O-Xylene → 2,5,6-Trimethyl-2,3-dihydro-1H-inden-1-one

HRID 1047473Notes

Reaction equation

HRID 1047473 reaction equation
[Al+3].[Cl-].[Cl-].[Cl-].Br[C:6]([CH3:11])([CH3:10])[C:7](Br)=[O:8].[CH3:12][C:13]1[CH:14]=[CH:15][CH:16]=[CH:17][C:18]=1[CH3:19]>C(Cl)Cl>[CH3:10][CH:6]1[CH2:11][C:16]2[C:15](=[CH:14][C:13]([CH3:12])=[C:18]([CH3:19])[CH:17]=2)[C:7]1=[O:8]

Participants

5

Reactant 3

HCID 7237O-XyleneHCID 886852-Bromo-2-methylpropionyl bromideHCID 6451240Aluminum(III) Chloride

Product 1

HCID 183147572,5,6-Trimethyl-2,3-dihydro-1H-inden-1-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
0 °C

Procedure

To a suspension of 557 g (4.2 mol) AlCl3 in 500 ml of CH2Cl2 362 g (1.58 mol) of 2-bromo-2-methylpropanoyl bromide was added dropwise with vigorous stirring over 15 min at 0° C. This mixture was stirred for 45 min at this temperature; then, a solution of 167 g (1.58 mol) of o-xylene in 200 ml of CH2Cl2 was added dropwise. The mixture was slowly warmed to ambient temperature, stirred additionally overnight, and then poured onto 2000 cm3 of ice. The organic layer was separated, and the aqueous layer was extracted with 3×500 ml of CH2Cl2. The combined extract was dried over MgSO4 and evaporated to dryness. Fractional distillation gave a yellowish mixture of the title indanones, b.p. 143-148° C./7 mm Hg. This mixture was recrystallized from 800 ml of n-hexane. Crystals of 2,5,6-trimethylindan-1-one precipitated at −30° C. were filtered off, washed with 2×40 ml of cold n-hexane, and dried in vacuum. Yield 57.8 g (21%) of 2,5,6-trimethylindan-1-one.

Workup

  1. additionwas added dropwise
  2. stirringThis mixture was stirred for 45 min at this temperature
  3. temperatureThe mixture was slowly warmed to ambient temperature
  4. stirringstirred additionally overnight
  5. customThe organic layer was separated
  6. extractionthe aqueous layer was extracted with 3×500 ml of CH2Cl2
  7. extractionThe combined extract
  8. dry with materialwas dried over MgSO4
  9. customevaporated to dryness
  10. distillationFractional distillation
  11. customgave
  12. customThis mixture was recrystallized from 800 ml of n-hexane
  13. customCrystals of 2,5,6-trimethylindan-1-one precipitated at −30° C.
  14. filtrationwere filtered off
  15. washwashed with 2×40 ml of cold n-hexane
  16. customdried in vacuum

Sources & evidence

ORD record
ord-ee4ad3ecacf6470e98ec92b986310509
Source dataset
uspto-grants-2013_10
Patent number
US08569532B2

Reaction notes

Loading…