Sodium Hydroxide → 5-Bromo-7-ethyl-3-methyl-1-benzofuran

HRID 917532Notes

Reaction equation

HRID 917532 reaction equation
[Br:1][C:2]1[CH:12]=[CH:11][C:5]([O:6][CH2:7][C:8](=O)[CH3:9])=[C:4]([CH2:13][CH3:14])[CH:3]=1.[OH-].[Na+]>CCCCCC>[Br:1][C:2]1[CH:3]=[C:4]([CH2:13][CH3:14])[C:5]2[O:6][CH:7]=[C:8]([CH3:9])[C:11]=2[CH:12]=1

Participants

4

Reactant 2

HCID 14798Sodium HydroxideHCID 58963157HCID 58963157, compound

Product 1

HCID 589631565-Bromo-7-ethyl-3-methyl-1-benzofuranYield 78.1%

Reagents, catalysts & solvents 1

HCID 8058HexaneSolvent

Procedure

A stirred solution of polyphosphoric acid (461 ml) was heated to 95° C., and 1-(4-bromo-2-ethylphenoxy)propan-2-one 30 (93 gm) was added portionwise. The reaction was stirred 1 hour. The reaction was determined to be complete and the contents poured onto 1:1 hexane; 10% aqeous sodium hydroxide (2 liters). A strong exotherm was noted. The organic layer was separated and washed twice with 1 N Na2S2O3. The organic layer was then stirred with charcoal and anhydrous magnesium sulfate for 30 minutes. The reaction was filtered through celite and the solvent removed in vacuo. The crude product was run through a plug of silica gel (375 g) and eluted with hexanes. The solvent was removed in vacuo to yield 67.58 g of 5-bromo-7-ethyl-3-methylbenzofuran 31.

Workup

  1. customThe organic layer was separated
  2. washwashed twice with 1 N Na2S2O3
  3. stirringThe organic layer was then stirred with charcoal and anhydrous magnesium sulfate for 30 minutes
  4. filtrationThe reaction was filtered through celite
  5. customthe solvent removed in vacuo
  6. washeluted with hexanes
  7. customThe solvent was removed in vacuo

Sources & evidence

ORD record
ord-353d940f4a6b44729fd3bccbe37f47a1
Source dataset
uspto-grants-2007_09
Patent number
US07273886B2

Reaction notes

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