New pyrimidines incorporating thiophene and pyrrole moieties: synthesis and electrochemical polymerization

New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties

“…Compounds 2 and 5 ( Scheme 2 ) were further used to synthesize a series of D–π–A–D systems ( 6 – 8 , Scheme 3 ), the so-called quadrupolar chromophores, which are known as prospective building blocks for nonlinear optical materials [ 22 ]. Crotonic condensation of N -substituted carbazole-3-carbaldehydes 2a , b and 1-(5-arylthiophene-2-yl)ethanones 5a , b in the alkaline ethanolic media resulted in the formation of 1,3-diarylsubstituted prop-2-en-1-ones 6a , b [ 23 ]. Cyclization of chalcones 6a , b with guanidine sulfate followed by oxidation with hydrogen peroxide gave rise to 2-amino-4,6-disubstituted pyrimidines 7a , b [ 24 ].…”

N-substituted 2,5-di(2-thienyl)pyrroles: application, production, properties, and electrochemical polymerization (review)

“…By a method similar to the method described in [43][44][45][46][47][48] a group led by G. G. Abashev obtained compounds 21-24 [55,56] The heterocycle 23, containing four thiophene rings, polymerizes best of all, although the peak for the formation of the radical-cation under the chosen conditions has a fairly high value (E a = 0.89, E onset ~ 0,7 V). In compound with the Gewald thiophene residue the radical-cation is formed at a substantially lower potential, E a = 0.65 V, but the polymerization of this heterocycle is not vigorous.…”

“…The synthesis and crystal structure of dithienylpyrrole 23 were presented in [56]. In the reaction of the dithienylpyrrole 22 with carbazole in the presence of potassium carbonate and copper powder in nitrobenzene with boiling for 24 h a new heterocycle 25 was synthesized [57].…”