Phosphorus oxychloride → 2-Chloro-8-fluoroquinoline

Participants

Reaction Conditions

Reaction Steps

8-Fluoroquinolin-2(1H)-one (26.0 g, 159 mmol) was slurried with phosphoryl trichloride (163 ml, 1.73 mol, 11 eq) and heated to 125° C. for 2 h. The reaction was cooled to rt and poured onto 1.2 L of ice water with vigorous stirring. When the mixture had cooled to rt, the orange solid was filtered and washed with water and dried under vacuum overnight to afford 27 g of crude material. The crude material was recrystallized from hexanes by dissolving in ˜700 mL of hexanes at reflux and decanting away from residual tar. The hexane solution was cooled to 0° C. and the precipitate 2-chloro-8-fluoroquinoline was filtered. The mother liquor was concentrated in vacuo and recrystallized from hexanes to obtain a second crop of 2-chloro-8-fluoroquinoline (21.3 g, 74% total yield).

Provenance & Evidence