- Synthesis of 2-amino-substituted-1,3,4-thiadiazoles via 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) mediated intramolecular C-S bond formation in thiosemicarbazones
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An effective oxidative intramolecular cyclization (C-S bond formation) of thiosemicarbazones using 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) has been developed to afford a diverse array of 2-amino-substituted-1,3,4-thiadiazoles. The attractive featu
- Singh, Sarangthem Joychandra,Rajamanickam, Suresh,Gogoi, Anupal,Patel, Bhisma K.
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- Synthesis of novel thiazole and pyrrolothiadiazine derivatives from aldehyde thiosemicarbazones
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Substituted thiosemicarbazones 7a-e reacted with ethenetetracarbonitrile (TCNE) in ethyl acetate with formation of 5-amino-3-(substituted benzylidene - amino)- 2-phenylimino-2,3-dihydrothiazole-4-carbonitrile 8a-e 2-amino-6-phenyl-imino-1, 6-dihydropyrrol
- Gomaa, Mohsen A.-M.,Hassan, Alaa A.,Shehatta, Hamdy S.
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- An efficient one-pot procedure for the preparation of 1,3,4-thiadiazoles in ionic liquid [Bmim]BF4 as dual solvent and catalyst
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The one-pot three component condensation of hydrazine hydrate with substituted phenylisothiocyanates followed by the addition of substituted benzaldehydes in the presence of ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4)
- Rostamizadeh, Shahnaz,Aryan, Reza,Ghaieni, Hamid R.,Amani, Ali M.
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- Diazole heterocyclic compound and preparation method and application thereof
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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.
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Paragraph 0051; 0052-0055; 0074-0075
(2021/02/10)
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- PhI-Catalyzed Intramolecular Oxidative Coupling Toward Synthesis of 2-Amino-1,3,4-Thiadizoles
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A highly efficient method for the synthesis of thiadiazole derivatives via intramolecular oxidative coupling of thiosemicarbazide, using the in situ generated hypervalent iodine(III) reagents is developed. The protocol can be carried out smoothly and provides a variety of thiadiazole derivatives in moderate to excellent yields. Graphical Abstract: A highly efficient method for the synthesis of thiadiazole derivatives via PhI-catalyzed intramolecular oxidative coupling of thiosemicarbazide has been developed.
- Han, Yingzhi,Sun, Yadong,Abdukader, Ablimit,Liu, Bifu,Wang, Duozhi
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p. 3486 - 3491
(2018/09/27)
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- Vibrational and quantum chemical investigation of cyclization of thiosemicarbazide group in 1-benzoyl-4-phenyl-3-thiosemicarbazide
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1-Benzoyl-4-phenyl-3-thiosemicarbazide (H3bpt) was treated with acid - base in one sequence and base - acid in other sequence, both of which lead to ring formation of thiosemicarbazide group, giving N-phenyl-5-phenyl-1,3, 4-thiadiazol-2-amine (Hppta) in the first case and 4,5-diphenyl-2,4-dihydro-1,2, 4-triazole-3-thione (Hdptt) in the second case. The primary (H3bpt) as well as the resulting compounds (Hppta & Hdptt) has been characterized by elemental analyses, NMR, FTIR and Raman spectroscopic techniques. The quantum chemical calculations of the compounds are performed using DFT/B3LYP/6311G(d,p) method for geometry optimizations and also for prediction of the molecular properties. The cyclization is confirmed by disappearance of many bands belonging to the open chain subgroups of H3bpt such as; NH stretching, NH bending, CN stretching, NH puckering, CO stretching etc. The ring formation of 1-benzoyl-4-phenyl-3-thiosemicarbazide (H3bpt) has been further confirmed by the appearance of many bands belonging to the closed ring of thiosemicarbazide in the resulting compounds Hppta and Hdptt.
- Gautam, Priyanka,Prakash, Om,Dani,Singh,Singh, Ranjan K.
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p. 278 - 287
(2014/06/10)
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- Regioselective synthesis of 2-amino-substituted 1,3,4-oxadiazole and 1,3,4-thiadiazole derivatives via reagent-based cyclization of thiosemicarbazide intermediate
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A regioselective, reagent-based method for the cyclization reaction of 2-amino-1,3,4-oxadiazole and 2-amino-1,3,4-thiadiazole core skeletons is described. The thiosemicarbazide intermediate 3 was reacted with EDC·HCl in DMSO or p-TsCl, triethylamine in N-
- Yang, Seung-Ju,Lee, Seok-Hyeong,Kwak, Hyun-Jung,Gong, Young-Dae
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p. 438 - 444
(2013/04/10)
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- Synthesis of some 1,3,4-thiadiazole derivatives as inhibitors of Entamoeba histolytica
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In the quest for potent anti-amoebic agents, some 1,3,4-thiadiazole derivatives were synthesized and characterized by spectral data. The purity of the compounds was confirmed by elemental analysis. All the compounds were screened in vitro against HM1:IMSS strain of Entamoeba histolytica by microdilution method. The results revealed that compounds 1 (IC50 = 0.670 μM), 3 (IC50 = 1.60 μM) and 8 (IC50 = 0.522 μM) had much better anti-amoebic activity than the reference drug metronidazole (IC50 = 1.80 μM). Further, cytotoxicity of the compounds having IC50 value less than metronidazole was assessed by MTT assay on human breast cancer MCF-7 cell line and all the compounds were found low cytotoxic in the concentration range of 2.5-250 μM. Preliminary results indicate that these three compounds (1, 3 and 8) may be subjected to further investigations and it may be hoped that the present study will stimulate efforts towards the development of novel effective anti-amoebic agents.
- Siddiqui, Shadab Miyan,Salahuddin, Attar,Azam, Amir
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p. 1305 - 1312
(2013/04/10)
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- FeCl3-promoted synthesis of 1,3,4-thiadiazoles under combined microwave and ultrasound irradiation in water
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An eco-friendly and efficient synthesis of substituted 1,3,4-thiadiazole derivatives has been developed. This aqueous heterogeneous approach proceeds smoothly and quickly under combined microwave and ultrasound irradiation in the presence of FeCl3.
- Feng, Huangdi,Ying, Xili,Peng, Yanqing,Van Der Eycken, Erik V.,Liu, Chuanduo,Zhao, Shanshan,Song, Gonghua
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p. 681 - 686
(2013/07/26)
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- Efficient synthesis of 1,3,4-thiadiazoles using hydrogen bond donor (thio)urea derivatives as organocatalysts
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(Chemical Equation Presented) A simple and efficient procedure for the synthesis of 1,3,4-thiadiazoles has been achieved using thiourea as organocatalyst. In this study, the steric and electronic effects using structurally different derivatives of urea and thiourea in different solvents were evaluated. The best yields and the rate of the reactions were obtained using 30 mol % of thiourea as catalyst in acetonitrile at room temperature. The molecular structures of the products were established by 1H and 13C NMR spectral data.
- Rostamizadeh, Shahnaz,Aryan, Reza,Ghaieni, Hamid Reza,Amani, Ali Mohammad
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experimental part
p. 616 - 623
(2010/07/18)
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- Dithiocarbamate as an efficient intermediate for the synthesis of 2-amino-1,3,4-thiadiazoles in water
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A new and facile protocol for the synthesis of 2-amino-1,3,4-thiadiazoles in water is described. Reaction of acid hydrazides with easily prepared dithiocarbamates gives the corresponding thiadiazoles in moderate to excellent yields. 2-Amino-1,3,4-oxadiazoles were not observed as side products using this procedure.
- Aryanasab, Fezzeh,Halimehjani, Azim Ziyaei,Saidi, Mohammad R.
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supporting information; experimental part
p. 790 - 792
(2010/03/24)
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- Indenoxadiazine, indenopyrazole and spiro triazole derivatives from (substituted ylidene)-N-phenylhydrazine carbothioamides
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In a multistep reaction, indeno[2,1-e][1,3,4]oxadiazine-9-one, oxoindeno[1,2-c]- pyrazolecarbothioamide, (thioxo-1,2,4-triazaspiro[4.5] decadienylidene)malononitrile and spiro-(fluorine-9,3′-[1,2,4]triazoline)- 5′-thione derivatives have been formed from a series of (substituted ylidene)-N-phenylhydrazinecarbothioamides 1a-e with (1,3-dioxo-2,3-dihydro-1H- inden-2-ylidene)propanedinitrile, 7,7′,8,8′-tetracyanoquinodimethane and (2,4,7-trinitro-9H-fluoren-9-ylidene)propanedinitrile in aerated pyridine. Rationales of these conversions involving the nucleophilic reactions, condensation, dehydrogenation and oxidation are presented.
- Hassan, Alaa A.,Shehata, Hamdy S.
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p. 629 - 635
(2008/09/19)
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- New access to pyrazole, oxa(thia)diazole and oxadiazine derivatives
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1,4-Disubstituted thiosemicarbazides 1b-f reacted with ethenetetracarbonitrile (5) in dimethylformamide with formation of 2-substituted 5-phenyl-1,3,4-thiadiazoles 2a-f and 2-substituted 5-phenyl-1,3,4-oxadiazoles 4a-f. Upon addition of 5 to 1c-e in chlorobenzene, 3-amino-2-benzoyl-4,5,5- tricyano-2,5-dihydro-1H-pyrazole- 1-[N-(4-tricyanovinyl)phenyl]carbothioamide (12), 5-benzylamino-, and 5-allylamino-4-benzoyl-2,3-dihydro-[1,3,4]thiadiazol- 2,2-dicarbonitrile (13a,b) and 5-amino-1-benzoylpyrazole-3,4-dicarbonitrile (14) as well as 2-phenyl-4H-[1,3,4]-oxadiazine-5,6-dicarbonitrile (15) were formed. Rationales for the role of the solvent and the conversions observed are presented.
- Hassan, Alaa A.,El-Shaieb, Kamal M.,Shaker, Raafat M.,Doepp, Dietrich
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- 1,3,4-Thiadiazole derivatives. Synthesis, structure elucidation, and structure-antituberculosis activity relationship investigation
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A series of 2,5-disubstituted-1,3,4-thiadiazoles were synthesized, the compounds structures were elucidated and screened for the antituberculosis activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system. Among the tested compounds, 2-phenylamino-5-(4-fluorophenyl) -1,3,4-thiadiazole 22 showed the highest inhibitory activity. The relationships between the structures of compounds and their antituberculosis activity were investigated by the Electronic-Topological Method (ETM) and feed forward neural networks (FFNNs) trained with the back-propagation algorithm. As a result of the approach, a system of pharmacophores and anti-pharmacophores has been found that effectively separates compounds of the examination set into groups of active and inactive compounds. The system can be applied to the screening and design of new active compounds possessing skeletons similar to those used in the present study.
- Oru?, El?in E.,Rollas, Sevim,Kandemirli, Fatma,Shvets, Nathaly,Dimoglo, Anatholy S.
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p. 6760 - 6767
(2007/10/03)
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- The reactions of cyclization of thiosemicarbazide derivatives to 1,2,4-triazole or 1,3,4-thiadiazole system
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In the reaction of hydrazide of formic, nicotinic and benzoic acid with isothiocyanates were obtained the respective thiosemicarbazide derivatives [I-XII]. Further cyclization with 2% NaOH solution led to formation of derivatives Δ2-1,2,4-triaz
- Dobosz, Maria,Pitucha, Monika,Wujec, Monika
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- Dihalogentriphenylphosphoranes in Heterocyclic Synthesis; 15. A Simple One-Pot-Procedure for the Generation of Nitrilimines with the Aid of Dihalogentriphenylphosphoranes: 1,3-Dipolar Cycloadditions and 1,5-Electrocyclizations
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A simple and versatile one-pot procedure for the in situ generation of nitrilimines from N-acyl hydrazines is described. 1,3-Dipolar cycloadditions and 1,5-electrocyclic ring closures are carried out.Unsymmetrically substituted dipolarophiles show typical
- Wamhoff, Heinrich,Zahran, Magdy
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p. 876 - 879
(2007/10/02)
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- REACTION OF PHENYLTRICHLOROMETHANE WITH SEMICARBAZIDE AND THIOSEMICARBAZIDE DERIVATIVES
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Phenyltrichloromethane 1 reacts with 4-phenylsemicarbazide and yields ethyl N-phenylcarbamoylmethane hydrazonate 10.Thermolysis of 10 yields 3,4-diphenyl-1H-1,2,4-triazolin-5-one 9a, identified by its alternate synthesis from the amidrazone 14 and dipheny
- Hassaneen, Hamdi M.,Shetta, Abdelfattah H.,Elwan, Nehal M.,Shawali, Ahmad S.
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p. 1477 - 1482
(2007/10/02)
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