Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → (2S)-2',4'-difluoro-2-hydroxypropiophenone

HRID 1654189Notes

Reaction equation

[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[C:9](=[O:19])[C@@H:10]([O:12]C1CCCCO1)[CH3:11].C1(C)C=CC(S([O-])(=O)=O)=CC=1.[NH+]1C=CC=CC=1>C(O)C>[F:1][C:2]1[CH:7]=[C:6]([F:8])[CH:5]=[CH:4][C:3]=1[C:9](=[O:19])[C@@H:10]([OH:12])[CH3:11]

Participants

Conditions

Temperature: 55 °C

Procedure

In ethanol (3 ml) was dissolved (2S)-2',4'-difluoro-2-(3,4,5,6-tetrahydro-2H-pyran-2-yloxy)propiophenone (95 mg), to which was added pyridinium p-toluenesulfonate (21 mg), followed by stirring for one hour at 55° C. The solvent was distilled off under reduced pressure, and the residue was dissolved in ethyl acetate (20 ml), which was dried over anhydrous magnesium sulfate, followed by distilling off the solvent. The residue was purified by means of a silica gel chromatography (eluent, hexane:ethyl acetate=5:1) to give (2S)-2',4'-difluoro-2-hydroxypropiophenone (40 mg) as a pale yellow oily product.

Workup

distillationThe solvent was distilled off under reduced pressure
dissolutionthe residue was dissolved in ethyl acetate (20 ml)
dry with materialwhich was dried over anhydrous magnesium sulfate
distillationby distilling off the solvent
customThe residue was purified by means of a silica gel chromatography (eluent, hexane:ethyl acetate=5:1)

Sources & evidence

ORD record: ord-1fa21ef0d7f04c5c80985eaf1f3cca82
Source dataset: uspto-grants-1995_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05405861

Reaction notes

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