Study on Synthesis and Fluorescence of Novel Benzofused Phenazine π-Conjugated Skeleton with Coumarin and Isophoron Cores

Abstract

The novel benzofused phenazine π-conjugated skeleton with a coumarin and isophoron core was synthesized, characterized, and condensed with suitably substituted active methylene compounds by classical Knoevenagel condensation reaction to obtain novel mono-styryl dyes 6a-6d. These novel styryl dyes have hue varying from yellow to violet. The geometries of the styryl dyes were optimized at B3LYP/6-31G (d) level of theory, and their electronic excitation properties were evaluated using density functional theory.

A review on lawsone-based benzo[a]phenazin-5-ol: synthetic approaches and reactions

“…The compounds 236 or 237 on treatment with 238 or 239 active methylene compounds, respectively, in the DMSO/ethanol in the presence of catalytic amount of piperidine atreflux temperature (70–80 °C) for 4–5 h gave ( E )-2-(3-(5-hydroxybenzo[ a ]phenazin-6-yl)-1-(2-oxo-2 H -chromen-3-yl)allylidene)malononitrile 235a–b and ( E )-2-(3-(5-chlorobenzo[ a ]phenazin-6-yl)-1-(2-oxo-2 H -chromen-3-yl)allylidene) malononitrile 235c–d ( Scheme 71 ). 102 …”

Enolizable Alkylidene Heterocyclic and Carbocyclic Carbonyl Systems­: Valuable Vinylogous Donor Substrates in Synthesis

“…This substrate, indeed, has been mainly and widely exploited for more than 15 years in the context of aldol condensation chemistry using a plethora of aromatic aldehydes as acceptor components. [107][108][109][110][111][112][113][114][115][116][117][118][119] One of the first reports dates back to 2000, when 120a was coupled to p-aminobenzaldehydes 38 under basic treatment 107 to obtain highly conjugated achiral products 193 (Scheme 66).…”

“…These characteristics confer those physical requisites (including high dipole moment and polarizability anisotropy, reduced dielectric strength and reduced tendency to crystallize) that are key for their use as chromophoric dopants in photorefractive polymer composites, stimulusresponsive dyes, or fluorescent biocompatible probe. [108][109][110][111][112][113][114][115][116][117][118][119] Finally, the vinylogous aldol condensation of isophorone-derived 120a with pyrazole 194 (Scheme 67) was reported in 2012 120 as the starting reaction in a multi-step sequence directed toward the synthesis and antimicrobial evaluation of benzo [b]thiophene-β-lactam congeners. The dicyanoolefin moiety within product 195 served then to construct the fused thiophene heterocycle in the advanced intermediate 196 and in the β-lactam targets (not shown).…”