Benzylamine → N-phenylmethyl-3-nitro[1,5]naphthyridin-4-amine

Participants

Reaction Conditions

Reaction Steps

Phosphorus oxychloride (3.5 mL, 37.7 mmol) was reacted with N,N-dimethylformamide (15 mL) while chilling in an ice bath. This mixture was added to a solution of 3-nitro[1,5]naphthyridin-4-ol (6.0 g, 31.4 mmol) in N,N-dimethylformamide (60 mL). The reaction mixture was warmed in an oil bath to 60° C. After 3 hours the reaction mixture was poured into ice water. The resulting precipitate was isolated by filtration and then washed with water. The wet crude 5-chloro-3-nitro[1,5]naphthyridine was suspended in dichloromethane (150 mL). Diisopropylethylamine (1.2 eq) was added followed by the slow addition of benzylamine (4.7 mL g, 40 mmol). The reaction mixture was refluxed for 2 hours and then combined with water (˜100 mL). The layers were separated and the organic layer was concentrated under vacuum to provide 5.5 g of N-phenylmethyl-3-nitro[1,5]naphthyridin-4-amine. A small sample was recrystallized from isopropanol to provide a pure sample, m.p. 127-129° C. Analysis: Calculated for C15H12N4O2: %C, 64.28; %H, 4.32; %N, 19.99. Found: %C, 63.89; %H, 4.40: %N, 20.35.

Provenance & Evidence