Phosphorus oxychloride → 4-Chloro-3-nitro-1,5-naphthyridine

Participants

Reaction Steps

Phosphorus oxychloride (31.7 mL, 340 mmol) was added dropwise to a stirred suspension of 3-nitro[1,5]naphthyridine-4-ol (50.0 g, 262 mmol) in 350 mL of DMF that was cooled with a water bath surrounding the reaction vessel. The resulting green suspension was stirred at ambient temperature for 5 hours and poured into 1.5 L of ice water and stirred for an additional hour. The suspension was filtered, washed with water (3×150 mL), and the resulting orange filter cake was dissolved in dichloromethane (800 mL) and washed with saturated aqueous sodium bicarbonate. The layers were separated and the organic layer was dried over magnesium sulfate, filtered, and concentrated under reduced pressure to afford 50.49 g of 4-chloro-3-nitro[1,5]naphthyridine as an orange solid.

Provenance & Evidence