Double-headed Acyclo C-Nucleoside Analogues. Functionalized 1,2-bis-(1,2,4-Triazol-3-yl)ethane-1,2-diol

Abstract

Reaction of L-tartaric acid with thiocarbohydcrazide afforded (1R, 2S)-1,2-bis(4-amino-5-mercapto-1,2,4-triazol-3-yl)-ethane-1,2-diol (3). The functional groups in 3 allowed the construction of fused heterocycles on the 1,2,4-triazole rings, mainly of the 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine type as in 4, 5, 7, 10, 13 and 1,2,4-triazolo[3,4-b][1,3,4]thiadiazole type as in 14.

Recent Progress in the Synthetic Routes to Triazolothiadiazines

“…111 Cycloaddition of (1R,2S)-1,2-bis(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)ethane-1,2-diol 8 with phenacyl bromide under basic conditions afforded the triazolothiadiazine derivative 9 in 87% yield (Scheme 4). 112 Bis(5,6-dihydro-s-triazolo [3,4-b]thiadiazines) 11 were prepared in 58-95% yields by reaction of bis(α-bromoketones) 10 with 4-amino-3-mercapto-1,2,4-triazole derivatives 1 in anhydrous ethanol (Scheme 5 Treatment of the aminothiol 1 with oxalyl chloride in dry benzene afforded the corresponding triazolothiadiazine-6,7-dione 16 (Scheme 8). 87 Downloaded by [134.117.10.200] at 09: 15 28 November 2014 …”

Synthesis and Characterization of Mono‐ and Bicycle Heterocyclic Derivatives Containing 1, 2,4‐Triazole, 1,3,4‐Thiadiazine and 1,3‐Thiazole Rings

“…The compound 3 was synthesized by using the reported procedure 16 . [1,2,4]triazolo [3,4-b] [1,3,4] [1,2,4]triazolo [3,4-…”

“…in pyridine gave 1,2-bis (4-amino-5mercaprto-4H-1,2,4-triazol-3-yl)-ethane-1,2-diol (3) and 1,2-bis(5-mercapto-4H-1,2,4-triazol-3-yl)-ethane-1,2-diol (7), respectively.The reaction proceeds through a nucnucleophilic attack of N-1 of the thiocarbohydrazide or thiosemicarbazide on the carbonyl carbon, then by futher nucleophilic attack of the N-3 to the carbonyl carbon and subsequent dehydration of the cyclized intermediate to give 316 and 7 (Scheme 1, 2). Reaction of compound 3 with DMAD (dimethylacetylendicarboxylate) and DEAD (diethylacetylendicarboxylate) afforded 1,2-bis(7-[(z)-methoxycarbonylmethylen]-5, 6-dihydro-5H-6-one-[1,2,4]triazolo[3,4-b] [1,3,4] thiadiazin-3-yl)-ethan-1,2-diol 4 and 1,2-bis (7-[(z)-ethoxycarbonylmethylen]-5,6-dihydro-5H-6-one-[1,2,4]triazolo[3,4-b][…”

Synthesis of spiro[indole-3,3′-[1,3,4]thiadiazino[3,2-a]benzimidazoles] and spiro[indole-3,6′-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines]

“…13 Earlier, we have developed a method for the synthesis of 6,7 dihydro 5H 1,2,4 triazolo [3,4 b] [1,3,4]thiadi azines, 14, 15 3,4 dihydro 2H imidazo [2,1 b] [1,3,4]thiadi azines, and spirocyclic imidazo [2,1 b] [1,3,4]thiadiazines 16 by intramolecular cyclization of S alkyl derivatives of N triazolyl and N imidazolyl imines. The goal of the present work was to extend the synthetic scope of the proposed method through the use of 1 amino 1H benz imidazole 2 thiol and 4 amino 5 R 4H 1,2,4 triazole 3 thiols as the starting reagents and to obtain novel spiro cyclic fused tetrahydrothiadiazine systems.…”