Synthesis and Reactivity of 3,4-Dimethyl-4<i>H</i>-1,3,4-thiadiazines

Pfeiffer, W.‐D.; Dilk, Erich; Rossberg, Harald; Langer, Peter

doi:10.1055/s-2003-43342

Cited by 21 publications

(6 citation statements)

References 2 publications

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“…5-Aminopyrazoles 145 were obtained in good yield by heating of 3-methyl-6 H -1,3,4-thiadiazine 146 under reflux of acetic acid ( Scheme 46 ) [ 61 ].…”

Section: The Main Methods Of Access To the Pyrazole Nucleusmentioning

confidence: 99%

Synthesis and Pharmacological Activities of Pyrazole Derivatives: A Review

et al. 2018

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Pyrazole and its derivatives are considered a pharmacologically important active scaffold that possesses almost all types of pharmacological activities. The presence of this nucleus in pharmacological agents of diverse therapeutic categories such as celecoxib, a potent anti-inflammatory, the antipsychotic CDPPB, the anti-obesity drug rimonabant, difenamizole, an analgesic, betazole, a H2-receptor agonist and the antidepressant agent fezolamide have proved the pharmacological potential of the pyrazole moiety. Owing to this diversity in the biological field, this nucleus has attracted the attention of many researchers to study its skeleton chemically and biologically. This review highlights the different synthesis methods and the pharmacological properties of pyrazole derivatives. Studies on the synthesis and biological activity of pyrazole derivatives developed by many scientists around the globe are reported.

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“…5-Aminopyrazoles 145 were obtained in good yield by heating of 3-methyl-6 H -1,3,4-thiadiazine 146 under reflux of acetic acid ( Scheme 46 ) [ 61 ].…”

Section: The Main Methods Of Access To the Pyrazole Nucleusmentioning

confidence: 99%

Synthesis and Pharmacological Activities of Pyrazole Derivatives: A Review

et al. 2018

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“…The cyclization of 1,2-dimethylselenosemicarbazide ( 45 ), containing methyl groups located at both nitrogen atoms of the hydrazine moiety, with phenacylbromides directly afforded 5-imino-1,2-dimethylpyrazoles 46a , b in 54–62% yields (Scheme 25 ). 26 28 Their formation proceeds via unstable 1,3,4-4 H -selenadiazine A which rapidly undergoes deselenation. This can be explained by the fact that in case of deselenation of 1,3,4-6 H -selenadiazines 38 an isomerisation must take place first to generate a 1,3,4-4 H isomer (intermediate A in Scheme 20 ).…”

Section: 34-selenadiazinesmentioning

confidence: 99%

“…A rapid desulfurization has been previously reported for structurally related 1,3,4-4 H -thiadiazines. 28 Since our last paper related to 1,3,4-selenadiazines in 2014, 26 the field remained, to the best of our knowledge, essentially untouched so far.…”

Section: 34-selenadiazinesmentioning

confidence: 99%

Adventures in 1,3-Selenazole Chemistry

Langer

2021

Synlett

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The synthesis of 1,3-selenazoles and related compounds, including 2,4,5-trisubstituted, 2,4-disubstituted, 4,5-disubstituted, 4-substituted 1,3-selenazoles, and parent unsubstituted 1,3-selenazole, is highlighted. Emphasis is also given on 2-benzoyl-1,3-selenazoles which can be functionalized by Knoevenagel reactions or by rearrangements via their corresponding oximes. Syntheses of bis-, tris-, and tetrakis(1,3-selenazoles) are discussed as well. 1,3,4-6H-Selenadiazines are available from selenosemicarbazides and can undergo ring-contraction or deselenation reactions. Most syntheses rely on the application of selenocarboxylic amides, selenourea and related building blocks which are conveniently available by reaction of the corresponding oxygen analogues with P4Se10.1 Introduction2 Selenocarboxylic Amides3 2,4,5-Tri- and 2,4-Disubstituted 1,3-Selenazoles4 Bis(1,3-selenazoles)5 2-Amino-1,3-selenazoles6 2-Unsubstituted 1,3-Selenazoles7 1,3,4-Selenadiazines8 Conclusions

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“…The structure of the thiadiazines was conrmed through desulfurization with acetic acid. 37 Several methods synthesized 1,3,4-thiadiazine, including interactions between thiosemicarbazides and a-halo ketones in different solvents. 38,39 However, Aly et al 40 demonstrated the one-pot synthesis of 2-ylidenehydrazonothiazoles from the reaction of 4-substituted thiosemicarbazides, ketones, and phenacyl bromide, and they proposed that the product was obtained through the formation of the hydrazinylthiazole intermediate, which contradicted the ndings of Pfeiffer et al 41 In light of the previous data on the multitargeted inhibitory action of 1,3,4-thiadiazine derivatives and our ongoing efforts to develop multitargeted anti-cancer agents, 6,7,19,[42][43][44] this investigation focuses on the synthesis of new 1,3,4-thiadiazine derivatives (9a-g, Fig.…”

Section: Introductionmentioning

confidence: 99%