Reaktion #932338

Reaktionsgleichung

bromobenzene

magnesium

4-Dimethylamino-1-phenyl-2-butyn-1-ol

ammonium chloride

→

4-dimethylamino-1,2-diphenyl-2-buten-1-ol

Ausbeute 27.6%

Lösungsmittel

ethyl ether

ethyl ether

ethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeobtained
2. 2
   TemperaturThe reaction mixture is then refluxed for 3 hours and 30 minutes
3. 3
   SonstigeThe organic phase is separated
4. 4
   Extraktionthe aqueous phase is extracted with methylene chloride (2×200 cc)
5. 5
   Trocknendried over magnesium sulphate
6. 6
   Filtrationfiltered
7. 7
   Einengenconcentrated to dryness under reduced pressure (2.7 kPa) at 40° C
8. 8
   SonstigeThe residue is purified by "flash" chromatography [eluent: methanol/ethyl acetate (60/40 by volume)], fractions 18 to 39
9. 9
   Einengenconcentrated to dryness under reduced pressure (2.7 kPa) at 40° C
10. 10
    SonstigeAfter the residue has been recrystallised from isopropyl ether

Vorschrift

A solution of bromobenzene (24.8 g) in ethyl ether (120 cc) is added dropwise over approximately 1 hour to a suspension of magnesium turnings (3.85 g) in ethyl ether (100 cc). 4-Dimethylamino-1-phenyl-2-butyn-1-ol (10 g) in ethyl ether (30 cc) is added over approximately 15 minutes to the black solution obtained. The reaction mixture is then refluxed for 3 hours and 30 minutes, and then poured into a mixture of ice (400 g) and a saturated aqueous solution (200 cc) of ammonium chloride. The organic phase is separated; the aqueous phase is extracted with methylene chloride (2×200 cc); the organic phases are combined, dried over magnesium sulphate, filtered and concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. The residue is purified by "flash" chromatography [eluent: methanol/ethyl acetate (60/40 by volume)], fractions 18 to 39 are combined and concentrated to dryness under reduced pressure (2.7 kPa) at 40° C. After the residue has been recrystallised from isopropyl ether, 4-dimethylamino-1,2-diphenyl-2-buten-1-ol (E) (3.9 g) is obtained in the form of white crystals melting at 113° C.

Quelle