Reaktion #703596

Reaktionsgleichung

water

3-(p-biphenylyl)-but-1-yn-3-ol

ammonium bromide

→

1-bromo-3-(p-biphenylyl)-1,2-butadiene

Lösungsmittel

hydrobromic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   Extraktionextracted 3 times with 8 ml portions of methylene chloride
2. 2
   WaschenThe combined organic extracts are washed 3 times with water
3. 3
   Sonstigedried over anh. S.S
4. 4
   Filtration, filtered
5. 5
   Sonstigeevaporated (i.v.) to dryness
6. 6
   Sonstigeto obtain a residue
7. 7
   SonstigeThe residue is chromatographed on silica gel
8. 8
   SonstigeThe solvent is removed by evaporation
9. 9
   Sonstigeto obtain a residue
10. 10
    Sonstigefrom which 1-bromo-3-(p-biphenylyl)-1,2-butadiene is crystallized from pentane

Vorschrift

A suspension of 1.1 g of 3-(p-biphenylyl)-but-1-yn-3-ol (obtainable analogously to Steps A and B, Example 10), 1.8 g of ammonium bromide and 0.2 g cuprous chloride in 10 ml of 48% hydrobromic acid is stirred for 4 hours at room temperature. The reaction mixture is then poured into water and extracted 3 times with 8 ml portions of methylene chloride. The combined organic extracts are washed 3 times with water, dried over anh. S.S., filtered and evaporated (i.v.) to dryness to obtain a residue. The residue is chromatographed on silica gel using chloroform/pentane (1:1) as eluent. The solvent is removed by evaporation to obtain a residue, from which 1-bromo-3-(p-biphenylyl)-1,2-butadiene is crystallized from pentane.

Quelle