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1.
The reaction of 1,3‐diphenyl‐2‐(phenylimino)‐3‐(ylidenemethyl‐acetate)‐1‐propanone (5) with trisdialkylaminophosphines (6a,b) in refluxing toluene afforded the new oxazaphospholene products (7a–b) . On the other hand, the cyclic azaphospholene adducts 8a–b were isolated from the reaction of 5 with 6a,b without solvent. Trialkyl phosphites 1b–c react with compound 5 to give the respective dialkyl phosphate products (9a,b) . Moreover, trisdialkylaminophosphines (6a,b) react with 2a and 2b to give the dipolar adducts 10a,b and the phosphonate products 11a,b, respectively. Possible reaction mechanisms are considered, and the structural assignments are based on compatible analytical and spectroscopic results. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:511–517, 2001 相似文献
2.
Oleksandr V. Golovchenko Stepan G. Pilyo Vladimir S. Brovarets Alexander N. Chernega Boris S. Drach 《Heteroatom Chemistry》2004,15(6):454-458
Available 2‐acylamino‐3,3‐dichloroacrylonitriles, when treated with hydrazine hydrate, provide 2‐alkyl‐ or 2‐aryl‐5‐hydrazino‐1,3‐oxazole‐4‐carbonitriles that readily add alkyl or aryl isothiocyanates and the adducts formed recyclize on heating. Finally, the synthesis results in 5‐alkyl(aryl)amino‐1,3,4‐thiadiazol‐2‐yl(acylamino)acetonitriles or the products of their further cyclization, 2‐(5‐amino‐1,3‐ oxazol‐2‐yl)‐1,3,4‐thiadiazole derivatives. The structures of the novel substituted 1,3,4‐thiadiazoles are corroborated spectroscopically as well as by X‐ray diffraction method. © 2004 Wiley Periodicals, Inc. Heteroatom Chem 15:454–458, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20041 相似文献
3.
Saifidin Safarov Muhamacho Ahmadovich Kukaniev Heinz Kolshorn Herbert Meier 《Journal of heterocyclic chemistry》2005,42(6):1105-1109
2‐Amino substituted 7H‐1,3,4‐thiadiazolo[3,2‐α]pyrimidin‐7‐ones 11a‐e were prepared by the reaction of 2‐bromo‐5‐amino‐1,3,4‐thiadiazole ( 1b ) and diketene ( 8 ), subsequent cyclocondensation ( 9b → 3b ) and displacement of the bromo substituents by the reaction with primary or secondary amines ( 3b → 11a‐e ). The hydrogen atom 6‐H in the heterobicycle 3b is replaced by a Cl or Br atom in the transformation of 3b → 14a,b. The 2‐bromo‐6‐chloro compound 14a reacts chemoselectively in the 2‐position with dimethylamine ( 14a → 15 ). The structure elucidations are based on one‐ and two‐dimensional NMR techniques including a heteronuclear NOE measurement. 相似文献
4.
Bassam A. Abu Thaher Jalal A. Zahra Mustafa M. El‐Abadelah 《Journal of heterocyclic chemistry》2002,39(5):901-904
2‐Aminobenzoic acid reacts readily, in the presence of triethylamine, with hydrazonoyl chlorides ( 5a‐c ) (precursors of the reactive nitrile imine 1,3‐dipolar species) to afford high yields of the corresponding acyclic amidrazone adducts ( 6a‐c ). The latter adducts undergo, in THF in presence of 1,1‐carbonyldiimida‐zole, smooth intramolecular cyclization involving the activated carboxyl and the NH‐ termini to deliver unequivocally the respective dihydro‐1,3,4‐benzotriazepin‐5‐ones ( 7a‐c ). 相似文献
5.
Alajos Grün Istvn Gbor Molnr Bla Bertk Istvn Greiner Gyrgy Keglevich 《Heteroatom Chemistry》2009,20(6):350-354
The synthesis of hydroxy‐methylenebisphosphonates ( 2a–c ) by the addition of dialkyl phosphite to the carbonyl group of the corresponding α‐oxophosphonate ( 1a–c ) was studied under microwave irradiation (MW) and solventless conditions in the presence of dialkylamine as the catalyst. After optimization, products 2a and 2b were obtained selectively and in good yields avoiding the formation of the phosphonate‐phosphate by‐product ( 3a and 3b ) that is the result of a rearrangement. The MW‐assisted synthesis of hydroxybisphosphonates ( 2a and 2b ) offers complete conversions and a chemoselectivity of 100% as compared to the not so efficient thermal reaction. At the same time, the phenyl‐substituted methylenebisphosphonate 2c could be obtained in only 75% selectivity. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:350–354, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20558 相似文献
6.
Azita Javidnia Tahmineh Akbarzadeh Loghman Firoozpour Mehdi Khoobi Abbas Shafiee Alireza Foroumadi 《Journal of heterocyclic chemistry》2011,48(2):454-457
Starting from 5‐hydroxymethyl‐2‐mercapto‐1‐methyl‐1H‐imidazole (1), a series of 2‐(1‐methyl‐2‐methylsulfonyl‐1H‐imidazol‐5‐yl)‐5‐alkylthio and 5‐alkylsulfonyl‐1,3,4‐thiadiazole derivatives ( 9a , 9b , 9c , 9d and 10a , 10b , 10c , 10d ) were prepared as potential antimicrobial agents. The structure of the obtained compounds was confirmed by NMR, IR, Mass spectroscopy, and elemental analysis. J. Heterocyclic Chem., (2010) 相似文献
7.
Synthesis of 6‐(5‐Methylisoxazol‐3yl)‐3‐alkyl Sulfanyl‐[1,2,4]triazolo‐[3,4‐b][1,3,4]thiadiazoles
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A new series of isoxazole substituted fused triazolo‐thiadiazoles have been synthesized by the cyclocondensation of 5‐methylisoxazole‐3‐craboxylic acid and 4‐amino 1,2‐4‐triazole‐ 3,5‐dithiol using phosphorous oxychloride. The cyclised intermediate 6‐(5‐methylisoxazol‐3‐yl)‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazole‐3‐thiol later on S‐alkylated with different alkyl halides in ethanol to give the title products in good to excellent yields. 相似文献
8.
Zheng‐Jun Quan Rong‐Guo Ren Yu‐Xia Da Zhang Zhang Xi‐Cun Wang 《Heteroatom Chemistry》2011,22(5):653-658
Treatment of mercapto‐heterocyclic compounds with diethyl phosphite in the presence of 4‐dimethylaminopyridine (DMAP) in tetrachloroethylene has given the S‐ethylated product in good yields and high chemoselectivity. This procedure is compatible with a wide range of SH‐compounds such as 1,3,4‐oxadiazole‐2‐thiol, 1,3,4‐thiadiazole‐2‐thiol, benzo[d]thiazole‐2‐thiol, and substituted benzenethiol. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:653–658, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20729 相似文献
9.
Amal Feddouli Moulay Youssef Ait Itto Aïssa Hasnaoui Didier Villemin Paul‐Alain Jaffrs Jana Sopkova‐De Oliveira Santos Abdelkhalek Riahi FranOis Huet Jean‐Claude Daran 《Journal of heterocyclic chemistry》2004,41(5):731-735
Herein we report an efficient one pot synthesis of new chiral 4,5‐dihydro‐4‐arylspiro[1,3,4‐thiadiazole]‐5,2′‐camphane‐2‐carboxylic acid ethyl esters 5–7 and 4,5‐dihydro‐3‐arylspiro[1,4,2‐oxathiazole]‐5,2′‐camphane 11–13 , using 1,3‐dipolar cycloaddition of nitrilimines 2–4 and nitrile oxides 8–10 to (1R)‐thiocamphor 1 respectively. The structure of the newly prepared 1,3,4‐thiadiazoles 5–7 (obtained as pure diastereoisomers) were fully established via spectroscopic analysis and X‐ray structural analysis which proved the absolute configuration of the C5 spiranic carbon to be (R). NMR spectral analysis were also very useful to show the new 1,4,2‐oxathiazoles 11–13 are mixtures of two (5R)/(5S) diastereoisomers with the ratio 6:4,7:3 and 6:4 respectively. 相似文献
10.
The reaction of 2‐benzylidene‐1,3‐diphenylpropanetrione ( 1a ) with phosphorus ylides 2a–c afforded the new phosphonium ylides 4a–c . Trialkyl phosphites 3a–c react with 1a to give the respective dialkyl phosphonate products 5a–c . On the other hand, the olefinic compounds 6 and 7 were isolated from the reaction of 1b with Wittig reagents 2 . Moreover, trialkyl phosphites reacted with 1b to give products 8a–c . Possible reaction mechanisms are considered, and the structural assignments are based on analytical and spectroscopic evidence. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:57–64, 2000 相似文献
11.
Saifidin Safarov Muhamacho A. Kukaniev Elena Karpuk Herbert Meier 《Journal of heterocyclic chemistry》2007,44(1):269-271
12.
C‐acyl‐N‐(3‐phenyl‐5‐pyrazolyl)hydrazonoyl chlorides 1a,b react with potassium thiocyanate and potassium selenocyanate to give 5‐acyl‐2,3‐dihydro‐2‐imino‐3‐(3′‐phenyl)pyrazol‐5′‐yl)‐1,3,4‐thiadiazoles 2a,b and 5‐acetyl‐2,3‐dihydro;‐2‐imino‐3‐(3′‐phenyl)pyrazol‐5′‐yl)‐1,3,4‐selenadiazole 10a,b . Also, 2‐[mercapto‐(methylthio)methylene]indan‐1,3‐dione 16 reacts with hydrazonoyl halides 15 and 22–25 to afford 2,3‐dihydro‐1,3,4‐thiadiazoles 19 and 26–29 , respectively. Structures of the newly synthesized compounds are elucidated on the basis of spectral data, chemical transformations, and alternative synthesis methods. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:468–474, 2001 相似文献
13.
《Journal of heterocyclic chemistry》2017,54(4):2360-2366
Condensation of 2‐amino‐5‐phenyl‐5H‐thiazolo[4,3‐b] [1,3,4] thiadiazoles ( 1 ) with some carboxylic acid derivatives furnished corresponding compounds 2–4 , respectively. Alkylation of 1 with benzoylchloride and 4‐chlorobenzyl chloride afforded thiazolo[4,3‐b][1,3,4]thiadiazole derivatives 5 and 6 , respectively. Similarly, transformation of 1 with chloroacetyl chloride yielded chloroacetamide derivative 7 . The later compound was subjected to react with potassium thiocyanate or piperazine whereby, the binary thiazolidinone derivative 8 and N 1 ,N4‐disubstituted piperazine 9 were produced, respectively. Also, the reactivity of 1 toward various active methylene reagents was investigated. Accordingly, our attempts to synthesize the tricyclic heterocyclic system 10 , 11′ , 12 ′ by reaction of 1 with chloroacetonitrile, 4‐oxo‐4‐phenylbutanoic acid and/or diethylmalonate in presence of acetyl chloride was furnished 10 , 11 , and 12 . The newly synthesized compounds were screened as antimicrobial agent. 相似文献
14.
The cyclization of 1‐amino‐2‐mercapto‐5‐[1‐(4‐ethoxyphenyl)‐5‐methyl‐1,2,3‐triazol‐4‐yl]‐1,3,4‐triazole which was synthesized from p‐ethoxyaniline with various triazole acid in absolute phosphorus oxychloride yields 3,6‐bis(1,2,3‐triazolyl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazole derivatives 9a?j , and their structures are established by MS, IR, CHN and 1H NMR spectral data. 相似文献
15.
Nuran Kahriman Nagihan Yilmaz Iskender Murat Yücel Nurettin Yayli Emine Demir Zihni Demirbağ 《Journal of heterocyclic chemistry》2012,49(1):71-79
A simple environmentally friendly solid‐phase microwave‐assisted method was used to synthesis of the 1,3′‐diazaflavanone ( 2 ) and 1,3′‐diazaflavone ( 3 ) from the cyclization of 2′‐amino (E)‐3″‐azachalcone ( 1 ). Ten new N‐alkyl (C5–12,14,15)‐substituted 1,3′‐diazaflavanonium bromides ( 2a–j ) were prepared from compound 2 with corresponding alkyl halides in acetonitrile under reflux. In addition, nine new N,N′‐dialkyl (C5–12,14)‐substituted 1,3′‐diazaflavonium bromides ( 3a–i ) were also synthesized from compound 3 with corresponding alkyl halides using basic silica in acetonitrile. The antimicrobial activities of compounds 1–3 , 2a–j , and 3a–i were tested against Gram‐positive (G+) (Bacillus subtilis, Staphylococcus epidermidis, Staphylococcus aureus, and Enterococcus faecalis) and Gram‐negative (G?) (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa, Proteus vulgaris, Salmonella typhimirium, Yersinia pseudotuberculosis, and Enterobacter cloaceae) microorganisms. They showed good antimicrobial activity against the Gram‐positive bacteria tested with the minimal inhibitory concentration values less than 7.8 μg/mL in most cases. The optimum length of the alkyl chain for better and broader activity is situated in the range of 9–12 carbon atoms in the series of compounds 2a–j and five to six carbon atoms in the series of compounds 3a–i . The nonalkylated compounds 1–3 were not effective, as were the ones alkylated with five or six C alkyl groups ( 2a and 2b ) and 8–13 C alkyl groups for N,N′‐dialkyl compounds ( 3c–3i ). The antimicrobial activity increased as the length of the alkyl substitution increased from 8 to 12 carbons in compounds 2a–j . However, antimicrobial activity decreased as the length of the alkyl substitution increased from 7 to 13 carbons in compounds 3c–i . J. Heterocyclic Chem., (2012) 相似文献
16.
Treatment of 3‐(3‐methylbenzofuran‐2‐yl)‐3‐oxopropanenitrile ( 1 ) with phenyl isothiocyanate afforded the thioacetanilide derivative 3 , which when reacted with α‐haloketones, α‐halodiketones, and hydrazonoyl chlorides gives thiophene, 1,3‐oxathiole, and 1,3,4‐thiadiazole derivatives 6a,b, 10a,b and 14a–g , respectively. Treatment of 3‐methyl‐2‐benzofurancarboxylic acid hydrazide ( 15 ) with benzaldehyde followed by bromine afforded the 1,3,4‐oxadiazole derivative 18 . Treatment of the acid hydrazide 15 with phenyl isothiocyanate gave the thiosemicarbazide 20 . Compound 20 could be converted into 1,3,4‐oxadiazole, 1,2,4‐triazole‐3‐thione, and 1,3,4‐thiadiazole derivatives 21, 22 , and 23 , respectively. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:294–300, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20298 相似文献
17.
The reaction of 2‐thioxo‐4‐thiazolidinone ( 1a ) with phosphorus ylides 2a and 2b afforded compounds 5 and 6. On the other hand, formylmethylenetriphenylphosphorane (2c) reacts with 1a and its N‐methyl derivative 1b to give the new complicated phosphonium ylides 7a,b, respectively. Reactions of 1b with ylides 2a and 2d gave rise to the olefinic compound 8 and the new phosphorane product 9. Moreover, dialkyl phosphites 3a,b and trialkyl phosphites 4a–c react with 1a to give both the alkylated products 10a–c and the dimeric compounds 11,12. A mechanism is proposed to explain the formation of the new products.© 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 337–341, 1999 相似文献
18.
Corrosion inhibition and performance evaluation on 2,5‐diaryl‐1,3,4‐thiadiazole and its derivatives
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Xiaona Pan Lin Liu Qiang Zhang Jianhua Qian 《Surface and interface analysis : SIA》2016,48(6):373-382
Using electrochemical impedance spectroscopy (EIS) and scanning electronic microscopy (SEM), this paper evaluated the inhibition effect of four 2,5‐diaryl‐1,3,4‐thiadiazole and its derivatives named 2,5‐diphenly‐1,3,4‐thiadiazole (DPTD), 2,5‐di(2‐hydroxyphenly)‐1,3,4‐thiadiazole (2‐DHPTD), 2,5‐di(3‐hydroxyphenly)‐1,3,4‐thiadiazole (3‐DHPTD), and 2,5‐di(4‐hydroxyphenly)‐1,3,4‐thiadiazole (4‐DHPTD) on silver strip corrosion in 50 mg/l sulfur–ethanol solution under room temperature. The experiments indicated that the inhibition efficiency increased with increasing inhibitor concentrations, and the increasing order was (4‐DHPDT) > (3‐DHPDT) > (2‐DHPDT) > (DPDT). Quantum chemical calculation was applied to correlate inhibition performances with their electronic structural parameters of thiadiazole derivatives. Molecular dynamics simulations (DFT) were used to optimize the equilibrium configurations of the inhibitor molecules on the silver surface and to investigate the molecular structure effect on the corrosion inhibition efficiency. The efficiency order of the investigated inhibitors, which was obtained by experimental results, was verified by theoretical calculations. Contact angle (CA) analysis was also carried out, and finally confirmed the existence of the adsorbed film which prevailed in addition of thiadiazole derivatives. CA analysis indicated that the film of n‐DHPTD (n = 2,3,4) was hydrophilic, owing to two hydroxyl groups in their molecular. The adsorption of these compounds onto silver strip from 50 mg/l S‐ethanol system obeys Langmuir adsorption isotherm, and it belongs to mixed‐type adsorption mainly dominated by chemisorption. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
19.
A series of O,O‐diphenyl 1‐(5‐alkyl‐1,3,4‐thiadiazol‐2‐yl)aminoarylmethylphosphonates was synthesized by the three‐component condensation reactions of 2‐amino‐5‐alkyl‐1,3,4‐thiadiazoles with triphenyl phosphite and aromatic aldehydes in acetic acid. The reaction conditions were discussed. The structures of products were confirmed by 1H‐NMR, IR, MS, and elemental analyses. The results of preliminary bioassay showed that the new compounds possess fungicidal activity. © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:317–322, 2000 相似文献
20.
Madhava Rao Mannam Srimurugan S. Pramod Kumar R. S. Prasad K 《Journal of heterocyclic chemistry》2019,56(8):2179-2191
A new series of 1‐(5‐(benzylsulfinyl)‐3‐methyl‐1,3,4‐thiadiazol‐2(3H)‐ylidene)‐thiourea/urea derivatives ( 1a – j ) were designed and synthesized. For the first time, (i) a new process was developed for N‐methylation of 1,3,4‐thiadiazole moiety using dimethyl carbonate an environmentally benign reagent in presence of N,N,N′,N′‐tetramethylethylenediamine and (ii) the sulfide was selectively oxidized to sulfoxide in higher yield by using chlorine (g) in aqueous acetic acid media under mild reaction condition. The synthesized compounds ( 1a – j ) were investigated for their antimicrobial activities. The tested compounds ( 1a – j ) were exhibited moderate to excellent antibacterial activities against both Gram‐positive and Gram‐negative bacterial strains. The same compounds exhibited good antifungal activities against selected fungal strains. Particularly, the compounds 1b , 1d , 1h , and 1i were proved to be promising leads exhibiting both antibacterial and antifungal activities compared with standard drugs, ciprofloxacin, and fluconazole. The presence of 1,3,4‐thiadiazole moiety has a significant role in the display of antimicrobial activity. In addition, the presence of both sulfinyl and thiourea or urea functionalities has enhanced the activity as per obtained antimicrobial activity data. 相似文献