Bromine → 1,1,3,4,4,6-Hexamethyl-7-bromacetyl-1,2,3,4-tetrahydronaphthalene

HRID 1579075Notes

Reaction equation

HRID 1579075 reaction equation
[CH3:1][C:2]1([CH3:19])[C:11]2[C:6](=[CH:7][C:8]([CH3:15])=[C:9]([C:12](=[O:14])[CH3:13])[CH:10]=2)[C:5]([CH3:17])([CH3:16])[CH:4]([CH3:18])[CH2:3]1.[Br:20]Br>C(O)(=O)C>[CH3:1][C:2]1([CH3:19])[C:11]2[C:6](=[CH:7][C:8]([CH3:15])=[C:9]([C:12](=[O:14])[CH2:13][Br:20])[CH:10]=2)[C:5]([CH3:17])([CH3:16])[CH:4]([CH3:18])[CH2:3]1

Participants

4

Reactant 2

HCID 24408BromineHCID 89440Tonalide

Product 1

HCID 214306251,1,3,4,4,6-Hexamethyl-7-bromacetyl-1,2,3,4-tetrahydronaphthaleneYield 38%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

1,1,3,4,4,6-Hexamethyl-7-acetyl-1,2,3,4-tetrahydronaphthalene (33 gm,0.12 m) was dissolved in glacial acetic acid (40 ml.) and the solution treated portionwise with bromine (20.3 gm) with stirring. The mixture was allowed to stand overnight at room temperature and poured onto ice (100 gm.). The resulting mixture was extracted with ether (3 ×100 ml.) and the combined extracts washed with saturated sodium carbonate (2 × 50 ml.) and then brine. The washed extracts were then dried (MgSO4) and the solvent removed in vacuo to give a crystalline solid. This was recrystallised from absolute ethanol to give 1,1,3,4,4,6-hexamethyl-7-bromoacetyl-1,2,3,4-tetrahydronaphthalene as colourless needles (16 gm, 38%) m.p. 68°C. [Found: C, 64.40; H, 7.65%. C18H25BrO requires: C,64.09; H,7.47%].

Workup

  1. additionpoured onto ice (100 gm.)
  2. extractionThe resulting mixture was extracted with ether (3 ×100 ml.)
  3. washthe combined extracts washed with saturated sodium carbonate (2 × 50 ml.)
  4. dry with materialThe washed extracts were then dried (MgSO4)
  5. customthe solvent removed in vacuo
  6. customto give a crystalline solid
  7. customThis was recrystallised from absolute ethanol

Sources & evidence

ORD record
ord-4f836ff607a94dd1952b1bc909ba4724
Source dataset
uspto-grants-1976_02
Patent number
US03940443

Reaction notes

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