反应详情

Methanesulphonyl chloride (239 mg, 2.09 mmol) was added to a solution of 6,7-dichloro-2,3-dimethoxy-5-(1-hydroxyethyl)quinoxaline (527 mg, 1.74 mmol) (Preparation 2) and triethylamine (264 mg, 2.61 mmol) in dry dichloromethane (20 mL) at 20° C. The mixture was stirred for 30 minutes, then tetra-n-butyl ammonium chloride (726 mg, 2.61 mmol) was added in portions. After a further 30 minutes at 20° C., brine (20 mL) was added and the organic layer separated. The aqueous layer was extracted with dichloromethane (2×20 mL), and the combined extracts were dried (MgSO4) and concentrated under reduced pressure. Purification by flash chromatography using hexane/dichloromethane (1:1) gave 5-(1-chloroethyl)-6,7-dichloro-2,3-dimethoxyquinoxaline (95 mg, 17%), as a white solid.

1. waitAfter a further 30 minutes at 20° C.
2. customthe organic layer separated
3. extractionThe aqueous layer was extracted with dichloromethane (2×20 mL)
4. dry with materialthe combined extracts were dried (MgSO4)
5. concentrationconcentrated under reduced pressure
6. customPurification by flash chromatography