Phosphorus oxychloride → 7-Bromo-4-chloro-3-nitro[1,5]naphthyridine

Participants

Reaction Steps

Phosphorous oxychloride (24 mL, 257.7 mmol) was added slowly dropwise to a 0° C. suspension of 7-bromo-3-nitro[1,5]naphthyridin-4-ol (60.00 g, 222.2 mmol) in N,N-dimethylformamide (DMF; 410 mL), maintaining the temperature below 10° C. After addition was completed, the reaction was allowed to warm to ambient temperature over a 3 hour period. The reaction mixture was then added to ice water (1700 mL) with stirring. A solid precipitate formed, which was isolated by vacuum filtration and rinsed with water. The material was partitioned between chloroform (3 Liters) and saturated aqueous sodium bicarbonate (300 mL). The organic phase was isolated, dried over anhydrous sodium sulfate, then concentrated under reduced pressure to yield 54.42 g of 7-bromo-4-chloro-3-nitro[1,5]naphthyridine as short, off-white needles.

Provenance & Evidence