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Synthesis of 5-amino-N'-(9H-fluoren-9-ylidene)-8-nitro-7-aryl-1,2,3,7-tetrahydroimidazo[1,2-a]pyridine-6-carbohydrazide derivatives based on heterocyclic ketene aminals.

ABSTRACT: A new class of tetrahydroimidazo[1,2-a]pyridine derivatives has been successfully prepared via a five-component domino reaction using cyanoacetohydrazide, 9-fluorenone, aromatic aldehydes, 1,1-bis(methylthio)-2-nitroethene and ethylenediamine in ethanol at reflux. The new efficient cascade approach involves a sequence of N,N-acetal formation, Knoevenagel condensation, Michael addition, imine-enamine tautomerization and N-cyclization as key steps. The merit of this protocol is highlighted by its available and economical starting compounds, operational simplicity, clean reaction profile and tolerance of a wide diversity of functional groups.

SUBMITTER: Hosseini H

PROVIDER: S-EPMC9091710 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature

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Synthesis of 5-amino-N'-(9H-fluoren-9-ylidene)-8-nitro-7-aryl-1,2,3,7-tetrahydroimidazo[1,2-a]pyridine-6-carbohydrazide derivatives based on heterocyclic ketene aminals.

Hosseini Hajar H Bayat Mohammad M

RSC advances 20181211 72

A new class of tetrahydroimidazo[1,2-a]pyridine derivatives has been successfully prepared via a five-component domino reaction using cyanoacetohydrazide, 9-fluorenone, aromatic aldehydes, 1,1-bis(methylthio)-2-nitroethene and ethylenediamine in ethanol at reflux. The new efficient cascade approach involves a sequence of N,N-acetal formation, Knoevenagel condensation, Michael addition, imine-enamine tautomerization and N-cyclization as key steps. The merit of t ...[more]

PMID: 35559289

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