4-Chlorobenzaldehyde → 1-(4-Chloro-phenyl)-2-methyl-but-3-en-1-ol

HRID 964732Notes

Reaction equation

HRID 964732 reaction equation
[CH2:1](Cl)[CH:2]=[CH:3][CH3:4].[Mg].[Cl:7][C:8]1[CH:15]=[CH:14][C:11]([CH:12]=[O:13])=[CH:10][CH:9]=1>O1CCCC1>[CH3:4][CH:3]([CH:12]([C:11]1[CH:14]=[CH:15][C:8]([Cl:7])=[CH:9][CH:10]=1)[OH:13])[CH:2]=[CH2:1]

Participants

5

Reactant 3

HCID 77264-ChlorobenzaldehydeHCID 11589Crotyl chlorideHCID 5462224Magnesium

Product 1

HCID 113676051-(4-Chloro-phenyl)-2-methyl-but-3-en-1-olYield 70.5%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Conditions

Temperature
0 °C

Procedure

Crotyl chloride (154.7 g, 1.71 mol) in dry tetrahydrofuran (530 ml) was added to magnesium turnings (46.0 g, 1.89 mol) in dry tetrahydrofuran (130 ml) at such a rate so as to maintain steady reflux. After addition was complete the mixture was heated under reflux for a further hour and then cooled to 0° C. 4-Chlorobenzaldehyde (120.0 g, 0.854 mol) in dry tetrahydrofuran (780 ml) was added over a period of 2 hours. After a further hour the solution was decanted from the excess magnesium into saturated aqueous ammonium chloride solution and the magnesium washed with ether. 2M Hydrochloric acid was added to dissolve the precipitate and the mixture extracted with ether. The combined extracts were washed with water, dried and evaporated in vacuo. Partial purification was achieved by chromatography [SiO2, hexane-ethyl acetate mixtures] to give 3-methyl-4-(4-chlorophenyl)-but-1-en-4-ol (118.45 g, approximately 90% pure, approximately 64%).

Workup

  1. temperatureto maintain steady reflux
  2. additionAfter addition
  3. temperaturewas heated
  4. temperatureunder reflux for a further hour
  5. customAfter a further hour the solution was decanted from the excess magnesium into saturated aqueous ammonium chloride solution
  6. washthe magnesium washed with ether
  7. addition2M Hydrochloric acid was added
  8. dissolutionto dissolve the precipitate
  9. extractionthe mixture extracted with ether
  10. washThe combined extracts were washed with water
  11. customdried
  12. customevaporated in vacuo
  13. customPartial purification

Sources & evidence

ORD record
ord-dc85be50b81743c5b246b98903cca06a
Source dataset
uspto-grants-1998_06
Patent number
US05770741

Reaction notes

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