Allyl chloroformate → carbonic acid allyl ester 3-(1-methyl-1H-indol-3-yl)-4-(1-methyl-6-nitro-1H-indol-3-yl)-2,5-dioxo-2,5-dihydro-pyrrol-1-ylmethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 200 mg (0.47 mmole) of 1-hydroxymethyl-3-(1-methyl-1H-indol-3-yl)-4-(1-methyl-6-nitro-1H-indol-3-yl)-pyrrole-2,5-dione, prepared as in the example 1a, was dissolved in 90 ml of THF and treated with 300 mg (2.5 mmol) of 4-dimethylaminopyridine (DMAP). To this solution at 5° C. was added 90 mg (0.75 mmole) of allyl chloroformate. While still cool, 300 mg (2.4 mmol) of 1,5-diazabicyclo(4.3.0)non-5-ene (DBN) (Aldrich) was added dropwise. This was stirred for 14 hours at 20° C. The solvent was evaporated and the mixture was purified by chromatography using silica gel and eluting with a mixture of EtOAc/Hexane to afford carbonic acid allyl ester 3-(1-methyl-1H-indol-3-yl)-4-(1-methyl-6-nitro-1H-indol-3-yl)-2,5-dioxo-2,5-dihydro-pyrrol-1-ylmethyl ester as a red solid (m.p. 191-194° C.).

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