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New Route of Benzyne Cyclization for Synthesis of 2,3,4,5‐Tetrahydro‐1H‐pyrido[4,3‐b]indole Derivatives Avoiding Highly Toxic Aryl Hydrazines
Author(s) -
Kovacikova Lucia,
Stefek Milan
Publication year - 2014
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.2150
Subject(s) - chemistry , indole test , aryne , regioselectivity , toluene , dimethoxyethane , solvent , aryl , organic chemistry , alkyl , isocyanate , medicinal chemistry , catalysis , electrolyte , electrode , polyurethane
A new route for the regioselective synthesis of 2,3,4,5‐tetrahydro‐1H‐pyrido[4,3‐b]indole derivatives was developed based on cyclization of 3‐chlorophenylimine‐N‐alkyl‐4‐piperidones by “the complex bases” of NaNH 2 or KNH 2 . The procedure was performed under variable reaction conditions in inert proton‐free solvents, such as THF, dioxane, 1,2‐dimethoxyethane, toluene, and xylene, at temperatures varying from 20°C to boiling point of the solvent used. Toxic arylhydrazine intermediates occurring in the classical Fischer indole synthesis are avoided.