Cyclocondensation Reations of 3‐Amino‐1,2,4‐triazole with 3‐(Benzylidene)‐6‐fluoro‐thiochroman‐4‐ones to Tetracyclically Fused Dihydropyrimidines and Pyrimidines

Abstract

The effects of reaction temperature, solvents, reaction time and 7-aryl on the cyclocondensation reactions of 3-amino-1,2,4-triazole with 3-(benzylidene)-6-fluorothiochroman-4-ones were studied. The experimental results show that except tetracyclic fused dihydropyrimidines and pyrimidines were produced simultaneously in the cyclocondensation reactions, the dihydropyrimidines could be directly converted into pyrimidines without any dehydrogenizing reagent under high temperature. The structures of the new synthesized compounds were confirmed by 1 H NMR, MS spectra, elemental analysis, and X-ray single crystallography. The cyclocondensation mechanism for producing the tetracyclically fused dihydropyrimidines and pyrimidines was discussed.

Novel one‐pot synthesis of imidazo[2,1‐b] [1, 2, 4]‐Triazoles, 1,2,4‐Triazolo iminoindoline‐2‐ones, and their in‐vitro antibacterial activity, B‐DNA study

“…1,2,4-Triazole moiety has received special attention for the development of various heterocyclic systems [3], while the 4H-1,2,4-Triazole moiety is having free amino functional group at the third position of triazole ring, which enhances the possibility to develop variety of either fused or unfused five-and six-membered heterocyclic compounds such as imidazoles, pyrimidines, thiazoles, and pyridines [4][5][6][7][8][9][10][11]. Furthermore, the primary amines are helpful for the synthesis of Schiff bases and Mannich bases, which are significant intermediates in organic synthesis [12].…”