66357-40-2Relevant academic research and scientific papers
Synthesis of highly functionalized thiazolo[3,2-: A] pyridine derivatives via a five-component cascade reaction based on nitroketene N, S-acetal
Bayat, Mohammad,Hosseini, Hajar,Razavi, Zohreh Sahhaf
, p. 31039 - 31048 (2020)
A highly efficient and straightforward synthesis of N-fused heterocyclic compounds including 5-amino-7-(aryl)-8-nitro-N'-(1-(aryl)ethylidene)-3,7-dihydro-2H-thiazolo[3,2-a]pyridine-6-carbohydrazide derivatives is successfully achieved via a five-component cascade reaction utilizing cyanoacetohydrazide, various acetophenones, aromatic aldehydes, 1,1-bis(methylthio)-2-nitroethylene and cysteamine hydrochloride in ethanol at reflux conditions. The new approach involves domino N,S-acetal formation, Knoevenagel condensation, Michael reaction, imine-enamine tautomerization and N-cyclization sequences. The prominent advantages of this protocol include: facility of operation, available and economical starting materials, no need for toxic solvents, high yields and tolerance of a wide variety of functional groups.
Simple synthesis of 5-amino-8-nitro-7-aryl-3,7-dihydro-2H-thiazolo[3,2-a]pyridine-6-carboxamide derivatives
Hosseini, Fahimeh Sadat,Nasri, Shima,Bayat, Mohammad
, p. 622 - 632 (2018)
An easy, efficient, and environmentally benign synthesis of new class of thiazolopyridine carboxamide derivatives is reported via one-pot, multi-component reaction of 2-(nitromethylene)thiazolidine derived from the addition of cysteamine hydrochloride to nitro ketene dithioacetal with aromatic aldehydes and cyanoacetamide using catalytic amount of triethylamine (Et3N) in ethanol/water at reflux in good to excellent yields.
Synthesis of highly functionalized hydropyridones: thiazolo[3,2-a]pyridin-5-one-6-carbohydrazones and tetrahydroimidazo[1,2-a]pyridin-5-one-2-carbohydrazones
Vala, Masoud Mohamadi,Bayat, Mohammad,Bayat, Yadollah
, p. 542 - 560 (2020)
Synthesis of functionalized 2-pyridone derivatives from thiazolo[3,2-a]pyridine-6-carbohydrazides or tetrahydroimidazo[1,2-a]pyridine-6-carbohydrazides was developed using acetic acid as solvent at 70°C. Various carbohydrazides could be applied to this protocol, and the desired 2-pyridone products were isolated in excellent yields by simple filtration. This method has several additional advantages, such as simple operation, mild reaction conditions, simple work up, easy product isolation, and preparation of potentially bioactive compounds.
Rapid synthesis of (E)-5-amino-N′-benzylidene-8-nitro-7-aryl-3,7-dihydro-2H-thiazolo[3,2-a]pyridine-6-carbohydrazide derivatives
Bayat, Mohammad,Hosseini, Fahimeh Sadat
, p. 279 - 293 (2018)
A variety of novel thiazolo/oxazolo pyridine derivatives were synthesized via an efficient, one-pot, multi-component reaction of enamines derived from the addition of cysteamine hydrochloride/ethanolamine to 1,1-bis(methylthio)-2-nitroethene with aromatic aldehydes and cyanoacetohydrazide in the presence of catalytic amount of Et3N. This reaction includes some important aspects like simple operation under mild conditions, high atom economy, easy accessibility of reactants, simple workup procedure, and the use of EtOH/H2O as a green reaction medium.
An efficient one-pot synthesis of tetrahydrothiazolo[3,2-a]quinolin-6-one derivatives
Bayat, Mohammad,Hosseini, Fahimeh Sadat,Nasri, Shima
, p. 99 - 111 (2018)
The cysteamine hydrochloride as a practical precursor of 2-(nitromethylene)thiazolidine in the one-pot synthesis of thiazoloquinoline derivatives from aromatic aldehydes and dimedone is described. This protocol involved Michael reaction, imine–enamine tautomerization, and cyclization sequence. Simple operation under mild conditions, easy accessibility of reactants, short reaction times, simple workup procedure, high atom economy, and the use of ethanol/water as a green medium make this approach attractive for the synthesis of variety of such derivatives.
The structure modification of seven-membered aza-brigded neonicotinoids in order to investigate their impact on honey bees
Cao, Xiaofeng,Chen, Xi,Chen, Yuce,Li, Zhong,Xu, Xiaoyong
, p. 835 - 844 (2021/05/29)
In order to explore the relationship between the structure and the toxicity to honey bees of seven-membered aza-bridged neonicotinoids, 16 novel seven-membered aza-bridged neonicotinoid analogues are synthesized by replacing the pyridine ring, and changing the substituents on the pyridine ring, the electron-withdrawing group NO2 and the imidazole ring of our previously developed aza-bridged neonicotinoid 1-[(6-chloropyridin-3-yl)methyl)]-10-(2,5-dimethylphenyl)-9-nitro-2,3,5,6,7,8-hexahydro-1H-5,8-epiminoimidazo azepine (C-29). The insecticidal bioactivities against cowpea aphid (Aphis craccivora) and the bee toxicities of these compounds are tested. Some of the title compounds present good insecticidal activities against cowpea aphid. The results also show that some of the title compounds exhibit lower bee toxicity than that of C-29 and imidacloprid. This suggests that changing the substituents on the neonicotinoids can influence the toxicity toward honey bees of these analogues.
Simple synthesis of new imidazopyridinone, pyridopyrimidinone, and thiazolopyridinone derivatives and optimization of reaction parameters using response surface methodology
Hosseini, Fahimeh Sadat,Bayat, Mohammad
, p. 30479 - 30488 (2019/10/04)
The reaction between ketene animal/ketene N,S-acetals (derived from diamines/cysteamine hydrochloride and 1,1-bis(methylthio)-2-nitroethene) with aromatic aldehydes, and Meldrum's acid led to the title compounds. The reaction conditions were optimized using response surface methodology (RSM). The two independent variables (temperature and water content of aqueous ethanol), and the responses (yield of product and reaction time) were studied. The range of each parameter selected was: T = 25-100 °C and water = 0-100%. The optimal values were: T = 72 °C and water = 33%. This work offers significant advantages including use of a green solvent, experimental simplicity, absence of catalyst, a simple work-up and purification process, moderate to good yields, and preparation of potentially bioactive compounds.
Method for synthesizing ranitidine
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Paragraph 0038; 0039; 0049; 0050; 0060; 0061; 0071; 0072, (2017/10/09)
A method for synthesizing ranitidine includes following steps: 1), dropwise adding sodium hydroxide water solution into 1, 1, 2-trichloroethane at 30-35 DEG C for reaction to obtain vinylidene chloride, wherein a mass ratio of 1, 1, 2-trichloroethan to sodium hydroxide is 1:0.3-0.33; 2), dropwise adding vinylidene chloride into mixed acid of concentrated hydrochloric acid and concentrated nitric acid at 20-25 DEG C for reaction for 2-4h, wherein a consumption ratio of vinylidene chloride to the mixed acid is 1:2-3; 3), adding cysteamine hydrochloride into sodium hydroxide and potassium hydroxide solution, and dropwise adding a product of the step 2) at 50-55 DEG C to obtain a closed-loop product; 4), enabling the closed-loop product to react with alcohol or methanol solution at room temperature for 14-18h to obtain an open-loop product; 5), adding the open-loop product and 2-[(dimethylamino)methyl]-5 chloromethyl-furan into potassium hydroxide or sodium hydroxide water solution for reaction at 40-50 DEG C for 2-4h to obtain ranitidine. The method lowers potential safety hazards and is simple and easy for industrial production.
Oxidation strategy for the synthesis of regioisomeric spiroisobenzofuranopyrroles: Facile entries to spiro[isobenzofuran-1,2′-pyrrole] and Spiro[isobenzofuran-1,3′-pyrrole] derivatives
Fan, Yefeng,Liu, Song,Chen, Nanyang,Shao, Xusheng,Xu, Xiaoyong,Li, Zhong
supporting information, p. 393 - 403 (2015/02/19)
Two practical and efficient approaches have been developed to synthesize two kinds of racemic spiroisobenzofuranopyrrole analogues as regioisomers. In the presence of sodium periodate, cis-indeno[1,2-b]pyrrol-4(1H)-ones were converted into spiro[isobenzofuran-1,2′-pyrrole] derivatives by a two-step process. In addition, oxidative reactions promoted by lead tetraacetate were demonstrated using cis-indeno[2,1-b]pyrrol-8(1H)-ones as substrates, affording spiro[isobenzofuran-1,3′-pyrrole] derivatives. The remarkable features of two approaches included mild and convenient reaction conditions, a broad substrate scope, and moderate to excellent yields. Possible mechanisms were proposed based on the comparison of the intermediates and products.
A rapid and efficient protocol for the synthesis of novel nitrothiazolo[3,2-c]pyrimidines via microwave-mediated Mannich cyclisation
Yildirim, Muhammet,?elikel, Derya,Dürüst, Ya?ar,Knight, David W.,Kariuki, Benson M.
, p. 2122 - 2128 (2014/03/21)
Several 6-substituted-8-nitrothiazolo[3,2-c]pyrimidine derivatives have been obtained very efficiently by a multicomponent cyclisation of 2-(nitromethylene)thiazolidine, formaldehyde and various aliphatic or aromatic amines in water, using both microwave
