Hydrochloric Acid → 2-Ethyl-6-fluoro-3-phenyl-4H-chromen-4-one

HRID 239622Notes

Reaction equation

HRID 239622 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]([OH:17])=[C:6]([C:8](=[O:16])[CH2:9][C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=2)[CH:7]=1.[C:18](OC(=O)CC)(=O)[CH2:19][CH3:20].Cl>C(N(CC)CC)C>[CH2:19]([C:20]1[O:17][C:5]2[C:6]([C:8](=[O:16])[C:9]=1[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)=[CH:7][C:2]([F:1])=[CH:3][CH:4]=2)[CH3:18]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 31263Propionic anhydrideHCID 27785851-(5-Fluoro-2-hydroxyphenyl)-2-phenylethanone

Product 1

HCID 602090512-Ethyl-6-fluoro-3-phenyl-4H-chromen-4-oneYield 65%

Reagents, catalysts & solvents 1

HCID 8471TriethylamineSolvent

Procedure

Intermediate 50 (3.0 g, 13.63 mmoles) was taken in a RB flask and to this triethylamine (30 ml) and propionic anhydride (5.30 g, 40.78 mmoles) were added and the mixture was refluxed for 24 h. After cooling to RT, the reaction mixture was acidified by the addition of 1N HCl solution, extracted with ethyl acetate, washed with sodium bicarbonate solution, dried with sodium sulphate and concentrated. The crude product was purified by column chromatography with ethyl acetate: petroleum ether to afford the title compound as off-white solid (2.27 g, 65% yield). 1H-NMR (δ ppm, DMSO-d6, 400 MHz): δ 7.79(dd, J=7.1, 4.4 Hz, 1H), 7.73(dt, J=7.7,3.1 Hz, 2H), 7.46(t, J=8.2 Hz, 2H), 7.40(m, 1H), 7.27 (dd, J=8.2,1.4 Hz, 2H), 2.55(q, J=7.5 Hz, 2H), 1.19(t, J=7.6 Hz, 3H).

Workup

  1. additionwere added
  2. temperaturethe mixture was refluxed for 24 h
  3. extractionextracted with ethyl acetate
  4. washwashed with sodium bicarbonate solution
  5. dry with materialdried with sodium sulphate
  6. concentrationconcentrated
  7. customThe crude product was purified by column chromatography with ethyl acetate

Sources & evidence

ORD record
ord-93ae20624df442f5a10303e83c5d042b
Source dataset
uspto-grants-2014_02
Patent number
US08642607B2

Reaction notes

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