1,8-Diazabicyclo(5.4.0)undec-7-ene → (E)-5-amino-3,3-dimethyl-6-nitro-1-(pent-2-enyl)-1,3-dihydro-indol-2-one

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Reaction Steps

Analogously to general procedure (I) N-(3,3-dimethyl-6-nitro-2-oxo-2,3-dihydro-1H-indol-5-yl)-acetamide (1.47 g) is alkylated using (E)-1-bromo-2-pentene (1 g; 6.71 mmol) and KOtBu (0.75 g; 6.71 mmol) at RT for 20 h. After aqueous work-up and flash chromatography on silica gel eluting with light petroleum/EtOAc (2.5:1) the pure alkylated acetamide (0.85 g; 2.58 mmol) is de-acetylated under reflux conditions using DBU (0.6 ml) in MeOH (60 ml). (E)-5-amino-3,3-dimethyl-6-nitro-1-(pent-2-enyl)-1,3-dihydro-indol-2-one (0.6 g) is obtained after an aqueous work-up.

Provenance & Evidence