Trifluoromethanesulfonic acid → 3,6-dimethyl-3,4-dihydronaphthalen-1(2H)-one

HRID 926167Notes

Reaction equation

HRID 926167 reaction equation
[CH3:1][CH:2]([CH2:7][C:8]1[CH:9]=[C:10]([CH3:14])[CH:11]=[CH:12][CH:13]=1)[CH2:3][C:4]([OH:6])=O.OS(C(F)(F)F)(=O)=O>C(Cl)Cl>[CH3:1][CH:2]1[CH2:7][C:8]2[C:13](=[CH:12][CH:11]=[C:10]([CH3:14])[CH:9]=2)[C:4](=[O:6])[CH2:3]1

Participants

4

Reactant 2

HCID 62406Trifluoromethanesulfonic acidHCID 37508493-methyl-4-(3-methylphenyl)butanoic Acid

Product 1

HCID 671261793,6-dimethyl-3,4-dihydronaphthalen-1(2H)-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

3-Methyl-4-m-tolylbutanoic acid (20.6 g, 107 mmol, dissolved in 125 mL DCM) was added slowly to triflic acid (250 g, 1.7 mol) that was pre-cooled to 0° C. under an Ar atmosphere. After 30 minutes, the volume of the reaction is doubled with DCM and poured slowly onto 1.5 L crushed ice. The resulting icy slurry is allowed to stir and come to room temperature over 1 hour. The resulting aqueous layer was extracted with DCM and the combined organics dried over anhydrous MgSO4 and concentrated in vacuo. The procedure was repeated once and the two lots of crude product were combined and purified via elution on Isco silica gel column chromatography (0-15% EtOAc/hex) to afford 3,6-dimethyl-3,4-dihydronaphthalen-1(2H)-one. LCMS-ESI+ (m/z): [M+H]+ calcd for C12H15O: 175.3. found: 175.4.

Workup

  1. additionpoured slowly onto 1.5 L
  2. customcrushed ice
  3. waitcome to room temperature over 1 hour
  4. extractionThe resulting aqueous layer was extracted with DCM
  5. dry with materialthe combined organics dried over anhydrous MgSO4
  6. concentrationconcentrated in vacuo
  7. custompurified via elution on Isco silica gel column chromatography (0-15% EtOAc/hex)

Sources & evidence

ORD record
ord-3098963993f346a78b811cda590adf57
Source dataset
uspto-grants-2016_03
Patent number
US09284323B2

Reaction notes

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