Aluminum(III) Chloride → 2-Methyl-2,3-dihydro-1H-cyclopenta[a]naphthalen-1-one

HRID 1266680Notes

Reaction equation

HRID 1266680 reaction equation
[Cl-].[Al+3].[Cl-].[Cl-].Cl[C:6]([CH3:20])([CH3:19])[C:7]([C:9]1[C:18]2[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=2)[CH:12]=[CH:11][CH:10]=1)=[O:8]>ClCCl.CCCCCCC>[CH3:19][CH:6]1[C:7](=[O:8])[C:9]2[C:18]3[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=3[CH:12]=[CH:11][C:10]=2[CH2:20]1

Participants

5

Reactant 2

HCID 6451240Aluminum(III) ChlorideHCID 18551888HCID 18551888, compound

Product 1

HCID 108780732-Methyl-2,3-dihydro-1H-cyclopenta[a]naphthalen-1-oneYield 75%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 8900HeptaneSolvent

Procedure

Aluminium chloride (35 g, 0.26 mole) was suspended in 200 ml of anhydrous dichioromethane. 2-Chloro-2-methyl-1-(1-naphthalenyl)-1-propanone (30.0 g, 0.13 mole) in 30 ml of heptane was slowly added to this suspension. During the addition (30 min) the temperature was kept at room temperature. After the addition was completed, the reaction mixture was stirred for 1 h at room temperature. The reaction mixture was poured onto 400 g of ice water, and the organic layer was separated. The organic layer was successively washed twice with a 5 wt % aqueous hydrochloric acid solution (150 ml) and once with a 2 wt % aqueous sodium bicarbonate solution (150 ml). After drying over anhydrous magnesium sulfate the solution was concentrated under reduced pressure. The yield of crude 2,3-dihydro-2-methyl-1H-benz[e]inden-1-one was 23.4 g or 93%. Distillation of the crude product under reduced pressure (b.p. 130° C., 0.5 mbar) gave 18.7 g (75%) of 2,3-dihydro-2-methyl-1H-benz[e]inden-1-one, which crystallized upon standing at room temperature.

Workup

  1. additionDuring the addition (30 min) the temperature
  2. customwas kept at room temperature
  3. additionAfter the addition
  4. customthe organic layer was separated
  5. washThe organic layer was successively washed twice with a 5 wt % aqueous hydrochloric acid solution (150 ml) and once with a 2 wt % aqueous sodium bicarbonate solution (150 ml)
  6. dry with materialAfter drying over anhydrous magnesium sulfate the solution
  7. concentrationwas concentrated under reduced pressure
  8. distillationDistillation of the crude product under reduced pressure (b.p. 130° C., 0.5 mbar)

Sources & evidence

ORD record
ord-dfda88b497ea4db58ab5cafa54106fba
Source dataset
uspto-grants-2003_04
Patent number
US06548710B2

Reaction notes

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