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

HRID 235302Notes

Reaction equation

[Cl: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>[Cl: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]2

Participants

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-chloro-7-trifluoromethyl-3-aminoquinoxalin-2(1H)-one (35 mg, 0.13 mmol) and hydroxylamine hydrochloride (20 mg, 0.29 mmol; Aldrich Co.) in 2 mL of 1-butanol was heated to reflux. The resulting suspension was stirred under reflux for 12 h. The resulting suspension was cool to 25° C., and added H2O (5 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 25 mg (69%) of 5-chloro-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 dec.>235° C. 1H NMR (300 MHz, DMSO-d6) δ 11.199 (br s, 1H, NH), 10.932 (br s, 1H, NOH), 10.411 (br s, 1H, NH), 7.604 (s, 1H, H-7), 7.317 (s, 1H, H-5). LRMS: 279 (M+, 100%), 249 (50%).

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-20a864e2a391445fbf82b592ab987570
Source dataset: uspto-grants-1997_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05597922

Reaction notes

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