Thermolysis of Chlorovinyl Imines as an Alternate Route for the Synthesis of Pyranoquinolin‐3‐one and Pyranoacridin‐3‐one Derivatives

Abstract

Synthesis of 3H‐pyrano[3,2‐f]quinolin‐3‐one and 3H‐benzo[h]pyrano[3,2‐a]acridin‐3‐one derivatives are described by the thermolysis of suitable chlorovinyl imine derivatives. The chlorovinyl imines were obtained by condensation of suitable β‐chloro‐α,β‐unsaturated aldehydes and 6‐aminocoumarin in methanol at 15°C. Compounds showed blue fluorescence in alkaline medium.

Synthesis of pyrimido[4,5- b ]quinolindiones and formylation: ultrasonically assisted reactions

“…The ultrasonically assisted reactions described in this study offer a simple, facile and ecofriendly procedure for the efficient synthesis of pyrimido [4,5-b]quinoline-4,6-diones and VH formylation, generating stable solids with good efficiency in a few minutes. β-Chlorovinyl aldehydes are 1,3-bi-electrophilic systems with excellent and useful features for a variety of cyclization and heterocyclization reactions [47][48][49][50][51] with substrates having bi-nucleophilic properties. To experimentally verify this reaction with our β-chlorovinyl aldehyde derivatives, we initiated a reaction between 6-chloro-5-(4-chlorophenyl)-3,8,8-trimethyl-2-(methylthio)-4-oxo-3,4,5,8,9,10-hexahydropyrimido[4,5-b]quinoline-7-carbaldehyde 6d and hydrazine as the ambident nucleophile.…”

An Overview on the Synthesis of Fused Pyridocoumarins with Biological Interest

“…Oxidation of compounds 146a – c with DDQ resulted in the fully aromatic 3 H -benzo[ h ]pyrano [3,2- a ]acridine-3-one derivatives 150a – c . A few years later, in 2017, Patra performed a modification of the above three-component reaction by using only one equivalent of 7-aminocoumarin ( 57a ) and β-chloro-α,β-unsaturated aldehydes in methanol at 15 °C without the presence of hydrochloric acid [ 118 ]. This procedure led to the preparation of the intermediate chlorovinyl imine derivatives 151a , b and 152a – d ( Scheme 33 ).…”

A Concise Review on Pyridocoumarin/Azacoumarin Derivatives: Synthesis and Biological Activity

“…Recently, we reported the synthesis of pyranoquinolin‐3‐one and pyranoacridin‐3‐one derivatives by thermolysis of chlorovinyl imines which can be prepared from various β‐chloro‐α,β‐unsaturated aldehyde derivatives and 6‐amino coumarin in MeOH solvent at 15 °C (Scheme ). The process saved the consumption of one equivalent 6‐amino coumarin.…”