Pentanal → 1-(3,5-Difluorophenyl)pentan-1-ol

HRID 327370Notes

Reaction equation

HRID 327370 reaction equation
[CH:1](=[O:6])[CH2:2][CH2:3][CH2:4][CH3:5].Br[C:8]1[CH:13]=[C:12]([F:14])[CH:11]=[C:10]([F:15])[CH:9]=1.[Mg].[Cl-].[NH4+]>CCOCC.C1COCC1>[F:14][C:12]1[CH:13]=[C:8]([CH:1]([OH:6])[CH2:2][CH2:3][CH2:4][CH3:5])[CH:9]=[C:10]([F:15])[CH:11]=1

Participants

7

Reactant 4

HCID 8063PentanalHCID 25517Ammonium ChlorideHCID 1363131-Bromo-3,5-difluorobenzeneHCID 5462224Magnesium

Product 1

HCID 225984431-(3,5-Difluorophenyl)pentan-1-olYield 116%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of pentanal (19.0 g, 0.22 mol) in dry ether (75 ml) is added dropwise to a stirred solution of the Grignard reagent at room temperature, under dry nitrogen, prepared from 1-bromo-3,5-difluoro-benzene (50.2 g, 0.26 mol) and magnesium (7.25 g, 0.30 mol) in dry THF (100 ml). The stirred mixture is heated under reflux for 2 h, cooled and a saturated solution of ammonium chloride (300 ml) is added. The product is extracted into ether (twice), and the combined ethereal extracts are washed with water and dried (MgSO4). The solvent is removed in vacuo to give a pale-orange liquid (51.1 g) which is distilled to yield a colourless liquid. Smaller quantities of crude product are purified by column chromatography (silica gel/dichloromethane) to yield a colourless liquid, bp 90° C. at 0.5 mm Hg.

Workup

  1. temperatureThe stirred mixture is heated
  2. temperatureunder reflux for 2 h
  3. temperaturecooled
  4. extractionThe product is extracted into ether (twice), and the combined ethereal extracts
  5. washare washed with water
  6. dry with materialdried (MgSO4)
  7. customThe solvent is removed in vacuo

Sources & evidence

ORD record
ord-076640e60e0f4a54abc6f912cc20b302
Source dataset
uspto-grants-1993_12
Patent number
US05273680

Reaction notes

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