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1.
《Journal of heterocyclic chemistry》2017,54(4):2405-2416
3(5)‐Aminopyrazole derivative ( 6 ) has been synthesized by the reactions of the versatile unreported 2‐cyano‐N ′‐(1‐(3‐methyl‐6‐phenylimidazo[2,1‐b ]thiazol‐2‐yl)ethylidene)acetohydrazide ( 3 ) with phenyl isothiocyanate in KOH/DMF solution followed by reaction with methyl iodide and hydrazine hydrate. Reaction of compound 6 with some 1,3‐dicarbonyl compounds yielded pyrazolo[1,5‐a ]pyrimidine derivatives ( 14 – 17 ). Alkylation of compound 6 with various halo reagents, followed by intramolecular cyclization, yielded the corresponding imidazo[1,2‐b ]pyrazole derivatives 27 , 29 , 31 , and 33 . All newly synthesized compounds were elucidated by considering the data of both elemental analysis and spectral data. 相似文献
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Treatment of methyl propiolate and 2‐(thiophen‐2‐yl)benzaldehyde, 2‐(thiophen‐3‐yl)benzaldehyde or 2‐(furan‐3‐yl)benzaldehyde with tetrabutylammonium iodide/zirconium (IV) chloride or treatment of methyl acrylate and the same aldehydes with 1,4‐diazabicyclo[2,2,2]octane and triethanolamine induce an aldol‐type reaction to furnish Baylis‐Hillman adducts β‐iodo‐α‐(hydroxymethyl)acrylates or α‐(hydroxy‐methyl)acrylates, respectively. These can be used for the preparation of indenothiophenes and indenofurans having acrylic acid unit by intramolecular Friedel‐Crafts reaction with sulfuric acid in tetrachloromethane. 相似文献
4.
Teresa M. V. D. Pinho e Melo Clara S. B. Gomes Maria I. L. Soares Antanio M. d'A Rocha Gonsalves Jos A. Paixo Ana M. Beja Manuela Ramos Silva 《Journal of heterocyclic chemistry》2004,41(4):493-497
3‐Carbethoxy‐5‐phenyl‐5H,7H‐thiazolo[3,4‐c]oxazol‐4‐ium‐1‐olate was generated from (2R,4R)‐N‐ethoxyoxalyl‐2‐phenylthiazolidine‐4‐carboxylic acid and its reactivity studied. This münchnone showed low reactivity as dipole although from the reaction with dimethyl acetylenedicarboxylate the corresponding (3R)‐3‐phenyl‐17H,3H‐pyrrolo[1,2‐c]thiazole‐5,6,7‐tricarboxylate could be isolated. The thermolysis of (2R,4R)‐N‐ethoxyoxalyl‐2‐phenylthiazolidine‐4‐carboxylic acid in refluxing acetic anhydride led to the synthesis of N‐(1‐ethoxycarbonyl‐2‐phenylvinyl)‐2‐phenyl‐4‐thioxo‐1,3‐thiazolidine. The structure of methyl (2R,4R)‐N‐ethoxyoxalyl‐2‐phenylthiazoliddine‐4‐carboxylate was determined by X‐ray crystallography. 相似文献
5.
The imidazo[1,2‐a]pyridines are an important target in organic synthetic chemistry and have attracted critical attention of chemists mainly due to the discovery of the interesting properties exhibited by a great number of imidazo[1,2‐a]pyridine derivatives. Although lots of synthetic methods of imidazo[1,2‐a]pyridines have been developed in the past years, the chemistry community faces continuing challenges to use green reagents, maximize atom economy and enrich the functional group diversity of product. Undoubtedly, with its low cost and lack of environmentally hazardous byproducts, cascade reactions and C?H functionalizations are ideal strategies for this field. In this record we highlight some of our progress toward the goal to synthesis of imidazo[1,2‐a]pyridine derivatives through carbene transformations or C?H functionalizations. 相似文献
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Nimesh M. Shah Manish P. Patel Ranjan G. Patel 《Journal of heterocyclic chemistry》2012,49(6):1310-1316
A simple and efficient method has been developed for the synthesis of 1H‐pyrazolo[1,2‐b]phthalazine‐5,10‐dione derivatives through a one‐pot three‐component condensation reaction of 2‐chloro‐3‐formyl quinolines, malononitrile/ethyl cyanoacetate and 2,3‐dihydro‐1,4‐phthalazinedione using a catalytic amount of piperidine in refluxing ethanol. All the synthesized compounds were screened for their antibacterial activity against a panel of pathogenic strains of bacteria and fungi. 相似文献
8.
M. L. Chenna Reddy Vineetkumar B. Patil Fazlur Rahman Nawaz Khan Vadivelu Saravanan 《Journal of heterocyclic chemistry》2019,56(5):1486-1497
A new method has been developed for the synthesis of imidazo[1,2‐a]pyridines, imidazo[2,1‐b]thiazoles, and benzo[d]imidazo[2,1‐b]thiazoles attached to a cycloalkyl or saturated heterocycle containing a tertiary hydroxy substitution. Readily available substituted 2‐aminopyridines, 2‐aminothiazoles, and 2‐aminobenzothiazoles were treated with bromohydroxycycloalkyl ethanones to afford the desired products in good yields. 相似文献
9.
《Journal of heterocyclic chemistry》2017,54(6):3440-3446
2‐(1H ‐benzo[d ]imidazol‐2‐yl)anilines reacted with haloketones including 5‐chloropentan‐2‐one and 6‐chlorohexan‐2‐one catalyzed by iodine, giving benzo[4,5]imidazo[1,2‐c ]pyrrolo[1,2‐a ]quinazoline and 6H ‐benzo[4,5]imidazo[1,2‐c ]pyrido[1,2‐a ]quinazoline derivatives, respectively. This domino‐type reaction formed two new heterocycles and three new covalent bonds in one‐pot procedure and provided a green method for the synthesis of fused pentacyclic heterocycles bearing both quinazoline and benzimidazole moieties in ionic liquids. 相似文献
10.
Magdolna Solymár Márta Palkó Tamás Martinek Ferenc Fülöp 《Monatshefte für Chemie / Chemical Monthly》2002,133(11):1423-1430
Summary. The reactions of 1,2,3,4-tetrahydro-β-carboline-1-carboxylic acid and its ethyl ester with alkyl and aryl isothiocyanates
under mild conditions resulted in the corresponding thiohydantoin-fused tetrahydro-β-carbolines. Treatment of the ethyl ester
with isocyanates furnished ethyl 2-alkyl- or arylcarbamoyl-1,2,3,4-tetrahydro-β-carboline-1-carboxylates which were transformed
to hydantoin-fused tetrahydro-β-carbolines. The structures of the thiohydantoin compounds, involving two conformers and the
presence of keto-enol tautomerism, were determined by NMR spectroscopy.
Corresponding author. E-mail: fulop@pharma.szote.u-szeged.hu
Received February 2, 2002. Accepted (revised) March 4, 2002 相似文献
11.
A series of novel 6‐[(1,3,4‐thiadiazol‐2‐yl)sulfanyl]‐7‐phenylpyrazolo[1,5‐a]pyrimidines, 5‐phenyl‐6‐[(1,3,4‐thiadiazol‐2‐yl)sulfanyl]imidazo[1,2‐a]pyrimidines, and 2‐phenyl‐3‐[(1,3,4‐thiadiazol‐2‐yl)sulfanyl]pyrimido[1,2‐a]benzimidazoles have been synthesized in four steps starting with 2‐hydroxyacetophenone. The intermediate 3‐[(1,3,4‐thiadiazol‐2‐yl)sulfanyl]‐4H‐1‐benzopyran‐4‐ones reacted with pyrazol‐3‐amines, 5‐methylpyrazol‐3‐amine, and 1H‐imidazol‐2‐amine, 1H‐benzimidazol‐2‐amine via a cyclocondensation to give the title compounds in the presence of MeONa as base, respectively. The approach affords the target compounds in acceptable‐to‐good yields. The new compounds were characterized by their IR, NMR, and HR mass spectra. 相似文献
12.
Pei‐Pei Jin Xue‐Cheng Liu De‐Qi Liu Zhi‐Bin Huang Da‐Qing Shi 《Journal of heterocyclic chemistry》2015,52(6):1625-1630
A series of chromeno[4,3‐d]isoxazolo[5,4‐b]pyridin‐6‐one derivatives were easily and efficiently synthesized by the reaction of 3‐acyl‐2H‐chromen‐2‐ones with isoxazol‐5‐amine in acetic acid. Some synthesized compounds were evaluated for their antiproliferative properties in vitro against cancer cells, and these compounds were found to have some activities. 相似文献
13.
Synthesis of Imidazo[2,1‐b][2H‐1,3,4]thiadiazines and 1,2,4‐Triazolo[3,4‐b][2H‐1,3,4]thiadiazines 下载免费PDF全文
Stefanie Knak Wolf‐Diethard Pfeiffer Horst Dollinger Ashot S. Saghyan Peter Langer 《Journal of heterocyclic chemistry》2015,52(2):463-467
Imidazo[2,1‐b][2H‐1,3,4]thiadiazines were prepared by cyclization of 2‐amino‐5‐(4‐chlorophenyl)‐6H‐1,3,4‐thiadiazine with α‐haloketones. 1,2,4‐Triazolo[3,4‐b][2H‐1,3,4]thiadiazines were prepared by cyclization of 4‐amino‐5‐sulfanyl‐l,2,4‐triazoles with phenacyl bromides. 相似文献
14.
An efficient one‐pot four‐component protocol for the synthesis of imidazo[1,2‐a]pyridines was developed by condensing ethane‐1,2‐diamine ( 2 ), 1,1‐bis(methylthio)‐2‐nitroethene ( 1 ), aldehydes 3 , and activated methylene compounds in EtOH under reflux conditions (Tables 1–3). The features of this procedure are operational simplicity, good yields of products, in situ preparation of heterocyclic ketene aminals (HKA), and catalyst‐free conditions. 相似文献
15.
Laleh Torkian Minoo Dabiri Peyman Salehi Morteza Bararjanian 《Helvetica chimica acta》2011,94(8):1416-1425
The 1‐{[(1H‐1,2,3‐Triazol‐4‐yl)methoxy]phenyl}‐1H‐pyrazolo[1,2‐b]phthalazine‐5,10‐dione derivatives 5 were synthesized by a simple and efficient method, i.e., by the four‐component, one‐pot condensation reaction of phthalohydrazide 4 , a (propargyloxy)benzaldehyde 1 , an active methylene compound 3 (malononitrile or ethyl cyanoacetate), and an azide 2 in the presence of Cu(OAc)2/sodium L ‐ascorbate as catalyst and 1‐methyl‐1H‐imidazolium trifluoroacetate ([Hmim](CF3COO)) as an ionic‐liquid medium in good to excellent yields (Scheme 1). 相似文献
16.
Synthesis of 1‐Amino‐5,6‐diaryl‐3‐cyano‐1H‐pyridin‐2‐ones and 6,7‐Diaryl‐4‐cyano‐3‐hydroxy‐1H‐[1,2]diazepines from Isoflavones 下载免费PDF全文
Mu‐Lin Zhu Zun‐Ting Zhang Dong Xue Hui‐Liang Hua Yong Liang Stanislaw F. Wnuk 《Helvetica chimica acta》2014,97(4):561-568
The one‐step cyclocondensation of substituted isoflavones (=3‐phenyl‐4H‐1‐benzopyran‐4‐ones) with cyanoacetohydrazide in the presence of KOH afforded a mixture of 1‐amino‐5,6‐diaryl‐3‐cyano‐1H‐2‐pyridin‐2‐ones and 6,7‐diaryl‐4‐cyano‐3‐hydroxy‐1H‐[1,2]diazepines. 相似文献
17.
A direct and efficient method for the conversion of alkyl aryl ketones to imidazo[1,2‐α]pyridines has been developed based on initial formation of α‐organosulfonyloxy ketones and their subsequent cyclocondensation by 2‐aminopyridines in one‐pot conditions. 相似文献
18.
Xianhai Tian Lina Song Manman Wang Zhigang Lv Dr. Jie Wu Dr. Wenquan Yu Prof. Dr. Junbiao Chang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(22):7617-7622
A novel and practical strategy for the construction of imidazo[1,2‐a]pyridin‐2‐amine frameworks has been developed. The present sequential approach involves addition of arylamines to nitriles and I2/KI‐mediated oxidative C?N bond formation without purification of the intermediate amidines. This operationally simple synthetic process provides a facile access to a variety of new 2‐amino substituted imidazo[1,2‐a]pyridines and related heterocyclic compounds in an efficient and scalable fashion. 相似文献
19.
Sambhaji P. Vartale Nilesh K. Halikar Shivraj B. Sirsat Yogesh D. Pawar 《Journal of heterocyclic chemistry》2013,50(2):351-354
Pyrazolo pyrimido pyrimidine ( 4a–k ) was prepared by the reaction of compound 3‐cyano‐4‐imino‐2‐(methylthio)4H‐pyrido[1,2‐a]pyrimidine ( 3 ) with hydrazine hydrate, phenyl hydrazine, 2‐hydrazino benzothiazole, and 6‐substituted hydrazine benzothiazole in N,N‐dimethylformamide and anhydrous potassium carbonate. These synthesized compounds were characterized by elemental analysis IR, 1H NMR, and mass spectral data. 相似文献