Isopropanol → 4,4,6-Trimethyl-1,2,3,4-tetrahydronaphthalen-1-one

HRID 915177Notes

Reaction equation

HRID 915177 reaction equation
[CH3:1][C:2]1([CH3:13])[C:11]2[C:6](=[CH:7][CH:8]=[C:9]([CH3:12])[CH:10]=2)[CH2:5][CH2:4][CH2:3]1.C([OH:17])(C)C>C(O)(=O)C.O.[O-2].[Cr+6].[O-2].[O-2]>[O:17]=[C:5]1[C:6]2[C:11](=[CH:10][C:9]([CH3:12])=[CH:8][CH:7]=2)[C:2]([CH3:13])([CH3:1])[CH2:3][CH2:4]1

Participants

6

Reactant 2

HCID 3776IsopropanolHCID 2263961,1,7-Trimethyl-1,2,3,4-tetrahydronaphthalene

Product 1

HCID 134632674,4,6-Trimethyl-1,2,3,4-tetrahydronaphthalen-1-one

Reagents, catalysts & solvents 3

HCID 10219390chromium (VI) trioxideCatalystHCID 176Acetic AcidSolvent2×HCID 962WaterSolvent

Procedure

A solution of chromium(VI)oxide (86 g, 0.861 mol) in acetic acid (400 mL) and water (40 mL) was added dropwise to a stirred solution of 1,1,7-trimethyl-1,2,3,4-tetrahydronaphthalene in acetic acid (70 mL) and the reaction mixture stirred 2.5 hours at room temperature. Isopropanol (5 mL) was added and the whole concentrated in vacuo. The residue was dissolved in hexane and filtered over celite. The organic was washed with water and brine, dried (Mg2SO4), filtered and evaporated to give 40.3 g of 1-oxo-4,4,6-trimethyl-1,2,3,4-tetrahydronaphthalene and used without further purification in the bromination (step e). 1H NMR (300 MHz; CDCl3): 1.36 (s, 6 H), 1.98 (t, J=6.9 Hz, 2 H), 2.38 (s, 3 H), 2.68 (t, J=6.9 Hz, 2 H), 7.01 (dd, J1=0.6 Hz, J2=7.9 Hz, 1 H), 7.19 (d, J=0.6 Hz, 1 H), 7.90 (d, J=8.1 Hz, 1 H).

Workup

  1. concentrationthe whole concentrated in vacuo
  2. dissolutionThe residue was dissolved in hexane
  3. filtrationfiltered over celite
  4. washThe organic was washed with water and brine
  5. dry with materialdried (Mg2SO4)
  6. filtrationfiltered
  7. customevaporated

Sources & evidence

ORD record
ord-11e0bfe9a35f4fc2ae2fb760a3fc6a06
Source dataset
uspto-grants-2007_09
Patent number
US07265139B2

Reaction notes

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