Reaktion #93503

Reaktionsgleichung

potassium tert.-butoxide

ammonium chloride

bromomethyltriphenylphosphonium bromide

potassium tert.-butoxide

p-chlorobenzaldehyde

→

title compound

1-Chloro-4-ethynylbenzene

Lösungsmittel

H2O

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeto cold reaction mixture
2. 2
   workup.STIRRINGstir for 30 minutes
3. 3
   Temperaturto warm to room temperature
4. 4
   workup.WAITAfter 18 hours
5. 5
   Extraktionextract with 500 ml diethyl ether
6. 6
   TrocknenWash organic layer with 2×400 ml saturated aqueous sodium chloride solution, dry over magnesium sulfate
7. 7
   Filtrationfilter
8. 8
   Sonstigeevaporate solvent to dryness
9. 9
   FiltrationWash residue with 200 ml hexane and filter off precipitate
10. 10
    workup.DISSOLUTIONEvaporate hexane and dissolve material in 150 ml hexane methylene chloride (66:33) solution
11. 11
    Waschenelute through column
12. 12
    workup.ADDITIONcontaining 300 g silica gel (Merck 60-230 mesh) with hexane: methylene chloride (66:33) solution
13. 13
    SonstigeCollect desired fraction
14. 14
    Sonstigeevaporate solvent
15. 15
    workup.DISTILLATIONDistill residue in vacuo and collect fraction boiling at 65° C. (8.5 mmHg)

Vorschrift

Dissolve 276.5 g (0.634 mole) of bromomethyltriphenylphosphonium bromide in 1800 ml THF and cool to -78° C. Add 67.6 g (0.062 mole) potassium tert.-butoxide and stir at -78° C. for 2 hours. Add 89.12 g p-chlorobenzaldehyde in 200 ml THF to cold reaction mixture and stir for 30 minutes. Add 142.3 g potassium tert.-butoxide and then allow to warm to room temperature. After 18 hours, add 500 ml saturated aqueous ammonium chloride solution and 500 ml H2O and extract with 500 ml diethyl ether. Wash organic layer with 2×400 ml saturated aqueous sodium chloride solution, dry over magnesium sulfate, filter and evaporate solvent to dryness. Wash residue with 200 ml hexane and filter off precipitate. Evaporate hexane and dissolve material in 150 ml hexane methylene chloride (66:33) solution and elute through column containing 300 g silica gel (Merck 60-230 mesh) with hexane: methylene chloride (66:33) solution. Monitor column chromatography using thin-layer chromatography on silica gel (hexane: methylene chloride, 66:33). Collect desired fraction and evaporate solvent. Distill residue in vacuo and collect fraction boiling at 65° C. (8.5 mmHg) to obtain the title compound.

Quelle