Water → 5-Bromo-7-trifluoromethyl-3-(hydroxyimino)-1,4-dihydroquinoxalin-2-one

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Reaction Conditions

Reaction Steps

An adaptation of the method of Harsanyi et al., Liebigs Ann. Chem. 190 (1973) was used. A mixture of 5-bromo-7-trifluoromethyl-3-aminoquinoxalin-2(1H)-one (75 mg, 0.24 mmol) and hydroxylamine hydrochloride (38 mg, 0.54 mmol; Aldrich Co.) in 3 mL of 1-butanol was heated to reflux. The resulting suspension was stirred under reflux for 12 h. The resulting suspension was cooled to 25° C., and H2O was added (6 mL). A pale yellow precipitate appeared. The mixture was vacuum filtered and the solid was washed with EtOH (5×2 mL) and dried in vacuum at 60° C. overnight to yield 67 mg (86% ) of 5-bromo-7-trifluoromethyl-3-(hydroxyimino)-1,4-dihydroquinoxalin-2-one (tentatively named as this since the regiochemistry is not sure) as a pale yellow solid of a new compound: mp 221°-223° C. 1H NMR (300 MHz, DMSO-d6) δ 11.205 (br s, 1H, NH), 10.393 (br s, 1H, NH), 7.639 (s, 1H, H-7), 7.435 (s, 1H, H-5). LRMS: 323 (M+, 80%), 293 (100%).

Provenance & Evidence