Synthesis of 3-amino-5H-pyrrolo[2,3-e]-1,2,4-triazines by Sonogashira/copper(I)-catalyzed heteroannulation

Synthesis, antiviral, DFT and molecular docking studies of some novel 1,2,4-triazine nucleosides as potential bioactive compounds

A novel series of nucleosides with potential antiviral activity have been synthesized and characterized using IR, MS, 1D NMR and 2D NMR data. The antiviral activity of the synthesized compounds was assessed against the Coxsackie B virus and Hepatitis A virus (HAV-10). The results revealed that compound 6 is equipotent to the standard drug Ribavirin against HAV-10. Also, some computational studies, such as the prediction of pharmacokinetic properties, toxicity, and bioactivity, have been done.

Chiral oxazoline ligands with two different six-membered azaheteroaromatic rings – synthesis and application in the Cu-catalyzed nitroaldol reaction

Synthesis and catalytic activity of chiral ligands 5,6-diphenyl-3-{3-[(4S/R)-4-R/Ar-4,5-dihydro-1,3-oxazol-2-yl]pyridin-2-yl}amino-1,2,4-triazines 2 and their analogs 3 possessing an N-oxide function in the pyridine ring are described. The pivotal step in the synthesis of ligands 2 is the Buchwald-Hartwig Pd-catalyzed cross-coupling reaction between 3-bromo-5,6-diphenyl-1,2,4-triazine (7a) and enantiopure 3-(4,5-dihydro-1,3-oxazol-2-yl)pyridin-2-amines 6a–d. Aromatic nucleophilic substitution of chlorine in 3-chloro-5,6-diphenyl-1,2,4-triazine (7b) with 3-(4,5-dihydro-1,3-oxazol-2-yl)pyridin-2-amine 1-oxides 12 was investigated as the key reaction in the synthesis of ligands 3. Two undesired derivatives 13 or 14, resulting from unexpected reactions of 3, were isolated depending on reaction conditions. Compounds 2 and 3 as well as the side products 13 and 14 were screened as chiral ligands in the copper catalyzed enatioselective nitroaldol reaction.

Glycosylation, sugar hydrazones, and antimicrobial evaluation of some 6-substituted-1,2,4-triazines

Hydrazinolysis of 4-amino-6-[2-(4-methoxyphenyl)vinyl]-3-thioxo-3,4-dihydro-2H-[1,2,4] triazin-5-one (1) gave the corresponding hydrazino derivatives (2) Cyclocondensation of (2) with carbon disulfide furnished 8-amino-6-[2-(4-methoxyphenyl)vinyl]-3-thioxo-2,8-dihydro-3H-[1,2,4]triazolo[4,3-b][1,2,4]triazin-7-one (3) which was treated with 2,3,4,6- tetra-O-acetyl-alpha-D-glucopyranosyl bromide (4) in pyridine to give the corresponding N-glucosyl derivative 5, which deblocked to give 8. Compound 2 was reacted with isatin 9 and/or isatoic anhydride 10 to afford 11 and 12. Treatment of 11 and 12 with (4) in pyridine gave the corresponding mono glucosyl derivatives 13 and 14, which were deblocked by ammonia and afforded 15 and 16. Condensation of 2 with aldoses afforded the corresponding cyclic products 17a-f and with D-fructose furnished 18. Acetylation of 17b, d afforded the corresponding polyacetyl derivatives 19b,d. Compound 2 condensed with some aromatic aldehydes in boiling methanol and gave 20a-f. The newly synthesized compounds were tested as antimicrobial agents.