3530-62-9Relevant academic research and scientific papers
A solid-state, solution, and theoretical structural study of kinetic and thermodynamic lithiated derivatives of a simple diazomethane and their reactivities towards aryl isothiocyanates
Armstrong, David R.,Davies, Robert P.,Haigh, Robert,Hendy, Mark A.,Raithby, Paul R.,Snaith, Ronald,Wheatley, Andrew E. H.
, p. 3363 - 3375 (2003)
(Trimethylsilyl)diazomethane (1-H) reacts with nBuLi in THF at elevated temperature to afford (previously reported) 1-Li·3/2 THF. However, reaction in hexane/TMEDA at low temperature affords instead the N-lithiate Me3SiCNNLi·TMEDA (9), which is a novel open pseudo-cubic tetramer in the solid state. Variable-temperature NMR spectroscopy suggests that N-metallated 9, apparently the kinetic product of the reaction, irreversibly rearranges at high temperature in solution to give the thermodynamically preferred C-lithiated isomer. These observations, supported by DFT calculations, influence our understanding of the reactivity of lithiated diazomethanes towards aryl isothiocyanates, suggesting as they do that previously observed product selectivity in these reactions is critically dependent on temperature control exercised during the process. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
Diazole heterocyclic compound and preparation method and application thereof
-
Paragraph 0051; 0052-0055, (2021/02/10)
The invention relates to the technical field of pesticides, in particular to a diazole heterocyclic compound and a preparation method and application thereof. The diazole heterocyclic compound has anexcellent prevention and treatment effect on plant diseases such as plutella xylostella, myzus persicae and tetranychus urticae, and particularly has a remarkable prevention and treatment effect on plutella xylostella. The compound can be used for preparing insecticides in the fields of agriculture, horticulture and the like and developing novel insecticides without cross resistance, and has goodresearch value and market development prospect.
Preparation of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles via chemoselective сyclocondensation of electrophilically activated nitroalkanes to (thio)semicarbazides or thiohydrazides
Aksenov, Alexander V.,Aksenov, Dmitrii A.,Aksenov, Nicolai A.,Arutiunov, Nikolai A.,Kirillov, Nikita K.,Rubin, Michael
, p. 1067 - 1072 (2020/10/02)
[Figure not available: see fulltext.] Unusual reaction proceeding via the electrophilic activation of nitroalkanes in the presence of polyphosphoric acid has been discovered. Subsequent nucleophilic attack with semicarbazides or thiosemicarbazides allows
Heterocyclization of thiocarbonohydrazides: Facile synthesis of 5-unsubstituted-1,3,4-thiadiazoles
Hassan, Alaa A.,Abdel-Latif, Fathy F.,Aziz, Mohamed Abdel,Mostafa, Sara M.,Br?se, Stefan,Nieger, Martin
, p. 1183 - 1186 (2015/09/01)
2-(Hydrazinecarbothioyl)-N-substituted hydrazinecarbothioamides react with 2,3,5,6-tetrachloro-1,4-benzoquinone in high yields in a novel fast and facile method to give 5-unsubstituted-1,3,4-thiadiazole-2-amine derivatives. The synthesized compounds were characterized by spectroscopic methods and confirmed by using X-ray crystallography. A rationale for the formation of the products is presented.
New Cyclizing Reagent for the Synthesis of 1,3,4-Thiadiazoles
Yarovenko, Vladimir N.,Shirokov, Aleksandr V.,Zavarzin, Igor V.,Krupinova, Oksana N.,Ignatenko, Anatolii V.,Krayushkin, Mikhail M.
, p. 17 - 19 (2007/10/03)
A new cyclizing reagent is proposed for the synthesis of 5-unsubstituted 1,3,4-thiadiazoles. The latter are formed in good yields by the reactions of thiohydrazides with diethyl chlorophosphate in DMF.
Studies on Decarboxylation Reactions. Part 7. Kinetic Study of the Decarboxylation of 2-Amino- and 2-Phenylamino-thiazole-5-carboxylic Acids
Noto, Renato,Ciofalo, Maurizio,Buccheri, Francesco,Werber, Guiseppe,Spinelli, Domenico
, p. 349 - 352 (2007/10/02)
The rate constants of the decarboxylation reaction of 2-amino- and 2-phenylamino-thiazole-5-carboxylic acid (3a-b), and, for comparison, of 5-phenylamino-1,3,4-thiadiazole-2-carboxylic acid (2b) have been measured in water over a range of proton activities.The results obtained suggest: (i) compound 2b decarboxylates, in the whole range of proton activity studied, through a unimolecular decarboxyprotonation mechanism characteristic of 1,3,4-oxa- and 1,3,4-thiadiazole derivatives; (ii) in contrast, 3a-b decarboxylate via either a unimolecular decarboxyprotonation or a bimolecular protiodecarboxylation mechanism as a function of proton activity.
NEW METHODS AND REAGENTS IN ORGANIC SYNTHESIS. 53. LITHIUM TRIMETHYLSILYLDIAZOMETHANE: A NEW SYNTHON FOR THE PREPARATION OF 2-AMINO-1,3,4-THIADIAZOLES FROM ISOTHIOCYANATES
Aoyama, Toyohiko,Kabeya, Mototsugu,Fukushima, Atsuko,Shioiri, Takayuki
, p. 2367 - 2370 (2007/10/02)
Lithium trimethylsilyldiazomethane reacts smoothly with isothiocyanates in diethyl ether to give 2-amino-1,3,4-thiadiazoles in good yields.
