Hydrogen Bromide → HCID 13146271, compound

Participants

Reaction Steps

Treatment of 9(R)-acetoxyacetyl-6,9,11-trihydroxy-5,7,8,9,10,12-hexahydronaphthacene-5,12-dione (3.5 g) with bromine (3.41 g) was effected in a refluxing mixture of chloroform (875 ml) and carbon tetrachloride (1750 ml) with heating for 3 hours, while the reaction mixture was irradiated with 500 W lamp as radical reaction initiator in the presence of cyclohexene oxide (2.51 g) as a scavenger of the generated HBr. The solvent was removed under reduced pressure and ether (52.5 ml) was added to the residue. The resultant mixture was stirred at room temperature for 1.5 hours and precipitated crystals were filtered to give reddish orange powders of 7-bromo-9(S)-acetoxyacetyl-6,9,11-trihydroxy-5,7,8,9,10,12-hexahydronaphthacene-5,12-dione. M.P., 173°-175° C.

Provenance & Evidence