Pyridinium chloride → 3-Bromo-7,9-dihydroxy-10,11-dihydrodibenz[b,f]oxepin-10-one

Participants

Reaction Conditions

Reaction Steps

To 395 mg (F.W. 349.18, 15.75 mmol) of dimethoxylated compound (27) was added 2.0 g of pyridine hydrochloride and stirred at 195° C. for 1.5 hours and then, ice water was slowly added thereto. The resulting solution was extracted with ethyl acetate and the extract was washed with 1N hydrochloric acid, water and a saturated sodium chloride aqueous solution in the order named. The extract thus washed was dried with anhydrous magnesium sulfate and then, concentrated. The residue was purified by silica gel column chromatography (developing solvent; ethyl acetate:hexane=1:2). Furthermore, the product thus obtained was recrystallized from dioxane and dioxane-hexane to obtain 223 mg (61%) of the title compound. (TLC; ethyl acetate:hexane=1:2).

Provenance & Evidence