Ethyl 2-((5-bromo-3-nitropyridin-2-yl)oxy)acetate → 7-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazin-2-one

Participants

Reaction Conditions

Reaction Steps

Iron powder (22.8 g, 408 mmol) was added to a solution of (5-bromo-3-nitro-pyridin-2-yloxy)-acetic acid ethyl ester (2.28 g, 7.47 mmol) in acetic acid (230 mL), and the reaction mixture was heated at 60° C. over 150 min, cooled to room temperature, and filtered. The filtrate was evaporated, taken up in dichloromethane/methanol 1:1 and neutralized with 1 M aq. sodium carbonate solution. The organic layer was washed with water and the aqueous layer re-extracted with dichloromethane. The combined organic layers were washed again with 1 M aq. sodium carbonate solution, dried (Na2SO4), and evaporated to produce 7-bromo-1H-4-oxa-1,5-diaza-naphthalen-2-one (1.46 g, 85%). Off-white solid, MS (ISP)=226.9 (M−H)−.

Provenance & Evidence