Push-pull dyes based on Michler's aldehyde: Design and characterization of the optical and electrochemical properties

One-Pot Synthesis of Push–Pull Butadienes from 1,3-Diethyl-2-thiobarbituric Acid and Propargylic Alcohols

“…In this way, a simple decantation and consecutive washing with water, methanol and diethyl ether delivered 3a,b in pure form. The recorded IR, NMR ( 1 H and 13 C{ 1 H}) and HRMS spectra were in full agreement with the characterization data reported by Dumur and co-workers (full details are given in the Materials and Methods section and copies of the spectra included in the Supplementary Materials) [10,11].…”

“…In this way, a simple decantation and consecutive washing with water, methanol and diethyl ether delivered 3a,b in pure form. The recorded IR, NMR ( 1 H and 13 C{ 1 H}) and HRMS spectra were in full agreement with the characterization data reported by Dumur and co-workers (full details are given in the Materials and Methods section and copies of the spectra included in the Supplementary Materials) [10,11]. The synthetic utility of this MW-assisted InCl3-catalyzed process was further demonstrated with the preparation of the novel butadiene 5-(3,3-bi([1,1'-biphenyl]-4yl)allylidene)-1,3-diethyl-2-thioxodihydropyrimidine-4,6(1H,5H)-dione 3c starting from stoichiometric amounts of 1,3-diethyl-2-thiobarbituric acid 1 and 1,1-di([1,1'-biphenyl]-4yl)prop-2-yn-1-ol 4c (Scheme 5).…”

“…In this context, the pseudoaromatic 2-thioxodihydropyrimidine-4,6(1H,5H)-dione ring of thiobarbituric acid and its N-alkylated derivatives has been extensively employed as an electronwithdrawing moiety in push-pull chromophores [6][7][8][9]. Representative examples are dyes 3a,b, recently described by Dumur and co-workers, featuring p-methoxyphenyl and pdimethylaminophenyl donor groups connected to the barbituric acid skeleton through a 1,3-butadiene chain spacer (Scheme 1), which showed a marked solvatochromic behavior in solution [10,11]. As shown in Scheme 1, compounds 3a,b were obtained by Knoevenagel condensation of commercially available 1,3-diethyl-2-thiobarbituric acid 1 with the corresponding α,β-unsaturated aldehyde 2a,b in refluxing ethanol under basic conditions.…”

“…As shown in Scheme 1, compounds 3a,b were obtained by Knoevenagel condensation of commercially available 1,3-diethyl-2-thiobarbituric acid 1 with the corresponding α,β-unsaturated aldehyde 2a,b in refluxing ethanol under basic conditions. For the preparation of enals 2a,b, Dumur and co-workers followed a classical synthetic behavior in solution [10,11]. As shown in Scheme 1, compounds 3a,b were obtained by Knoevenagel condensation of commercially available 1,3-diethyl-2-thiobarbituric acid 1 with the corresponding α,β-unsaturated aldehyde 2a,b in refluxing ethanol under basic conditions.…”

“…behavior in solution [10,11]. As shown in Scheme 1, compounds 3a,b were obtained by Knoevenagel condensation of commercially available 1,3-diethyl-2-thiobarbituric acid 1 with the corresponding α,β-unsaturated aldehyde 2a,b in refluxing ethanol under basic conditions.…”