反应详情

4,4′-Dibromo-2,2′-bis-hydroxymethyl-biphenyl 23, the structure of which is shown in Scheme 4 above, (5 g, 0.013 moles, prepared according to the procedure described by D. M. Hall, F. Minhaj, J. Chem. Soc., 1957, 4584) was dissolved in THF (50 ml). HBr (48% wt/wt aqueous solution, 40 ml) was added and the solution refluxed overnight. After this period the THF was removed under reduced pressure and the yellow oil extracted between DCM/H2O (DCM is dichloromethane). The combined organic layers were dried (MgSO4), reduced and recrystallised from acetone (100 ml) to yield 3,9-dibromo-5,7-dihydro-dibenz[c,e]oxepin (12) as fine white crystals (1 g). Repeated recrystallisations of the mother liquor gave further product. Total yield after 3 recrystallisations (2.2 g, 0.0062 moles, 48% yield) as fine white crystals.

1. custom(5 g, 0.013 moles, prepared
2. temperaturethe solution refluxed overnight
3. customAfter this period the THF was removed under reduced pressure
4. extractionthe yellow oil extracted between DCM/H2O (DCM is dichloromethane)
5. dry with materialThe combined organic layers were dried (MgSO4)
6. customrecrystallised from acetone (100 ml)