Ammonium Hydroxide → 8-Fluoro-6-methylphenanthridine

Participants

Reaction Conditions

Reaction Steps

N-(4′-Fluorobiphenyl-2-yl)-acetamide (18.5 g, 80.7 mmol) was mixed with polyphosphoric acid (250 g) and then heated to 120° C. with vigorous stirring for 48 hours. The hot reaction mixture was poured onto ice and stirred vigorously until homogeneous. Concentrated ammonium hydroxide was added until the pH >9. A white precipitate formed. The mixture was filtered and the white solid was dissolved in ethyl acetate (250 mL) and filtered. The filtrate was washed with saturated, aqueous sodium chloride, dried over anhydrous sodium sulfate, filtered, and reduced in vacuo to a brown solid. The solid was purified by recrystallization from ethyl acetate-hexane to afford 8-fluoro-6-methylphenanthridine as white crystals (15.9 g, 94% ), m.p. 92-93° C.

Provenance & Evidence