Reaktion #527664

Reaktionsgleichung

(-)-1-[1-(2-bromophenyl)cyclobutyl]-6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline

hydrobromic acid

→

(+)-1-[1-(2-bromo-phenyl)cyclobutyl] -6,7-dihydroxy-2-methyl-1,2,3,4-tetrahydroisoquinoline hydrobromide

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturunder reflux for 5 hours
3. 3
   SonstigeThe solvent was removed by evaporation
4. 4
   Sonstigethe residue dried
5. 5
   workup.DISTILLATIONdistillation with propan-2-ol
6. 6
   workup.DISSOLUTIONThe residue was dissolved in propan-2-ol
7. 7
   Sonstigeprecipitated with ether
8. 8
   SonstigeThe resulting solid was dried in vacuo at 45° C.

Vorschrift

A mixture of (-)-1-[1-(2-bromophenyl)cyclobutyl]-6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline (1.46 g), 48% aqueous hydrobromic acid (20 ml) and glacial acetic acid (20 ml) was heated under reflux for 5 hours. The solvent was removed by evaporation and the residue dried by repeated azeotropic distillation with propan-2-ol. The residue was dissolved in propan-2-ol and precipitated with ether. The resulting solid was dried in vacuo at 45° C. to yield (+)-1-[1-(2-bromo-phenyl)cyclobutyl] -6,7-dihydroxy-2-methyl-1,2,3,4-tetrahydroisoquinoline hydrobromide [m.p. 207°-209° C. (dec)] which had a specific optical rotation αD of +38.2°.

Quelle