Synthesis of partially hydrogenated 1,3,5-thiadiazines by Mannich reaction

Synthesis of Schiff and Mannich bases of news-triazole derivatives and their potential applications for removal of heavy metals from aqueous solution and as antimicrobial agents

“…45 Moreover, one of the most concise and effective approaches to the preparation of the biologically active striazolo-1,3,5-thiadiazines is based on the double Mannich-type condensation of 2-mercaptoazole or -azine derivatives with primary amines and an excess of formaldehyde. 46 Although several pollutants have been registered as contaminants of emerging concern in water, no studies have been reported for the applications of triazole Mannich base compounds in water treatment processes. When metal and heavy metal ions exist in water above the maximum contaminated levels, environmental problems can result, according to the World Health Organization (WHO) and the U.S. Environmental Protection Agency (EPA).…”

Synthesis of 4-(1,3,5-Thiadiazinan-2-ylidene)-2-(3,4- dihydro-2H-1,3,5-thiadiazin-6-yl)pent-2-enedinitriles

“…1,3,5-Thiadiazines belong to an important class of heterocyclic compounds. The synthesis of 1,3,5-thiadiazines is successfully realized on the basis of Mannich-type aminomethylation [10][11][12][13]. 1,3,5-Thiadiazines are also of interest due a wide range of biological activity and practically important properties [12,14,15];…”

“…among the most important representatives of this class, the fungicide Dazomet and the highly effective insecticide Buprofezin, are worth mentioning ( Figure 1). Our interest in the synthesis of condensed 1,3,5-thiadiazines through the aminomethylation of cyclic thioamides [12,[16][17][18] prompted us to study the behavior of new cyclic cyanothioacetamide derivatives in the reaction with primary amines and formaldehyde. Triethylammonium 3-cyano-5-ethoxycarbonyl-6-oxo-1H-pyridine-2-thiolate 1 was chosen as a starting compound.…”

“…Due to the presence of two nucleophilic centers (endocyclic nitrogen atom and sulfur atom), thiolate 1 seemed to be a promising substrate for aminomethylation leading to pyrido [2,1-b] [1,3,5]thiadiazines with potential biological activity [12,16]. In the aminomethylation reactions, the nature of the trialkylammonium cation, as a rule, does not affect significantly the yields and the direction of a process.…”

The Mannich-Type Synthesis of Macroheterocycles with Pyrido[2,1-b][1,3,5]thiadiazine Unit

“…Москва, Российская Федерация 1,3,5-Thiadiazines have attracted great attention due to a wide spectrum of biological activity (for reviews on the 1,3,5-thiadiazine chemistry, see [1][2][3][4] ). Recently we have found that thiolate 1 readily reacts with excess of formaldehyde HCHO and primary amines in boiling DMF to give 7,7'-bis(pyrido [2,1-b] [1,3,5]thiadiazinyl)methanes 2 [5] (Scheme 1).…”