Andranik Petrosyan

Synthesis of Fluorinated Purine and 1-Deazapurine Glycosides as Potential Inhibitors of Adenosine Deaminase

The synthesis of 2- and 6-trifluoromethylated purines and 1-deazapurines was performed by formal [3 + 3]-cyclization reactions of 5-aminoimidazoles with a set of trifluoromethyl-substituted 1,3-CCC- and 1,3-CNC-dielectrophiles. The corresponding fluorinated nucleosides were synthesized by glycosylation of 9-unsubstituted purines and 1-deazapurines with peracetylated β-ribose, β-glucose, and rhamnose and subsequent deprotection. These scaffolds can be considered as potential inhibitors of adenosine deaminase (ADA) and inosine monophosphate dehydrogenase (IMPDH) enzymes.

Synthesis of 2,5‐Diarylpyrroles by Ligand‐Free Palladium‐Catalyzed CH Activation of Pyrroles in Ionic Liquids

The palladium‐catalyzed CH activation and arylation of N‐methylpyrrole and N‐phenylpyrrole allowed a convenient synthesis of diarylpyrroles. The reactions were performed by using tetrabutylammonium acetate as an ionic solvent, which allowed for the application of a ligand‐free catalytic system by using simple palladium salts or polyvinylpyrrolidone‐stabilized palladium nanoparticles as the catalyst.

Synthesis and properties of thiazolo[2,3-c][1,2,4]triazoles

Effects of different factors on the electrophilic halocyclization of 3-substituted 4-allyl(or 2-methylprop-2-en-1-yl)-1,2,4-triazole-5(1H)-thiones were studied. The only reaction products were thiazolo[2,3-c]-[1,2,4]triazoles. Some their transformations afforded new derivatives that can find application in pharmacology.

Synthesis of optically pure ( S )-2-amino-5-arylpent-4-ynoic acids by Sonogashira reactions and their potential use as highly selective potent inhibitors of aldose reductase

A new and convenient synthesis of optically pure (S)-2-amino-5-[aryl]pent-4-ynoic acids (alkynylated amino acids) is reported. (S)-2-Aminopent-4-ynoic acid-Ni-(S)-BPB was prepared and then functionalized via Sonogashira cross-coupling reactions to give (S)-2-amino-5-[aryl]pent-4-ynoic acid-Ni-(S)-BPB. The reaction conditions for the cross-coupling reaction were optimized and twelve derivatives were synthesized. Afterwards the Ni-complexes were cleaved to obtain the free (S)-2-amino-5-[aryl]pent-4-ynoic acids with excellent optical purity. The prepared (S)-2-amino-5-[aryl]pent-4-ynoic acids were tested for biological activity and selectively showed high inhibitory activity against aldose reductase (ALR2) over ALR1. Molecular docking studies have also been carried out to identify the putative binding mode of the compounds in these enzymes.

Large Stokes Shift Ionic Liquid Dye

We have incorporated the dye N-methyl-6-oxyquinolone [6MQz] in its protonated form as a cation into an ionic liquid (IL) and thus to synthesize an IL dye. The IL dye N-methyl-6-hydroxyquinolinium bis(trifluoromethylsulfonyl) imide [6MQc][NTf2 ] was characterized by NMR, ATR IR spectroscopy and X-ray crystallography. The fluorescence of the IL dye has a large Stokes shift of Δλ=116 nm and a quantum yield of φF =0.56 in acetonitrile. Characteristic solvent dependent shifts can be detected in the emission spectra. In other ILs, acetonitrile and THF we observe a bathochromic shift of up to 28 nm compared to the pure IL dye at 467 nm. For stronger polar solvents the fluorescence signals are strongly red-shifted to 650 nm indicating proton transfer to the solvent molecules in the excited state. This underlines the importance of the IL building block [MQc]+ as photo acid.

Synthesis of aminomethyl derivatives of 5-substituted-3-(prop-2-ynyl)dihydrofuran-2(3H)-ones

Abstract An easy approach for the synthesis of various 5-substituted-3-(prop-2-ynyl)dihydrofuran-2(3H)-ones is described. As a method of choice, Mannich aminomethylation of terminal alkynes is adopted. The reaction works well with acyclic and cyclic secondary amines and provides the desired products, with good to very good yields.