反应详情

Hydrazine hydrate (696 μl, 716 mg, 14.3 mmol) was added dropwise to a solution of N-(6,7-dichloro-2,3-dimethoxyquinoxalin-5-yl)-N-(2-phthalimidoethyl)methanesulphonamide (3.76 g, 7.15 mmol) in a mixture of dichloromethane (71 ml) and methanol (5 ml) at room temperature under nitrogen. The mixture was heated at reflux for 4 days and then further methanol (20 ml) was added. After a further 2 days the mixture was allowed to cool and was concentrated under reduced pressure. The residue was dissolved in ethyl acetate and this was extracted 3 times with 10% aqueous citric acid. The combined acid extracts were adjusted to pH 9 with solid potassium carbonate and extracted 3 times with dichloromethane. The combined dichloromethane extracts were dried (MgSO4) and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel eluting with 95:5 dichloromethane:methanol to give N-(6,7-dichloro-2,3-dimethoxyquinoxalin-5-yl)-N-(2-aminoethyl)methanesulphonamide (1.96 g, 69%) as a pale yellow solid.

1. temperatureThe mixture was heated
2. temperatureat reflux for 4 days
3. temperatureto cool
4. concentrationwas concentrated under reduced pressure
5. dissolutionThe residue was dissolved in ethyl acetate
6. extractionthis was extracted 3 times with 10% aqueous citric acid
7. extractionextracted 3 times with dichloromethane
8. dry with materialThe combined dichloromethane extracts were dried (MgSO4)
9. concentrationconcentrated under reduced pressure
10. customThe residue was purified by flash chromatography on silica gel eluting with 95:5 dichloromethane