Synthesis and fluorescence of dihydro-[1,2,4]triazolo[4,3-a]pyridin-2-ium-carboxylates: An experimental and TD-DFT comparative study

Application of Safirinium N-Hydroxysuccinimide Esters to Derivatization of Peptides for High-Resolution Mass Spectrometry, Tandem Mass Spectrometry, and Fluorescent Labeling of Bacterial Cells

“…A panel of Safirinium derivatives bearing diverse alkyl groups within the triazolium moiety ( Scheme 1 ) have been synthesized according to our previously reported procedures [ 42 , 43 ]. Hence, the corresponding isoxazolones 1 and 2 were subjected to tandem Mannich–electrophilic amination reactions with formaldehyde and various secondary amines, such as diethylamine ( a ), dioctylamine ( b ), and pyrrolidine ( c ), to give Safirinium P (pyridine) and Q (quinoline) products 3′ and 4′ , respectively.…”

“…Samples for lyophilization were frozen in liquid nitrogen and lyophilized on a Speedvac or Freeze-dryer from Labconto (Kansas City, MO, USA). The absorption and emission spectra of Safirinium dyes and their derivatives have been presented previously [ 42 , 43 , 48 ].…”

“…Recently, we have reported the synthesis of fluorescent compounds based on 1,2,4-triazolo[4,3- a ]pyridin-2-ium carboxylate system named Safirinium dyes ( Figure 1 ) [ 42 , 43 ]. The novel derivatives demonstrate narrow and tunable absorption and emission bands, high-fluorescence quantum yields, relatively large Stokes shifts, and photostability.…”

Lipophilicity Determination of Antifungal Isoxazolo[3,4-b]pyridin-3(1H)-ones and Their N1-Substituted Derivatives with Chromatographic and Computational Methods

“…The synthesis of the investigated compounds is previously reported [15,21,22]. Briefly, compound 14 was obtained via condensation of N -hydroxy-3-(hydroxyamino)-3-iminopropanamide with acetylacetone in the presence of piperidne [15], while compounds 1 and 23 were synthesized through multi-step procedure from aniline and 2,5-dimethoxyaniline, respectively [21,36]. Derivatives 2–5 and 6–13 , 15–18 were synthesized by acylation, alkylation or sulfonation reactions of compounds 1 [15,22] and 14 [21], respectively, while compounds 19–22 , 24–26 were obtained through methylation of the corresponding isoxazolones [21].…”

2,2′-((1,4-Dimethoxy-1,4-dioxobutane-2,3-diylidene)bis(azanylylidene))bis(quinoline-3-carboxylic acid)

“…All reagents and solvents were purchased from commercial sources (Acros Organics, Geel, Belgium; Alfa-Aesar, Haverhill, MA, USA; or Sigma-Aldrich, Saint Louis, MO, USA) and used without further purification. Isoxazolo [3,4-b]quinolin-3(1H)-one 2 was obtained according to the known procedure [40,41]. Analytical TLC was performed on silica gel Merck 60 F254 plates (0.25 mm) with UV light visualization.…”