Synthesis of new tricyclic 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepine derivatives by [3+ + 2]-cycloaddition/rearrangement reactions
| Autor: | Zi-jie Song, Zhiming Li, Lin-bo Luan, Quan-rui Wang |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
cyclization
Aluminium chloride oxidation rearrangement Substituent 010402 general chemistry 01 natural sciences Medicinal chemistry Adduct lcsh:QD241-441 chemistry.chemical_compound lcsh:Organic chemistry medicine Rearrangement reaction lcsh:Science chemistry.chemical_classification 010405 organic chemistry Organic Chemistry 1 4-benzodiazepine (BDZ) Cycloaddition 0104 chemical sciences Diazepine chemistry hydrazones lcsh:Q Piperidine medicine.drug Tricyclic |
| Zdroj: | Beilstein Journal of Organic Chemistry, Vol 14, Iss 1, Pp 1826-1833 (2018) |
| ISSN: | 1860-5397 |
| DOI: | 10.3762/bjoc.14.155 |
| Popis: | Two new series of tricyclic heterocycles, namely 5,6-dihydro-4H-benzo[b][1,2,4]triazolo[1,5-d][1,4]diazepinium salts 10 and the related neutral, free bases 13 were synthesized from 4-acetoxy-1-acetyl-4-phenylazo-1,2,3,4-tetrahydroquinolines 8 and nitriles 9 in the presence of aluminium chloride by the [3+ + 2]-cycloaddition reaction of the in situ generated azocarbenium intermediates 14 followed by a ring-expansion rearrangement. In the rearrangement reaction, the phenyl substituent in the initially formed spiro-triazolium adducts 16 underwent a [1,2]-migration from C(3) to the electron-deficient N(2). This led to the ring expansion from 6-membered piperidine to 7-membered diazepine furnishing the tricyclic 1,2,4-triazole-fused 1,4-benzodiazepines. |
| Databáze: | OpenAIRE |
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