-4H-1-benzopyran-4-one

HRID 1684870Notes

Reaction equation

HRID 1684870 reaction equation
Cl.[Br:2][C:3]1[CH:8]=[CH:7][C:6]([C:9](=[O:15])/[CH:10]=[CH:11]/N(C)C)=[C:5]([OH:16])[CH:4]=1>ClCCl>[Br:2][C:3]1[CH:4]=[C:5]2[C:6]([C:9](=[O:15])[CH:10]=[CH:11][O:16]2)=[CH:7][CH:8]=1

Participants

4

Reactant 2

HCID 313Hydrochloric AcidHCID 11737295HCID 11737295, compound

Product 1

HCID 186867527-Bromo-4H-1-benzopyran-4-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

Conc. HCl (100 mL) was added to a solution of (E)-1-(4-bromo-2-hydroxyphenyl)-3-(dimethylamino)prop-2-en-1-one (31.9 g, 118 mmol) in dichloromethane (900 mL) and the reaction mixture was heated at reflux 40 min with vigorous stirring. After being cooled to room temperature, the organic layer was separated and the aqueous layer was extracted with dichloromethane. The combined organic layers were washed with 3M potassium carbonate soln, water, and dried over Na2SO4. Filtration and concentration gave 7-bromo-4H-chromen-4-one as a pale yellow solid. LCMS 224.9 (M+H); 1H NMR (DMSO-d6) 8.29-8.31 (d, 1H), 7.92-7.99 (m, 2H), 7.64-7.66 (dd, 1H), 6.37-6.39 (d, 1H).

Workup

  1. temperaturethe reaction mixture was heated
  2. temperatureat reflux 40 min with vigorous stirring
  3. customthe organic layer was separated
  4. extractionthe aqueous layer was extracted with dichloromethane
  5. washThe combined organic layers were washed with 3M potassium carbonate soln
  6. dry with materialwater, and dried over Na2SO4
  7. filtrationFiltration and concentration

Sources & evidence

ORD record
ord-f2870eac1eec4cf2996070978292a3ea
Source dataset
uspto-grants-2012_04
Patent number
US08147818B2

Reaction notes

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