Synthesen stickstoffhaltiger Heterocyclen, XLI. Über 1.2.4‐Triazine, VI. Reaktionen von 4‐Amino‐3‐methylmercapto‐5‐oxo‐4.5‐dihydro‐1.2.4‐triazinen

Abstract

Die Substitution der Methylmercaptogruppe in 1.2.4‐Triazinen durch Hydroxylamin und anschließende Umsetzung mit Ameisensäure, Schwefelkohlenstoff oder Acetanhydrid sowie Substitution durch Malonsäure‐dinitril ermöglicht die Synthese von einigen neuen bi‐ und triheterocyclischen Ringsystemen.

WITHDRAWN: Reactivity of 3-hydrazono-1, 2, 4-triazines towards various strong electrophiles - Synthesis of heteropolycyclic nitrogen systems Targets a review

“…Dornow et al, (Dornow & Pietsch 1967) reported that behavior of 3-hydrazino-5,6-diphenyl -1,2,4-triazine (1) towards a bis-thiocarbonyl as carbondisulfide in refluxing dry pyridine afforded 3-thioxo-2H-6,7-diphenyl-1,2,4-triazolo [4,3-b] [1,2,4] triazine dicyanomethyl-6,7-diphenyl-1,2,4-triazolo[4,3-b] [1,2,4] triazine (87). …”

Synthesis and properties of N-aminoazolinethiones and N-aminoazinethiones 2. Reactions

“…Displacement of the methylthio group is possible in neutral heterocycles. For example, 4-amino-3-methylthio-l,3,4-triazines CXCIV reacted with hydroxylamine [155], dicarbodiimides [127,156], malonodinitrile [155], carbon disulfide [72,157] or underwent cyclodimerization [155]. The reaction of the aminothiones CXCV with hydrazine hydrate is an example of nucleophilic displacement of an unsubstituted mercapto group [158].…”

Synthetic approaches to 1,2,4-triazolo[5,1-c][1,2,4]triazin-7-ones as basic heterocyclic structures of the antiviral drug Riamilovir (“Triazavirin®”) active against SARS-CoV-2 (COVID-19)

“…As a result, 6-methyl-and 6-phenyl-1,2,4-triazolo[5,1-c]-1,2,4-triazin-7(4H)-ones 54 were obtained. [45][46][47] The aza-Wittig reaction of 1,2,4-triazinone hydrazone 55 containing an iminophosphorane fragment with aliphatic isocyanates (Scheme 14) was reported as another example for the synthesis of 1,2,4-triazolo[5,1-c]-1,2,4-triazinones according to the scheme [1 + 4]. 2-Alkylamino-3-methyl-1,2,4-triazolo[5,1-c]-1,2,4-triazin-7(3Н)-ones 56 were obtained in good yields.…”