Iodine → 8-Hydroxy-2,2,4-trimethyl-1,2-dihydro-6-oxa-1-azachrysen-5-one

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Reaction Conditions

Reaction Steps

In a pressure tube, 8-amino-3-hydroxybenzo[c]chromen-6-one (Reference Compound No. 1-1-(3), 40.0 g, 176 mmol) was dissolved in acetone (440 mL)-N-methylpyrrolidone (240 mL), iodine (17.9 g, 70.5 mmol) was added thereto, the pressure tube was sealed, and then the reaction mixture was stirred at 110° C. for 3 days. After cooling down, acetone was removed under reduced pressure. To the obtained residue, ethyl acetate (700 mL), hexane (150 mL) and 1% aqueous sodium thiosulfate solution (700 mL) were added thereto and the mixture was separated into a water phase and an organic layer. The water layer was extracted with a mixed solvent of ethyl acetate (250 mL)-hexane (50 mL) (3 times). The combined organic layer was washed with water (500 mL, 3 times) and saturated brine (500 mL) successively, dried over anhydrous magnesium sulfate, and then the solvent was removed under reduced pressure. To the obtained residue, chloroform (150 mL) was added and the unsoluble materials were filtered out. After the filtrate was concentrated, the residue was purified by silica gel column chromatography (hexane-ethyl acetate) to give the titled reference compound (26.0 g) as a yellow solid. (Yield 48%)

Provenance & Evidence