Benzenepropanal → 2,3-dihydro-6-fluoro-2-(2-phenylethyl)-4H-1-benzopyran-4-one

HRID 487212Notes

Reaction equation

HRID 487212 reaction equation
N1CCCC1.[OH:6][C:7]1[CH:12]=[CH:11][C:10]([F:13])=[CH:9][C:8]=1[C:14](=[O:16])[CH3:15].[C:17]1([CH2:23][CH2:24][CH:25]=O)[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>C1(C)C=CC=CC=1.C(OCC)(=O)C>[F:13][C:10]1[CH:11]=[CH:12][C:7]2[O:6][CH:25]([CH2:24][CH2:23][C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)[CH2:15][C:14](=[O:16])[C:8]=2[CH:9]=1

Participants

6

Reactant 3

HCID 7707BenzenepropanalHCID 31268PyrrolidineHCID 959922-Acetyl-4-fluorophenol

Product 1

HCID 190944442,3-dihydro-6-fluoro-2-(2-phenylethyl)-4H-1-benzopyran-4-one

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Procedure

Pyrrolidine (2.4 mL) was added to a solution of 2'-hydroxy-5'-fluoroacetophenone (15.1 g) and 3-phenylpropanal (13.2 mL) in toluene (30 mL), and the mixture heated under reflux in a Dean-Stark apparatus for 3 hours, cooled, diluted with ethyl acetate and washed with aqueous 1N HCl, aqueous 1N NaOH, H2O, brine, dried (Na2SO4), filtered and evaporated, and the residue purified by column chromatography (6:1 hexane/diethyl ether, SiO2) to yield 2,3-dihydro-6-fluoro-2-(2-phenylethyl)-4H-1-benzopyran-4-one (18 gm, Rf=0.3 4:1 hexane/diethyl ether).

Workup

  1. temperaturethe mixture heated
  2. temperatureunder reflux in a Dean-Stark apparatus for 3 hours
  3. temperaturecooled
  4. washwashed with aqueous 1N HCl, aqueous 1N NaOH, H2O, brine
  5. dry with materialdried (Na2SO4)
  6. filtrationfiltered
  7. customevaporated
  8. customthe residue purified by column chromatography (6:1 hexane/diethyl ether, SiO2)

Sources & evidence

ORD record
ord-28c86a189a1d4058a519c5c5a726a985
Source dataset
uspto-grants-1994_03
Patent number
US05294635

Reaction notes

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