Stannous chloride dihydrate → 5-Amino-7-bromo-6-chloro-1,4-dihydro-2,3-quinoxalinedione
Reaction equation
[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([NH:6][C:7](=[O:13])[C:8](=[O:12])[NH:9]2)=[C:4]([N+:14]([O-])=O)[C:3]=1[Cl:17].O.O.[Sn](Cl)Cl.C([O-])(O)=O.[Na+]>C(O)C>[NH2:14][C:4]1[C:3]([Cl:17])=[C:2]([Br:1])[CH:11]=[C:10]2[C:5]=1[NH:6][C:7](=[O:13])[C:8](=[O:12])[NH:9]2Participants
5
Reactant 3
Product 1
Reagents, catalysts & solvents 1
Procedure
A suspension of 7-bromo-6-chloro-5-nitro-1,4-dihydro-2,3-quinoxalinedione (50 mg, 0.16 mmol) and tin (II) chloride dihydrate (176 mg, 0.780 mmol, Aldrich, used as received) in ethanol (5 mL) was refluxed for 7 h. It was then cooled to r.t. and poured into ice (10 g). The suspension was then basified with 10% aq. NaHCO3 (25 mL) to pH 8-8.5 (pH paper) and extracted with ethyl acetate (50 mL). The ethyl acetate extract was washed with water and brine, dried over Na2SO4 and evaporated to give a solid which was dried under high vacuum to furnish 28 mg (62%) of pure title compound as a brown powder, m.p.>350° C.; 1H NMR (DMSO-d6) δ5.888 (br s, 2H), 6.075 (s, 1H), 11.286 (s, 1H), 11.827 (s, 1H).
Workup
- temperaturewas refluxed for 7 h
- extractionextracted with ethyl acetate (50 mL)
- extractionThe ethyl acetate extract
- washwas washed with water and brine
- dry with materialdried over Na2SO4
- customevaporated
- customto give a solid which
- customwas dried under high vacuum
Sources & evidence
- ORD record
- ord-051d04fe2fcd4d329f6200292f380243
- Source dataset
- uspto-grants-1997_04
- Patent number
- US05622952
Reaction notes
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