Nitric Acid → HCID 18695456, compound

Participants

Reaction Steps

δ: 1.16 (6H, d, J=6.1 Hz), 1.60-1.62 (4H, m), 2.32 (2H, t, J=6.7 Hz), 4.01-4.08 (2H, m), 4.87 (1H, q, J=6.1 Hz), 7.01-7.05 (1H, m), 7.18 (1H, dd, J=5.5, 8.6 Hz), 7.32 (1H, dd, J=2.7, 11 Hz), 12.0 (1H, s). 4) In 10 ml of concentrated sulfuric acid cooled on an ice-methanol bath, 1.96 g (6.07 mmol) of isopropyl 5-[2,3-dioxo-7-fluoro-1,2,3,4-tetrahydroquinoxalin-1-yl]valerate was dissolved under stirring. To the resulting mixture, 300 μl of fuming nitric acid was added dropwise at -5° C. or lower, followed by stirring for 30 minutes. The reaction mixture was poured into ice water. The insoluble matter so precipitated was collected by filtration, washed with water and dried under reduced pressure to give 2.06 g (93%) of isopropyl 5-[2,3-dioxo-7-fluoro-6-nitro-1,2,3,4-tetrahydroquinoxalin-1-yl]valerate.

Provenance & Evidence