共查询到20条相似文献,搜索用时 78 毫秒
1.
Mehdi M. Baradarani Arash Afghan Farideh Zebarjadi Kamal Hasanzadeh John A. Joule 《Journal of heterocyclic chemistry》2006,43(6):1591-1595
2,3,3‐Trimethylindolenine and 5‐chloro‐2,3,3‐trimethylindolenine were converted into β‐diformyl compounds by the action of the Vilsmeier reagent at 50°C. The dialdehydes reacted with various arylhydrazines and 2‐pyridylhydrazine to produce mono‐hydrazones as mixtures of cis and trans isomers. Heating the hydrazones in refluxing ethanol produced 3,3‐dimethyl‐2‐(1‐aryl‐1H‐pyrazol‐4‐yl)‐3H‐indoles in excellent yields. Reaction of the β‐diformyl compounds with hydrazine itself led directly to 3,3‐dimethyl‐2‐(pyrazol‐4‐yl)‐3H‐indoles. 相似文献
2.
Regina Janciene Zita Stumbreviciute Daiva Podeniene Benedikta D. Puodziunaite Steve Black Stephen M. Husbands 《Journal of heterocyclic chemistry》2006,43(4):979-984
A number of substituted 4H,5H,6H‐thiazolo[3,2‐a][1,5]benzodiazepinium salts 2a‐h, 5, 9 , which are based on the novel thiazolobenzodiazepine system, were prepared by condensation‐cyclization of 1,5‐benzodiazepine‐2‐thiones 1a‐f, h, 4 with α‐haloketones, as well as with α‐bromoacetaldehyde diethyl acetal. The structure and stereochemistry of the ring system obtained were investigated by 1H and 13C nmr spectroscopy: the additional heterocyclic nucleus was found to appreciably influence the conformational mobility of the heptatomic ring. Upon treatment of salt 2d with alkali the presence of the base enamine structure in solution has been postulated. 相似文献
3.
The cyclocondensation reaction of compound 1 in boiling hydrochloric acid had an unexpected course. Instead of supposed 5,11‐dihydro‐quinoxalino[2,3‐b]quinoline 6a , 2‐(indol‐2‐yl)‐benzimidazole 4 was isolated as the major product. 相似文献
4.
A. K. El‐Shafie A. M. Soliman A. A. Sultan E. Abd‐Alla 《Journal of heterocyclic chemistry》2006,43(1):133-137
2(1‐Acetyl‐2‐oxopropylidene)naphtho[2,3‐d][1,3]dithiole‐4,9‐dione 1 reacts with a variety of bidentates reagents to give some new functionally substituted spiro naphthodithiole‐4,9‐dione derivatives. 相似文献
5.
Javad Azizian Farhad Hatamjafari Ali Reza Karimi 《Journal of heterocyclic chemistry》2006,43(5):1349-1352
A series of some new spiro‐1,4‐dihydropyridine derivatives have been synthesized in good yields in a four component, and solvent‐free process by condensation of isatins, primary amines, ethyl cyanoacetate and cyclohexanone on solid support montmorillonite K10 相似文献
6.
Shiv P. Singh Vinod Kumar Ranjana Aggarwal Jose Elguero 《Journal of heterocyclic chemistry》2006,43(4):1003-1014
We report the results obtained when five aromatic or heteroaromatic hydrazines react with six β‐diketones bearing trifluoromethyl and aryl substituents. Forty‐two compounds have been isolated corresponding to two isomeric trifluoromethyl pyrazoles and the intermediate 5‐CF3, 5‐OH pyrazolines. The results have provided useful information for establishing the mechanism of the synthesis of pyrazoles. 相似文献
7.
Sukanta Kamila Benjamin Koh Omair Khan Hongming Zhang Edward R. Biehl 《Journal of heterocyclic chemistry》2006,43(6):1641-1646
A series of 2‐alkyl/aryl‐4H‐benzo[1,4]thiazine‐3‐ones have been synthesized by microwave irradiation of ethyl‐2‐bromo‐2‐alkyl/aryl acetate and 2‐amino thiophenol in the presence of 1,8‐diazabicyclo‐[5.4.0] undec‐7‐ene and N‐methylpiperidine. All compounds were characterized by 1H NMR, 13C NMR and elemental analyses, and by X‐ray crystallography in the case of 2‐methyl‐4H‐benzo[1,4]thiazin‐3‐one. 相似文献
8.
Lucina Arias Hactor Salgado‐Zamora Elena Campos Alicia Reyes Humberto Cervantes Edward C. Taylor 《Journal of heterocyclic chemistry》2006,43(3):565-569
In some nucleophilic substitution reactions of 2‐cyano‐3‐nitroimidazo[1,2‐a]pyridine, nitrogen (alkylamines, guanidine) and oxygen nucleophiles (alkoxides) underwent substitution of the 2‐cyano group, while sulfur nucleophiles (alkylthiols) underwent substitution of the 3‐nitro group. 相似文献
9.
Sivaperuman Saravanan Arumugam Nithya Shanmugam Muthusubramanian 《Journal of heterocyclic chemistry》2006,43(1):149-155
The synthesis of a new set of selenadiazoles, 4‐aryl‐5‐(1‐aryl‐2‐methyl‐2‐nitropropyl)‐1,2,3‐selenadiazoles ( 4 ) derived from 2‐[4‐methyl‐4‐nitro‐1,3‐diarylpentylidene]‐1‐hydrazinecarboxamide ( 3 ) has been reported. THF has been found to be the solvent of choice for this reaction. Structural features of 3 and 4 have been analyzed by NMR and X‐ray techniques. 相似文献
10.
Milda M. Burbuliene Olegas Bobrovas Povilas Vainilavicius 《Journal of heterocyclic chemistry》2006,43(1):43-47
Treatment of ambident sodium salt of 2‐methylsulfanyl‐4(3H)‐quinazolinone with methyl bromoacetate resulted in N(3)‐alkyl ester formation. Reaction of the resulted ester with hydrazine hydrate gave 2‐methylsulfanyl‐4‐oxo‐3(4H)‐quinazolinyl)acetohydrazide, which underwent intramolecular cyclization under heating in dimethylformamide to give 1‐aminoimidazo[2,1‐b]quinazoline‐2,5(1H,3H)‐dione. The latter took place in acylation reaction and in condensation with aromatic aldehydes. 相似文献
11.
Yoshihisa Okamoto Yoshimi Yamaguchi Mitsuaki Maeda Yoshihisa Kurasawa 《Journal of heterocyclic chemistry》2008,45(3):717-721
Fused tetracycles, 6‐alkyl‐3‐alkoxy‐2‐cyano‐4,5,6a,11‐tetraazabenzo[a]fluorene derivatives ( 5a , b , c , d , e , f ), are synthesized from 2‐alkoxy‐5‐(benzimidazol‐2‐ylidene)‐3‐cyano‐6‐imino‐5,6‐dihydro‐pyridines ( 4b , c ), and when refluxed in ethyl orthoacetate or ethyl orthopropionate, the elecrophilic aromatic substitution occurs at the ortho position of the cyanopyridine ring in the fused tetracycles ( 5b , c , e , f ) to afford 6‐alkyl‐3‐alkoxy‐2‐cyano‐1‐ethyl‐4,5,6a,11‐tetraazabenzo[a]fluorenes( 6b , c , e , f ). 相似文献
12.
Qingqing Shao Shujiang Tu Chunmei Li Longji Cao Dianxiang Zhou Bo Jiang Yan Zhang Wenjuan Hao Qian Wang 《Journal of heterocyclic chemistry》2008,45(2):411-416
Triaza‐benzo[b]fluoren‐6‐one derivatives were synthesized via the three‐component reaction of aldehyde, cyclohexane‐1,3‐dione compound and 2‐aminobenzimidazole in water under microwave irradiation. The new protocol has the advantages of excellent yield, low cost, reduced environment impact, wide scope and convenient procedure. 相似文献
13.
A simple and environmental friendly microwave irradiation method is devised for the synthesis of derivatives of 1,3,4‐oxadiazoles viz., 6a‐e and 7h‐q in 75–90% yield. Structures of the newly synthesised compounds were confirmed by physical, analytical and spectral (ir, 1H and 13C nmr and ms) data and screened for antiinflammatory, anticonvulsant, antidiuretic and antihaemostatic activities. Some of the compounds have shown potent activities. 相似文献
14.
Mazaahir Kidwai Kavita Singhal Shweta Rastogi 《Journal of heterocyclic chemistry》2006,43(5):1231-1236
An expeditious and convenient solid supported synthesis of 1,3,7‐triaryl‐6‐phenyl‐2‐thioxo‐1,2,3,7‐tetrahydropyrrolo [2,3‐d]pyrimidin‐4‐one derivatives from readily accessible N,N‐disubstituted thiobarbituric acids under microwaves utilising Paal Knorr reaction is described. 相似文献
15.
Ramaiyan Manikannan Shanmugam Muthusubramanian 《Journal of heterocyclic chemistry》2008,45(4):1207-1210
Reaction of 2‐(5‐substituted‐2‐hydroxybenzylamino)phenols ( 2 ) with formalin in ethanol under reflux has chemoselectively led to 2‐(6‐substituted‐2H—benzo[e][1,3]oxazin‐3(4H)‐yl)phenols ( 3 ) in good yield involving the ring closure of the hydroxyl group of the C‐aryl ring and not that of the N‐aryl ring. 相似文献
16.
A simple one‐pot procedure for ring enlargement of α‐chloromethyl N‐containing heterocycles has been developed. By reaction of chloromethyl tetrahydroisoquinoline and its thieno analog with benzyl or allyl bromide under basic conditions, ring expansion and N‐substitution were achieved simultaneously. The key to the transformation was proposed to involve the formation of aziridinium salt and subsequent bond breaking between the nitrogen and tertiary carbon atoms. 相似文献
17.
Two competitive processes ‐ 1,3‐dipolar cycloaddition and nucleophilic addition ‐ in the reaction of 4,4,5,5‐tetramethyl‐4,5‐dihydro‐1H‐imidazole 3‐oxides with asymmetrically substituted alkynes were shown to occur. The influence of solvents and the nature of substituents in the reagent and substrate molecules on the rate ratio of these competitive processes were studied. 相似文献
18.
A simple one‐step method for preparation of novel 1,3,4‐triaryl‐3,4‐dihydropyrimidin‐2(1H)‐ones has been developed by reaction of aromatic isocyanates with β‐arylamino‐1‐phenylpropan‐1‐ones in refluxing toluene in the presence of KHSO4 and HCl. 相似文献
19.
Zhongjiao Ren Weiguo Cao Jie Chen Yu Wang Weiyu Ding 《Journal of heterocyclic chemistry》2006,43(2):495-497
A new process for synthesis of 5‐aryl‐3‐phenylpyrazole is achieved. The regioselective ring‐opening reaction of 2‐aryl‐3‐benzoyl‐1,1‐cyclopropanedicarbonitrile with hydrazine plays a crucial role in the described process. 相似文献
20.
The cyclocondensation of 5‐hydroxy‐pyrido[2,3‐d]pyrimidines 1 with malonates gives pyrano[2′,3′:4,5]‐pyrido[2,3‐d]pyrimidines 2 . Nitration of 1 and reduction with zinc in the presence of carboxylic acids/anhydrides gave 2‐alkyloxazolo[5′,4′:4,5]pyrido[2,3‐d]pyrimidines 4 , which were ring‐opened to 6‐aminopyrido[2,3‐d]pyrimidines 5, 6 and 7 . Cyclization of 6‐aminopyrido[2,3‐d]pyrimidines 6 with benzoylchlorides 8 gave 2‐aryloxazolo[5′,4′:4,5]pyrido[2,3‐d]pyrimidines 9 . Reaction conditions for the cyclization have been studied by differential scanning calorimetry (DSC). 相似文献