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1.
《Journal of heterocyclic chemistry》2017,54(1):551-560
Pyridin‐2‐yl‐ and 4,6‐dimethylpyrimidin‐2‐yl‐cyanamides entered into an alkylation reaction in the form of sodium salts. Pyridin‐2‐yl cyanamide 2 was alkylated at endo‐nitrogen atom of pyridine ring, while 4,6‐dimethylpyrimidin‐2‐yl cyanamide 1 was effectively alkylated at exo‐nitrogen atom of amino cyanamide group. The alkylation of cyanamides 1 and 2 with phenacylbromide gave the corresponding acetophenone derivatives. As a result of their intramolecular cyclization reactions 3‐(4,6‐dimethylpyrimidin‐2‐yl)‐5‐phenyloxazol‐2(3H )‐imine in the case of cyanamide 1 and 2‐amino‐3‐benzoylimidazo[1,2‐a ]pyridine in the case of cyanamide 2 were formed. The alkylated derivatives of pyridin‐2‐ylcyanamide 2 possess visible blue fluorescence with the main peak at 421 – 427 nm. 相似文献
2.
《Journal of heterocyclic chemistry》2017,54(4):2258-2265
The present study emphasizes on the dealklylation of 3‐aryl‐5‐alkyl‐2‐oxo‐Δ4‐1,3,4‐oxadiazoles when reacted with formamide resulting in the formation of 2‐aryl‐2H‐1,2,4‐triazol‐3(4H )‐ones as major product. Subsequent reactions of 2‐aryl‐2H‐1,2,4‐triazol‐3(4H )‐one gave triazolo[3,4‐b ][1,3,4]thiadiazoles and triazolo[3,4‐b ][1,3,4]thiadiazines derivatives incorporated with 1,2,4‐triazol‐3‐one. 相似文献
3.
2‐Alkyl‐, 2‐aryl‐, and 2‐halo‐substituted derivatives of 7‐methyl‐6‐fluoro‐1,3,4‐thiadiazolo[3,2‐a]pyrimidin‐6‐one ( 3 ) were prepared by reaction of 2‐substituted 5‐amino‐1,3,4‐thiadiazoles ( 1 ) and ethyl 2‐fluoroacetoacetate ( 2 ) in polyphosphoric acid. A convenient procedure was developed for the synthesis of new 2‐amino derivatives of 2‐R‐7‐methyl‐6‐fluoro‐1,3,4‐thiadiazolo[3,2‐a]pyrimidin‐6‐one ( 5 ). J. Heterocyclic Chem., (2011). 相似文献
4.
Synthesis of 6‐(5‐Methylisoxazol‐3yl)‐3‐alkyl Sulfanyl‐[1,2,4]triazolo‐[3,4‐b][1,3,4]thiadiazoles 下载免费PDF全文
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
5.
Abdou O. Abdelhamid Abdelgawad A. Fahmi Basma S. Baaui 《Journal of heterocyclic chemistry》2012,49(5):1098-1107
2,3‐Dihydro‐1,3,4‐thiadiazoles, 2,3‐dihydro‐1,3,4‐selenadiazoles, and triazolino[4,3‐a]pyrimidines containing benzofuran moiety were prepared from the reaction of 2‐(2‐phenylhydrazono)‐1‐(5‐bromobenzofuran‐2‐yl)‐2‐chloroethanone with each of potassium thiocyanate, potassium selenocyanate, alkyl carbodithioate, and pyrmidine‐2‐thione derivatives. All the newly synthesized compounds were confirmed by elemental analysis, spectral data, and alternative route synthesis whenever possible. 相似文献
6.
《Journal of heterocyclic chemistry》2017,54(3):1872-1879
We report new method for preparation of 2‐amino‐5‐aryl‐1,3,4‐thiadiazoles by reaction of arylaldehyde with thiosemicarbazide and in the next step via cyclization of 2‐aryl hydrazinecarbothioamide in the presence of ZnCl2.6H2O or FeCl3.6H2O. Also, in this research, new substituted 1,3,4‐thiadiazolo‐[3,2‐α]pyrimidines were synthesized by the reaction of 2‐amino‐5‐aryl‐1,3,4‐thiadiazoles derivatives with DMAD or DEAD in the presence of K2CO3 under reflux conditions. The FT‐IR, 1H‐NMR, 13C‐NMR, elemental analysis and single‐ crystal X‐ray analysis confirm the structures of the products. 相似文献
7.
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
8.
2,3‐Dihydro‐1,3,4‐thiadiazoles, pyrazoles, pyrazolo[3,4‐d]pyridazines, thieno[2,3‐b]pyridines, pyrim‐idino[4′,5′:4,5]thieno[2,3‐b]pyridines and pyrrolo[3,4‐d]pyrazoles were obtained in a good yields by treatment of hydrazonoyl halides with each of alkyl carbodithioates, 3‐(dimethylamino)‐1‐naphtho[1,2‐d]furan‐2‐ylprop‐2‐en‐1‐one and N‐arylmalemides. 相似文献
9.
Lilija I. Kasyan Igor N. Tarabara Oxana A. Savel'yeva Andrey O. Kasyan 《Heteroatom Chemistry》2001,12(3):119-130
A number of stereoisomeric N‐[aryl(alkyl, cycloalkyl)carbonyl]‐exo(endo)‐5‐aminomethylbicyclo[2.2.1]hept‐2‐enes have been synthesized from bicyclo[2.2.1]hept‐2‐en‐exo(endo)‐5‐carbonitrile via reduction of the latter by lithium aluminum hydride and subsequent reactions of the resulting amines with aryl(alkyl, cycloalkyl)carbonyl chlorides and anhydrides. The direction of reaction of amides with peroxy acids does not depend on orientation of substituents in the bicyclic fragment: that is, for both exo‐ and endo‐isomers the epoxidations are completed by the formation of N‐[aryl(alkyl, cycloalkyl)carbonyl]‐exo(endo)‐5‐aminomethyl‐exo‐2,3‐epoxybicyclo[2.2.1] heptanes. The reduction of stereoisomeric epoxides by lithium aluminium hydride proceeds in different directions; that is, isomers with an exo‐oriented amido group form the substituted exo‐5‐alkylaminomethyl‐exo‐2,3‐epoxybicyclo[2.2.1]heptanes and the reactions of epoxides of endo‐amides are accompanied by intramolecular cyclization and completed by the formation of N‐[aryl(alkyl, cycloalkyl)]‐exo‐2‐hydroxy‐4‐azatricyclo[4.2.1.03,7]nonanes. The structures and stereochemical homogenity of the products have been confirmed by the analysis of 1H and 13C NMR spectra, correlation spectroscopy, and nuclear Overhauser enhancement spectroscopy experiments. We discuss the behavior of epoxides and provide an analysis of the coefficients of the atomic orbitals in the molecular orbital–linear combination of atomic orbitals equation (AM1 method). © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:119–130, 2001 相似文献
10.
C‐Selective and Diastereoselective Alkyl Addition to β,γ‐Alkynyl‐α‐imino Esters with Zinc(II)ate Complexes 下载免费PDF全文
Dr. Manabu Hatano Kenji Yamashita Mai Mizuno Orie Ito Prof. Dr. Kazuaki Ishihara 《Angewandte Chemie (International ed. in English)》2015,54(9):2707-2711
Since umpolung α‐imino esters contain three electrophilic centers, regioselective alkyl addition with traditional organometallic reagents has been a serious problem in the practical synthesis of versatile chiral α‐amino acid derivatives. An unusual C‐alkyl addition to α‐imino esters using a Grignard reagent (RMgX)‐derived zinc(II)ate was developed. Zinc(II)ate complexes consist of a Lewis acidic [MgX]+ moiety, a nucleophilic [R3Zn]? moiety, and 2 [MgX2]. Therefore, the ionically separated [R3Zn]? selectively attacks the imino carbon atom ,which is most strongly activated by chelation of [MgX]+. In particular, chiral β,γ‐alkynyl‐α‐imino esters can strongly promote highly regio‐ and diastereoselective C‐alkylation because of structural considerations, and the corresponding optically active α‐quaternary amino acid derivatives are obtained within 5 minutes in high to excellent yields. 相似文献
11.
Barbara Milczarska Katarzyna Gobis Henryk Foks Lukasz Golunski Pawel Sowinski 《Journal of heterocyclic chemistry》2012,49(4):845-850
In research of new biologically active compounds, the reactions of amino‐pyrazin‐2‐hydrazide and methylhydrazide with isothiocyanates, aromatic aldehydes, ketones, CS2, and formic acid were made. New thiosemicarbazides, 1,3,4‐thiadiazoles, 1,3,4‐oxadiazoles, and 1,2,4‐triazoles were obtained. New 4‐oxopteridine derivative 26 was also synthesized. 相似文献
12.
Syntheses of New Unsymmetrical 2,5‐Disubstituted‐1,3,4‐oxadiazoles and 1,2,4‐Triazolo[3,4‐b]‐1,3,4‐thiadiazoles Bearing Thieno[2,3‐c]pyrazolo Moiety 下载免费PDF全文
Shivaraj P. Patil Shrikant B. Kanawade Dinesh C. Bhavsar Prashant S. Nikam Sachin A. Gangurde Raghunath B. Toche 《Journal of heterocyclic chemistry》2014,51(2):368-373
New series of (thieno[2,3‐c]pyrazolo‐5‐yl)‐[1,2,4]triazolo[3,4‐b][1,3,4]thiadiazoles 10a , 10b , 10c and (thieno[2,3‐c]pyrazol‐5‐yl)‐1,3,4‐oxadiazol‐3(2H)‐yl)ethanones 6a , 6b , 6c has been synthesized from thieno[2,3‐c]pyrazole‐5‐carbohydrazide 3 by multistep reaction sequence. (5‐Aryl‐1,3,4‐oxadiazol‐2‐yl)‐1H‐thieno[2,3‐c]pyrazoles 4a , 4b , 4c were also synthesized from thieno[2,3‐c]pyrazole‐5‐carbohydrazide 3 by cyclization with various aromatic carboxylic acids. The hydrazide 3 was obtained by reaction of thieno[2,3‐c]pyrazole‐5‐carboxylate 2 with hydrazine hydrate in good yield, and compound 2 was obtained by the reaction of 5‐chloro‐3‐methyl‐1‐phenyl‐1H‐pyrazole‐4‐carbaldehyde 1 and 2‐ethyl thioglycolate in presence of sodium alcoholate in good yield. 相似文献
13.
The bifunctional 3/4‐[acetyl]phenylsydnones 1a, 1b were subjected to a one‐pot ring conversion to 3‐[3/4‐acetyl]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 2a, 2b , which on further bromination yielded the 3‐[3/4‐bromoacyl]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 3a, 3b . Reaction of these compounds with thiourea yielded the 3‐[3/4‐(2‐aminothiazol‐4‐yl)]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 4a, 4b . The other thiazole derivatives 5a, 5b–7a, 7b were prepared by using thiosemicarbazide, thioacetamide, and thiobenzamide, respectively. In another reaction of the bromoacetyl compounds ( 3a, 3b ) with 2‐aminopyridine and 2‐aminothiazole, the fused biheterocyclic compounds 3‐[3/4‐imidazo‐[1,2‐a]pyridine‐2‐yl]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 8a, 8b and 3‐[3/4‐imidazo‐[2,1‐b]‐thiazol‐6‐yl]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 9a, 9b were obtained. The 3‐[3/4‐(benzofuran‐2‐carbonyl)]phenyl‐5‐methyl‐3H‐[1,3,4]‐oxadiazol‐2‐ones 10a, 10b were obtained by treatment of compounds 3a, 3b with o‐hydroxy benzaldehyde. Most of these compounds exhibited antifungal activity greater than the reference drugs used. © 2007 Wiley Periodicals, Inc. Heteroatom Chem 18:50–54, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20255 相似文献
14.
Valery S. Tolkunov Igor F. Perepichka Vladimir I. Dulenko 《Journal of heterocyclic chemistry》2005,42(5):811-817
Reaction of 2‐acyl‐6‐methylbenzo[b]furan‐3‐acetic acids and their derivatives such as amides and esters with hydrazine does not give expected 1‐alkyl‐5H‐benzofuro[2,3‐e]diazepin‐4‐ones ones but results in 2‐amino‐7‐methyl‐2H‐benzo[4,5]furo[2,3‐c]pyridin‐3‐ones or (3‐R‐6‐methylbenzo[b]furan‐2‐yl)alkyl ketone azines. 相似文献
15.
3‐Methyl‐2‐benzofurancarboxylic acid hydrazide ( 2 ) reacts with carbon disulfide and pota‐ ssium hydroxide to give the corresponding potassium carbodithioate salt 3 . Treatment of the latter salt with hydrochloric acid, hydrazine hydrate, and with phen‐ acyl bromide afforded the corresponding 1,3,4‐oxadia‐ zole‐5‐thione 4 , 4‐amino‐1,2,4‐triazole‐5‐thione 5 , and thiazolidine‐2‐thione 9 derivatives, respectively. The reaction of either 1,3,4‐oxadiazole‐5‐thione 4 or 4‐amino‐1,2,4‐triazole‐5‐thione 5 with phenacyl bromide resulted in the formation of 1,2,4‐triazolo[3, 4‐b]‐1,3,4‐thiadiazine derivative 8 . Treatment of compounds 3 or 4 with hydrazonoyl halides 10a–d furn‐ ished the same 1,3,4‐thiadiazol‐2‐ylidene derivatives 11a–d . The 7‐arylhydrazono‐1,2,4‐triazolo[3,4‐ b ]‐1, 3,4‐thiadiazine derivatives 12a–d were obtained either by treatment of 4‐amino‐1,2,4‐triazole‐5‐thione 5 with hydrazonoyl halides 10a–d or by coupling of the 1,2,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazine derivative 8 with diazonium salts. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:621–627, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20162 相似文献
16.
Yu‐Xia Da Ji‐Hua Zhu Zhang Zhang Xiao‐Dong Jia Cai‐Xia Yang Zheng‐Jun Quan 《Journal of heterocyclic chemistry》2012,49(1):102-105
A series of 2,5,6‐trisubstituted imidazo[2,1‐b][1,3,4]thiadiazoles via Mannich reaction of imidazo[2,1‐b][1,3,4]thiadiazoles with morpholine and formaldehyde were synthesized. Structures of all the newly synthesized compounds are well supported by spectral data such as IR, NMR, Mass, and Elemental analysis. Compound 3a has been confirmed by X‐ray diffraction studies. J. Heterocyclic Chem., (2012). 相似文献
17.
Several 3‐[5‐methyl‐1‐(4‐methylphenyl)‐1,2,3‐triazol‐4‐yl]‐6‐substituted‐1,3,4‐triazolo[3,4‐b]‐1,3,4‐thiadiazoles have been synthesized and the structures of these compounds were established by elemental analysis, MS, IR and 1H NMR spectral data. 相似文献
18.
《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
19.
Synthesis and Pharmacological Evaluation of a Novel Series of 2‐((2‐Aryl thiazol‐4‐yl)methyl)‐5‐(alkyl/alkylnitrile thio)‐1,3,4‐oxadiazole Derivatives as Possible Antifungal Agents 下载免费PDF全文
Shivaji H. Shelke Pravin C. Mhaske Sridhar Kumar Kasam Vivek D. Bobade 《Journal of heterocyclic chemistry》2014,51(6):1893-1897
In the present investigation, a novel series of 2‐[(2‐arylthiazol‐4‐yl)methyl]‐5‐(alkyl/alkylnitrile thio)‐1,3,4‐oxadiazole derivatives were synthesized by cyclo‐condensation of 2‐(2‐substituted thiazol‐4‐yl)aceto hydrazide with carbon disulfide followed by S‐alkylation with alkyl halide in dry acetone. All the newly synthesized compounds were characterized by spectral (IR, 1H NMR, 13C NMR, mass, and elemental analysis) methods. The title compounds were screened for in vitro antifungal activity and most of the synthesized compounds show moderate to good antifungal activity. 相似文献
20.
Synthesis of 2‐Substituted 3‐Alkylidene‐2,3‐dihydro‐1H‐isoindol‐1‐imines through Cyclization of [1‐(2‐Cyanophenyl)alkylidene]aminide Intermediates Generated from the Reaction of 2‐(1‐Azidoalkyl)benzonitriles with NaH 下载免费PDF全文
A convenient sequence for the preparation of 3‐alkylidene‐2,3‐dihydro‐1H‐isoindol‐1‐imine derivatives 6 has been developed. Thus, 2‐(1‐azidoalkyl)benzonitriles 2 , readily accessible from 2‐alkylbenzonitriles, are allowed to react with NaH in DMF at 0° to room temperature to generate [1‐(2‐cyanophenyl)alkylidene]aminide intermediates 3 , of which cyclization and the subsequent rearrangement, followed by alkylation with alkyl halides, affords 2‐substituted 1‐alkylidene‐2,3‐dihydro‐1H‐isoindol‐2‐imines 6 in generally moderate yields. 相似文献