Benzoyl chloride → HCID 363110, compound

Participants

Reaction Steps

A tetrahydro-β-carboline (II) is reacted with benzoyl chloride to provide a 2-benzoyl-1,2,3,4-tetrahydro-9H-pyrido-(3,4-b)-indole (III). Then compound (III) is reduced to give a 2-benzyl-1,2,3,4-tetrahydro-9H-pyrido-(3,4-b)-indole (IV). Thereafter, compound (IV) is transformed by t-butyl hypochlorite into a chloroindolenine derivative (V) which is immediately treated with a metal dialkylmalonate such as thallium t-butyl methyl malonate to give a dialkyl 3-benzyl-1,2,3,4,5,6-hexahydroazepino-(4,5-b)-indole-5,5-dicarboxylate (VI). Compound (VI) is then partly decarboxylated into a alkyl 3-benzyl-1,2,3,4,5,6-hexahydro-(4,5-b) indole-5-carboxylate (VII). Compound (VII) is hydrogenated to give an alkyl 1,2,3,4,5,6-hexahydroazepino-(4,5-b)-indole 5-carboxylate (VIII). In an alternative embodiment, compound (VI) can be hydrogenated to the corresponding dialkyl 1,2,3,4,5,6-hexahydroazepino-(4,5-b)-indole-5,5-dicarboxylate which is then decarboxylated into compound (VIII). Compound (VIII) is condensed with a functionalised aldehyde, typically a epoxy aldehyde or a haloaldehyde such as 1-bromo-4-formylhexane, to give vincadifformine or similar pentacyclic derivatives.

Provenance & Evidence