反应详情

A solution of 2-(4-(methylthio)benzyl)isoindoline-1,3-dione (preparation 6a, 3.60 g, 12.71 mmol), cyanamide (694 mg, 16.5 mmol) and potassium tert-butoxide (1.71 g, 15.25 mmol) in methanol (30 mL) is treated with N-bromosuccinimide (3.39 g, 19.06 mmol). The mixture is stirred for 1 h and concentrated under reduced pressure. Saturated aqueous Na2S2O3 solution is added and the mixture is extracted twice with dichloromethane. The combined organic layers are dried over Na2SO4 and concentrated under reduced pressure. The residue is purified by flash chromatography on silica (gradient cyclohexane/ethyl acetate 1:1 to ethyl acetate to ethyl acetate/methanol 4:1). Yield: 2.43 g (59% of theory); ESI mass spectrum: [M+H]+=324; r.t. HPLC: 0.52 min (X001_004).

1. concentrationconcentrated under reduced pressure
2. additionSaturated aqueous Na2S2O3 solution is added
3. extractionthe mixture is extracted twice with dichloromethane
4. dry with materialThe combined organic layers are dried over Na2SO4
5. concentrationconcentrated under reduced pressure
6. customThe residue is purified by flash chromatography on silica (gradient cyclohexane/ethyl acetate 1:1 to ethyl acetate to ethyl acetate/methanol 4:1)
7. customr.t
8. custom0.52 min (X001_004)