4-Bromobenzaldehyde → 1-Bromo-4-(2-methylprop-1-en-1-yl)benzene

HRID 129798Notes

Reaction equation

HRID 129798 reaction equation
[I-].[CH:2]([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)([CH3:4])[CH3:3].CC(C)([O-])C.[K+].[Br:30][C:31]1[CH:38]=[CH:37][C:34]([CH:35]=O)=[CH:33][CH:32]=1>C1COCC1.C1OCCOCCOCCOCCOCCOC1>[Br:30][C:31]1[CH:38]=[CH:37][C:34]([CH:35]=[C:2]([CH3:4])[CH3:3])=[CH:33][CH:32]=1

Participants

6

Reactant 3

HCID 707414-BromobenzaldehydeHCID 2723783Isopropyltriphenylphosphonium iodideHCID 23665647Potassium tert-butoxide

Product 1

HCID 130990411-Bromo-4-(2-methylprop-1-en-1-yl)benzeneYield 77%

Reagents, catalysts & solvents 2

HCID 2855718-Crown-6CatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

To a stirred slurry of 17.29 g (40.0 mmol) of isopropyltriphenylphosphonium iodide and 500 mg (2 mmol) of 18-crown-6 in 100 mL of THF under nitrogen at 5° C. was added 4.50 g (40.0 mmol) of potassium t-butoxide over 5 min. the resulting deep red-orange slurry was stirred 10 min and then a solution of 6.50 g (35.0 mmol) 4-bromobenzaldehyde in 40 mL of THF was added at a rate to keep the temperature below +10° C. The resulting bright yellow slurry was stirred for 20 min and then poured into 300 mL of hexanes. The solids were filtered off and the filtrate evaporated. This residue was purified by flash chromatography (5×15 cm column) and eluted with hexanes to provide 5.66 g (77%) of title bromide as a colorless oil.

Workup

  1. customthe temperature below +10° C
  2. stirringThe resulting bright yellow slurry was stirred for 20 min
  3. filtrationThe solids were filtered off
  4. customthe filtrate evaporated
  5. customThis residue was purified by flash chromatography (5×15 cm column)
  6. washeluted with hexanes

Sources & evidence

ORD record
ord-33cb6b5b09ce434795bb1cc159dd7518
Source dataset
uspto-grants-1995_11
Patent number
US05470845

Reaction notes

Loading…