HCID 178498355, compound → HCID 13050867, compound

Participants

Reaction Steps

In 20% aqueous sodium hydroxide was dissolved methyl 2-(3,5-dihydroxy-1,4-naphthoquinon-2-yl)-3-methoxy-5-methyl-6-chlorobenzoate as obtained in (1) and the solution was refluxed for 3 hours. The reaction mixture was allowed to cool, acidified, and extracted with ethyl acetate. The solvent layer was washed with water and dried. The solvent was then distilled off and the residue was dissolved in tetrahydrofuran (2 ml). After addition of acetic anhydride (2 ml), the crystals that separated out were recovered by filtration, washed with diethyl ether and dried to give crystals (70 mg) of 4-chloro-8-hydroxy-1-methoxy-3-methyl-7,12-dihydro-5H-benzo[d]naphtho[2,3-b]pyran-5,7,12-trione.

Provenance & Evidence