Benzoyl chloride → HCID 363110, compound
Reaction equation
[CH2:1]1[C:13]2[NH:12][C:11]3[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=3)[C:5]=2[CH2:4][CH2:3][NH:2]1.[C:14](Cl)(=[O:21])[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1>>[C:14]([N:2]1[CH2:3][CH2:4][C:5]2[C:6]3[C:11](=[CH:10][CH:9]=[CH:8][CH:7]=3)[NH:12][C:13]=2[CH2:1]1)(=[O:21])[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1Participants
Procedure
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.
Sources & evidence
- ORD record
- ord-03dc6817f0c84aec85bf3f9ec0f7c672
- Source dataset
- uspto-grants-1981_08
- Patent number
- US04283536
Reaction notes
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