Hydrogen Bromide → 2,4,7-trimethyl-1-indanone

HRID 2425308Notes

Reaction equation

HRID 2425308 reaction equation
[CH3:1][C:2]1[CH:3]=[CH:4][C:5]([CH3:8])=[CH:6][CH:7]=1.[Al+3].[Cl-].[Cl-].[Cl-].Br[C:14]([CH3:19])([CH3:18])[C:15](Br)=[O:16].Br.Cl>ClC1C=CC=CC=1>[CH3:18][CH:14]1[CH2:19][C:4]2[C:3](=[C:2]([CH3:1])[CH:7]=[CH:6][C:5]=2[CH3:8])[C:15]1=[O:16]

Participants

7

Reactant 5

HCID 260Hydrogen BromideHCID 313Hydrochloric AcidHCID 7809P-XyleneHCID 886852-Bromo-2-methylpropionyl bromideHCID 6451240Aluminum(III) Chloride

Product 1

HCID 110951212,4,7-trimethyl-1-indanoneYield 98%

Reagents, catalysts & solvents 1

HCID 7964ChlorobenzeneSolvent

Conditions

Temperature
0 °C

Procedure

6.66 g of p-xylene (62.10 mmol) were added at room temperature to a suspension of 10.51 g of AlCl3 (78.0 mmol) in 40 ml of chlorobenzene under nitrogen; the so obtained yellow suspension was cooled to 0° C. and 6.50 ml of 2-bromoisobutyrylbromide (52.6 mmol, AlCl3/p-xylene/2-bromoisobutyrylbromide=1.5/1.2/1.0) were added dropwise in about 2 min. The flask is connected to a water trap in which the produced HBr gas is neutralized with a base. At the end of the addition, the solution was allowed to reach ambient temperature. The so obtained red solution was stirred for 2 h. The reaction mixture was transferred into a flask containing 30 g of ice and 10 ml of 37% HCl, stirred for 15 min, then the organic layer was separated, and the aqueous layer washed with Et2O (2×100 ml). The combined organic layers were washed with a saturated solution of NaHCO3 in water, then with H2O. The solution was dried over Na2SO4 and then all volatiles were removed in vacuo to leave a slightly yellow oil (8.95 g, yield 98%).

Workup

  1. customThe flask is connected to a water trap in which
  2. additionAt the end of the addition
  3. customto reach ambient temperature
  4. customThe so obtained red solution
  5. customThe reaction mixture was transferred into a flask
  6. stirringstirred for 15 min
  7. customthe organic layer was separated
  8. washthe aqueous layer washed with Et2O (2×100 ml)
  9. washThe combined organic layers were washed with a saturated solution of NaHCO3 in water
  10. dry with materialThe solution was dried over Na2SO4
  11. customall volatiles were removed in vacuo

Sources & evidence

ORD record
ord-cbb479e35cd7421f803a8c4b33e5753f
Source dataset
uspto-grants-2011_06
Patent number
US07964679B2

Reaction notes

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