Methanol → 4-[(3-Fluoro-6-methylphenanthridin-5(6H)-yl)sulfonyl]phenol

Participants

Reaction Conditions

Reaction Steps

To a stirred slurry of 3-fluoro-5-[(4-methoxyphenyl)sulfonyl]-6-methyl-5,6-dihydrophenanthridine (262 mg, 0.68 mmol) in cyclohexene (1.38 mL, 14 mmol) under an inert atmosphere of nitrogen was added a 1 M solution of boron tribromide in dichloromethane (4.1 mL). The progress of the reaction was monitored by thin-layered chromatography and after 2.5 hours the reaction was deemed complete. The reaction contents were cooled to 0° C. and methanol was added slowly. The volatile components were removed in vacuo and the crude residue was purified by preparative liquid chromatography on a Biotage® 40 Mi column of prepacked silica gel (90 g), eluting with a gradient of 30%-50% methyl tert-butyl ether in hexane, to afford the title compound (77 mg, 30%) as a solid, m.p. 162-165° C.;

Provenance & Evidence