A Novel Synthesis of 1,2,4-Triazolopteridines

Abstract

Reaction of 1,2-dihydro-2-thioxopteridin-4(3H)-one, 6,7-dimethyl-1,2-dihydro-2-thioxopteridin-4(3H)-one and 6,7-diphenyl-1,2-dihydro-2-thioxopteridin- 4(3H)-one with hydrazonoyl halides affords the title compounds in good yields.

A Convenient Regioselective Synthesis of Novel 1,4‐Phenylenemethylene‐6,6′‐bis‐([1,2,4‐triazolo]‐[4,3‐b][1,2,4]‐triazin‐7(1H)‐ones)

“…The solid that precipitated was collected to give 6,6 0 -(1,4-phenylenebis(methylene))-bis(3 (methylthio)-1,2,4-triazin-5(4H)-one) 8. This compound was obtained as pale yellow crystals, yield (16.87 g, 87%), mp above 350°C (DMF); IR: NH 3307, C═O 1685 cm À1 ; 1 Synthesis of (1,4-phenylenebis(methylene))bis(5-oxo-4phenyl-4,5-dihydro-1,2,4-triazine-6,3-diyl)bis(N-aryl-2oxopropanehydrazonothioate) derivatives (9). To a mixture of hydrazonoyl halides (6.0 mmol) and 6,6 0 -(1,4phenylenebis(methylene))bis(4-phenyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one) 5 (1.5 g, 3.0 mmol) in chloroform (20 mL), triethylamine (0.6 mL, 6.0 mmol) was added at room temperature.…”

“…Also, they showed a broad spectrum against leukemic cell lines and a wide range of cancer cells [3][4][5][6]. In continuation to our previous research directed toward reaction of hydrazonoyl halides with various heterocyclic thione to synthesize triazolo [1,2,4]triazine [7], triazolo[4,3-a]quinazoline [8], triazolopetridine [9], pyridine [2,3-d]pyrimidine [10], triazolo [4,3-a]pyrimidine [11], and spiroheterocycles [12,13], it was thought interesting to study reactions of such halides with the new 6,6 0 -(1,4-phenylenedimethylene) bis-(3-thioxo-1,2,4-triazin-5(1H)-ones) 4(5) (Scheme 1).…”

A novel one-pot three-components reaction: synthesis of indeno[2',1':5,6]pyrido[2,3:4'',5'']pyrimido[2'',1''-c]triazole-5,7-dione. A new ring system

“…These can result either from initial formation of 14 or isomeric 15 and followed by cyclization via elimination of hydrogen sulphide. However, a possible initial [3+2] cycloaddition at the thiocarbonyl group and subsequent rearrangement afforded products 12 following well accepted mechanism initially suggested by Hassaneen et al [11][12][13][14][15] (Scheme 3). The assigned structure for compounds 12 was further confirmed by chemical transformation.…”

Synthesis and Antimicrobial Activity of Bis-[4-methoxy-3-(6-aryl-7H-[1,2,4]triazolo[3,4-b][1,3,4]-thiadiazin-3-yl)phenyl]methanes and Bis-[(triazolo[3,4-b]thiadiazipin-3-yl)phenyl]methanes

“…11 It is interesting to use 1,2,4-triazole derivatives as precusors in the synthesis of some important biologically active heterocycles, [12][13][14][15] which constitute an important class of organic compounds with diverse biological activities, including antiparasitic, analgesic, antibacterial and anti-inflammatory activities. [16][17][18][19][20][21] In addition, it was reported that triazole fused with a six-membered ring system is also found to possess diverse applications in the field of medicine. [22][23][24][25] The commonly known systems are triazolo-pyridines, 26 triazolo-pyridazines, 27 triazolo-pyrimidines, 28 triazolo-triazines, 29 triazolo-pyrazines, 30 triazolo-triazenes, 31 a few monomeric triazolo-thiadiazine, 31 and triazolo-thiadiazepines, 32 although there are not many triazoles fused to thiadiazines and thiadiazepines, there is a number of them that are incorporated into a wide variety of therapeutically important compounds possessing a broad spectrum of biological activities.…”