Novel synthesis of 2‐aminoquinoline‐3‐carbaldehyde, benzo[b][1,8]naphthyridines and study of their fluorescence behavior

Abstract

A novel route was successfully developed for the synthesis of new synthons, orthoamino formyl quinoline (heterocyclic orthoaminoaldehyde) and utilized for the synthesis of series of benzonaphthyridines by Friedländer condensation reactions with benzoylacetonitrile. The benzonaphthyridines synthesized were further studied for their fluorescence properties. Copyright © 2010 John Wiley & Sons, Ltd.

Luminescent benzo- and naphthoquinolines: Synthesis and investigation of photophysical properties

“…We also obtained important material characteristics and compared them among molecules. Those were values of the HOMO (E HOMO ¼[ À 5,9; À 5,5] eV), the LUMO (E LUMO ¼[ À 3,6; À3] eV) energy levels together with optical band gap (E g_opt ¼[2; 2, 8] eV), Stokes' shift (Δλ Stokes' ¼ [64; 155] nm), differences between PL spectra in thin film and chloroform solution (Δλ PL ¼[ À42, 84] nm) and solvatochromism (comparing PL in toluene, chloroform and 2-methoxyethanol (Δλ ¼ [12,77] nm)). It was noticed, that the value of optical band gap E g increases (for all molecular size groups) with changing substituents in such order: amine (smallest E g ), tetrazole, iminophosphorane, chlorine.…”

“…Different investigated derivatives of quinoline were synthesized in the same manner (Scheme 1) [12].…”

“…Synthesis of some materials (2a, 3a, 4a, 5a and 5g) has been already described publicly [7,[12][13][14]29] yet the significance of our study is that we compare photophysical properties of solution and thin-film of newly synthesized molecules with their already mentioned analogues. This allows us to present not only complex information about detailed process of synthesis, but also some insights regarding molecular structure influence on photophysical material properties.…”

2,4,6-Trichloro-1,3,5-triazine and N,N′-dimethylformamide as an effective Vilsmeier–Haack reagent for the synthesis of 2-chloro-3-formyl quinolines from acetanilides

“…Few of these composites exhibited good antimicrobial activity. Shelar et.al developed a novel route for the synthesis of ortho amino formyl quinoline (heterocyclic ortho amino aldehyde) which in turn was utilized for the synthesis of series of benzonaphthyridines which exhibited excellent fluorescent properties 32 .Over the years, the Vilsmeier-Haack (VH) reagent is used as an efficient, economical and mild reagent for the formylation of aromatic and heteroaromatic substrates. Basically, DMF and oxychloride under chilled conditions 33 in situ forms a chloromethyleniminium salt, which is used as a powerful synthetic tool to achieve several aromatic and heterocyclic compounds including quinoline derivatives [34][35][36][37][38][39][40] .…”

An efficient Synthesis and Photophysical Properties of 1H-pyrazolo-[3,4-b]pyridine and pyrazolo[3,4-b][1,8]naphthyridines

“…From literature it was also noted that 1,8-naphthyridine derivatives were not only use as luminescence materials in molecular recognition because of their rigid planer structure [6][7][8], possess antibacterial [9], antymicobacterial [10], antitumoral [11], anti-inflammatory [12], antiplatelet [13], gastric antisecretary [14], antiallergic [15] and local anaesthetic [16]. Recently, our research group reported systematic studies about the fluorescence properties of differently substituted pyrazolofused heterocycles [17][18][19][20][21][22] and benzo naphthyridines [23][24][25][26]. Annulation reactions with hetrocyclic aminoaldehydes provides synthectic entry into hetrocyclic systems, fused to a pyridine or pyrimidine nucleus by Friedlander condensation reactions with reactive methylenes.…”