Sulfuric Acid → 1,1,3,3-Tetramethyl-2,3-dihydro-1H-indene

HRID 733323Notes

Reaction equation

HRID 733323 reaction equation
[CH3:1][C:2]([C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][CH:5]=1)=[CH2:3].[C:10](O)([CH3:13])([CH3:12])[CH3:11].S(=O)(=O)(O)O>C(O)(=O)C>[CH3:11][C:10]1([CH3:13])[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:2]([CH3:3])([CH3:1])[CH2:12]1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 6386tert-ButanolHCID 7407Alpha-Methylstyrene

Product 1

HCID 140266821,1,3,3-Tetramethyl-2,3-dihydro-1H-indeneYield 16.6%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Conditions

Temperature
40 °C

Procedure

A mixture of 117.26 g of α-Methylstyrene (Aldrich 99%, 0.98 mol) and 73.0 g of t-Butanol (Aldrich 99%, 0.97 mol) were slowly added (1 hour) to a mixture of 200 g of acetic acid and 200 g of sulfuric acid, previously warmed at 40° C. The suspension so-obtained was stirred 30 min at 40° C. and then the 2 layers were separated. The organic layer was washed with a 0.7 M NaOH acqueous solution (3×50 ml, neutrality) and water (2×50 ml). The opaque yellow solution obtained was then distilled at 26 mbar. At about 100° C. a colourless transparent liquid was distilled off (28.43 g), which was characterized by NMR as pure 1,1,3,3 tetramethylindane (16.6% yield).

Workup

  1. additionwere slowly added (1 hour)
  2. customThe suspension so-obtained
  3. customthe 2 layers were separated
  4. washThe organic layer was washed with a 0.7 M NaOH acqueous solution (3×50 ml, neutrality) and water (2×50 ml)
  5. customThe opaque yellow solution obtained
  6. distillationwas then distilled at 26 mbar
  7. distillationAt about 100° C. a colourless transparent liquid was distilled off (28.43 g), which

Sources & evidence

ORD record
ord-e4699e5822584eb0bc09ba364c00397c
Source dataset
uspto-grants-2009_09
Patent number
US07589160B2

Reaction notes

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