Synthesis and structure of styryl-substituted azines

Abstract

New photochromic derivatives of 2-styrylquinoline and 2-styrylquinoxaline were obtained by the condensation of the methyl derivatives of the mentioned heterocycles with substituted benzaldehydes in the presence of basic and acidic catalysts, and also under the conditions of Wittig reaction. The structure of compounds obtained was proved by physicochemical analysis methods including XRD.Styryl-substituted derivatives of quinoline and quinoxaline are interesting as compounds with a potential biological activity. The derivatives of quinoline and quinoxaline possess bactericidal and fungicidal properties [1,2]. It was shown recently that quinoline derivatives are promising substrates for the photoinduced electrocyclic reaction [3]. The synthetic potential of these phototransformations is suffi ciently wide and makes it possible to use them for the synthesis of new polyfused heteroaromatic compounds (Scheme 1).π-Conjugated organic compounds based on aromatic systems attract signifi cant attention with respect to the application as semiconductors in organic fi eld transistors (OFETs), organic light-emitting diodes (OLEDs), and photogalvanic batteries, and also as biological active compounds, e.g., potential antitumor agents [4].It is known [5][6][7][8][9][10][11][12] that the main procedure for the synthesis of styrylheterocycles is the aldol-type condensation of methyl derivatives of heterocyclic bases with benzaldehyde derivatives. The primary conditions of the condensation contained the use of relatively strong protic acids and bases, and the range of the possible reaction products was limited. Yet the importance of this condensation as one of the main procedures for the preparation of the polyfunctional products is so high that the development of various versions of its performance becomes nowadays a special fi eld of research.We tested this method for the synthesis of methoxysubstituted 2-styrylquinoline (II). The acidity characteristic of the alkyl groups in the α-position of the pyridine Scheme 1. N X R 2 R 1 hv N X R 2 R 1 and/or N X R 2 R 1 X = CH, N.

Regiospecific C–N Photocyclization of 2-Styrylquinolines

“…Compound 1f was additionally modified with 15-crown-5 ether residue, providing the possibility to influence the photoreaction by complexation with a Mg 2+ cation. Styrylquinolines 1a – 1f were prepared by condensation of quinaldine with the corresponding benzaldehyde derivatives in the presence of KOBu t in DMF according to published protocols. , …”

Synthesis and spectroscopic and structural characterization of three new 2-methyl-4-styrylquinolines formed using Friedländer reactions between (2-aminophenyl)chalcones and acetone

“…This may reflect, at least in part, a lack of efficient, straightforward and versatile routes to other isomeric styrylquinolines. The structure of 2-styrylquinoline itself has been reported three times (Valle et al, 1986;Gulakova et al, 2011;Kuz'mina et al, 2011), as have those of 2-[2-(4-methylphenyl)vinyl]quinoline Kuz'mina et al, 2011;Das et al, 2019) and 2-[2-(3,4methoxyphenyl)vinyl]quinolone (Gulakova et al, 2011;Kuz'mina et al, 2011;Sharma et al, 2021). There are two reports on the structure of 2-[2-(3-nitrophenyl)vinyl]quinoline (Gulakova et al, 2011;Kuz'mina et al, 2011) and one on the structure of 4-phenyl-2-styrylquinoline (Makela et al, 2021).…”

“…The structure of 2-styrylquinoline itself has been reported three times (Valle et al, 1986;Gulakova et al, 2011;Kuz'mina et al, 2011), as have those of 2-[2-(4-methylphenyl)vinyl]quinoline Kuz'mina et al, 2011;Das et al, 2019) and 2-[2-(3,4methoxyphenyl)vinyl]quinolone (Gulakova et al, 2011;Kuz'mina et al, 2011;Sharma et al, 2021). There are two reports on the structure of 2-[2-(3-nitrophenyl)vinyl]quinoline (Gulakova et al, 2011;Kuz'mina et al, 2011) and one on the structure of 4-phenyl-2-styrylquinoline (Makela et al, 2021). In all of these 2-styrylquinolines, the molecular skeleton is planar, in marked contrast to the nonplanar conformations of the 4-styrylquinoline derivatives (I)-(III) reported here, and of those reported previously (Rodrı ´guez et al, 2020).…”

Recent synthetic efforts in the preparation of 2-(3,4)-alkenyl (aryl) quinoline molecules towards anti-kinetoplastid agents

“…Its gentle bromination reaction followed by Pearson protocol (Br 2 , t-BuNH 2 , toluene, À78 C) 62 However, it should be noted that efficient microwaveassisted synthesis for diverse styrylquinolines based on the Perkin condensation reaction under solvent-free conditions have been reported. [66][67][68][69][70][71] This method is not only faster but also improves the yields and constitutes a simple and environmentally friendly alternative for the known procedure. On the other hand, the use of transition metal catalyst in this reaction improved also considerably the yields of this reaction.…”