Water → 5-Bromo-7-trifluoromethyl-3-(hydroxyimino)-1,4-dihydroquinoxalin-2-one
Reaction equation
[Br:1][C:2]1[CH:11]=[C:10]([C:12]([F:15])([F:14])[F:13])[CH:9]=[C:8]2[C:3]=1[N:4]=[C:5]([NH2:17])[C:6](=[O:16])[NH:7]2.Cl.N[OH:20].O>C(O)CCC>[Br:1][C:2]1[CH:11]=[C:10]([C:12]([F:14])([F:15])[F:13])[CH:9]=[C:8]2[C:3]=1[NH:4][C:5](=[N:17][OH:20])[C:6](=[O:16])[NH:7]2Participants
Conditions
- Temperature
- 25 °C
Procedure
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%).
Workup
- temperaturewas heated to reflux
- temperatureunder reflux for 12 h
- filtrationfiltered
- washthe solid was washed with EtOH (5×2 mL)
- customdried in vacuum at 60° C. overnight
Sources & evidence
- ORD record
- ord-bd8bfe9ce69b45e8ae4b0d3acaf1c89c
- Source dataset
- uspto-grants-1997_01
- Patent number
- US05597922
Reaction notes
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