共查询到20条相似文献,搜索用时 15 毫秒
1.
Chittipaka Rajitha P. K. Dubey Venkataiah Sunku Venugopal Rao Veeramaneni Manojit Pal 《Journal of heterocyclic chemistry》2013,50(3):630-637
The synthesis of novel 1,2,3‐thiadiazol derivatives containing 2H‐benzo[b][1,4]oxazin‐3(4H)‐one moiety as one of the substituents has been reported. A combined application of H3PO4/(CF3CO)2O mediated acylation followed by Hurd–Mori reaction has been explored to synthesize these compounds. The scope and limitation of this strategy along with the reaction mechanism of the key step is discussed. 相似文献
2.
Ethan A. Wappes Stacy C. Fosu Trevor C. Chopko Prof. Dr. David A. Nagib 《Angewandte Chemie (International ed. in English)》2016,55(34):9974-9978
The Cδ?H amination of unactivated, secondary C?H bonds to form a broad range of functionalized pyrrolidines has been developed by a triiodide (I3?)‐mediated strategy. By in situ 1) oxidation of sodium iodide and 2) sequestration of the transiently generated iodine (I2) as I3?, this approach precludes undesired I2‐mediated decomposition which can otherwise limit synthetic utility to only weak C(sp3)?H bonds. The mechanism of this triiodide‐mediated cyclization of unbiased, secondary C(sp3)?H bonds, by either thermal or photolytic initiation, is supported by NMR and UV/Vis data, as well as intercepted intermediates. 相似文献
3.
The title compounds substituted 2‐lactosylthiothieno[2,3‐d]pyrimidin‐4‐ones 6 were synthesized by the glycosyl reaction and alcoholysis reaction of substituted 2‐thioxo‐thieno[2,3‐d]pyrimidin‐4‐ones 4 ,which is formed by the base catalytic and acetic acidify reaction of amino esters 2 with alkyl or arylisothiocyanates and hepta‐O‐acetyl‐lactosyl bromide in good yields. All of the compounds were confirmed by NMR, ESI‐MS, and elemental analysis. 相似文献
4.
Rasha S. Gouhar David S. A. Haneen Salwa M. El‐Hallouty 《Journal of heterocyclic chemistry》2019,56(5):1651-1660
A new series of quinazolinone derivatives bearing pyridine, pyrimidine, pyrazole, or pyran moieties were synthesized for the purpose of anticancer cell line evaluation. Synthesis of these derivatives was achieved by the reaction of the ketone 2 with the appropriate aldehydes in the presence of either ethylcyanoacetate or malononitrile and ammonium acetate in one‐pot reaction. Chalcones 6 reacted also with hydrazine hydrate to give the corresponding pyrazolines 7 and reacted with urea or thiourea to give the 2‐oxopyrimidines or the 2‐thioxopyrimidines 8 , respectively. Evaluation of some representative examples of the newly synthesized compounds against cancer cell lines showed promising activity as anticancer agents. 相似文献
5.
Jizhen Li Yuhua Mi Jianghua He Xuyang Luo Erkang Fan 《Journal of heterocyclic chemistry》2013,50(2):304-308
2‐Amino 3‐substituted‐quinazolin‐4(3H)‐one derivatives were synthesized from Pbf‐isothiocyanate and methyl anthranilate. The construction of the guanidine‐containing quinazolinone heterocyclic skeleton was achieved using Pbf‐activated thiourea treated with primary amines via iodine‐mediated guanidinylation. The desired compounds were obtained after Pbf cleavage by trifluoroacetic acid. 相似文献
6.
Preparation of Furo[3,2‐c]coumarins from 3‐Cinnamoyl‐4‐hydroxy‐2H‐chromen‐2‐ones and Acyl Chlorides: A Bu3P‐Mediated C‐Acylation/Cyclization Sequence 下载免费PDF全文
Chia‐Jui Lee Cheng‐Che Tsai Shao‐Hao Hong Geng‐Hua Chang Mei‐Chun Yang Dr. Lennart Möhlmann Prof. Dr. Wenwei Lin 《Angewandte Chemie (International ed. in English)》2015,54(29):8502-8505
A Bu3P‐mediated cyclization reaction of 3‐cinnamoyl‐4‐hydroxy‐2H‐chromen‐2‐ones though electrophilic addition of acyl chlorides towards the synthesis of highly functionalized furo[3,2‐c]coumarins bearing a phosphorus ylide moiety is described. These unprecedented cyclization reaction proceeds under mild reaction conditions within short reaction times (1 min to 1 h), and can be further applied in the synthesis of alkenyl‐substituted furo[3,2‐c]coumarins by the treatment with carbonyl electrophiles under basic conditions. 相似文献
7.
Agnieszka Bogdanowicz Henryk Foks Katarzyna Gobis Anna Kędzia Ewa Kwapisz Andrzej Olczak Marek L. Główka 《Journal of heterocyclic chemistry》2013,50(3):544-550
2‐Bromo‐4‐(pyrrolidin‐1‐yl)pyridine‐3‐carbonitrile obtained from 2‐(1,3‐bis(pyrrolidin‐1‐yl)allylidene)malononitrile has been used as a substrate for the synthesis of new cyanopyridine derivatives: 2‐methoxy, 2‐phenoxy, 2‐aminoethylthio, and 2‐thioxo. 4‐(Pyrrolidin‐1‐yl)‐2‐thioxo‐1,2‐dihydropyridine‐3‐carbonitrile 7 in reaction with suitable alkyl and aminoalkyl halides gave respective sulfides. All synthesized compounds were evaluated for their antimicrobial activity against 26 aerobic and anaerobic bacteria. Determined minimal inhibitory concentration values ranged from 6.2 to 100 µg/mL. Derivatives 1 , 3 , 4 , 6 , and 12 were the most active compounds. 相似文献
8.
Reaction of 4H‐pyrimido[2,1‐b]benzothiazole‐2‐thiomethyl‐3‐cyano‐4‐one (1) with hydrazine hydrate/aryl hydrazine/heteryl hydrazine in the presence of anhydrous potassium carbonate and dimethyl formamide afforded 3‐amino‐4‐oxo‐(2H)/aryl/heteryl pyrazolo[3′,4′:4,5]pyrimido[2,1‐b]benzothiazoles in good yield. These pyrazole derivatives on diazotization followed by replacement with hydroxy, chloro, bromo, iodo and on reduction gave the corresponding 3‐substituted derivatives. 相似文献
9.
10.
H. H. Abdel‐Razik 《中国化学会会志》2005,52(1):141-148
Several quinazoline‐2(1H),4(3H)‐dione derivatives were synthesized from pyrimidine‐2(1H),4(3H)‐dione derivative. 相似文献
11.
Bijin Li Brianna Lawrence Guigen Li Haibo Ge 《Angewandte Chemie (International ed. in English)》2020,59(8):3078-3082
The first example of PdII‐catalyzed γ‐C(sp3)?H functionalization of aliphatic and benzoheteroaryl aldehydes has been developed using a transient ligand and an external ligand, concurrently. A wide array of γ‐arylated aldehydes were readily accessed without preinstalling internal directing groups. The catalytic mechanism was studied by performing deuterium‐labelling experiments, which indicated that the γ‐C(sp3)?H bond cleavage is the rate‐limiting step during the reaction process. This reaction could be performed on a gram scale, and also demonstrated its potential application in the synthesis of new mechanofluorochromic materials with blue‐shifted mechanochromic properties. 相似文献
12.
Pd/C‐Mediated Alkynylation of Indazoles: Synthesis and Pharmacological Evaluation of Mono and Dialkynyl‐Substituted Indazoles 下载免费PDF全文
D. R. Gorja K. Shiva Kumar B. Dulla K. Mukkanti M. Pal 《Journal of heterocyclic chemistry》2014,51(2):374-382
The combination of Pd/C–CuI–PPh3 has been identified as an efficient catalytic system for the C–C bond formation between 6‐bromo‐3‐iodo‐1H‐indazole and terminal alkynes in ethanol. Mono and/or dialkynyl‐substituted indazoles can be prepared using this general and practical methodology in good to excellent yields. Some of the compounds synthesized were tested for cytotoxic activities in vitro. 相似文献
13.
Synthesis of novel 4-(4-methylsulfonylphenyl)-3-phenyl-2(3H)-thiazole thione derivatives with functionalized diarylheterocycle pharmacophore as potential COX-2 inhibitors was described. The title compounds were synthesized by cyclocondensation of corresponding dithiocarbamate and 2-bromo-1-(4-methylsulfonylphenyl)ethanone, followed by dehydration with H2SO4. All of the target compounds were characterized by ^1H NMR, IR and mass spectral data. 相似文献
14.
Ali A. Mohammadi Hamed Rohi Ali Abolhasani Soorki 《Journal of heterocyclic chemistry》2013,50(5):1129-1133
An efficient synthesis of novel 2‐aryl‐3‐(phenylamino)‐2,3‐dihydroquinazolin‐4(1H)‐one derivatives using KAl(SO4)2.12H2O (Alum) as a catalyst from an aldehyde and 2‐amino‐N‐phenylbenzohydrazine in ethanol is described. All synthesized derivatives were screened for anti‐bacterial activity. Some compounds exhibited promising anti‐bacterial activity with reference to standard antibiotics. 相似文献
15.
Palladium‐Catalyzed C−H Arylation of α,β‐Unsaturated Imines: Catalyst‐Controlled Synthesis of Enamine and Allylic Amine Derivatives 下载免费PDF全文
Minyan Li Dr. María González‐Esguevillas Dr. Simon Berritt Prof. Xiaodong Yang Dr. Ana Bellomo Prof. Dr. Patrick J. Walsh 《Angewandte Chemie (International ed. in English)》2016,55(8):2825-2829
A unique chemo‐ and regioselective α‐ and γ‐arylation of palladium azapentadienyl intermediates is presented. Two distinct catalysts and sets of conditions successfully controlled the regioselectivity of the arylation. These methods provide the first umpolung C?H functionalization of azapentadienyl palladium intermediates and enable the divergent synthesis of allylic amine and enamine derivatives, which are of significant interest in the pharmaceutical industry. 相似文献
16.
《Journal of heterocyclic chemistry》2017,54(1):35-43
A new series compounds of quinoline derivatives were synthesized by reaction of 3‐(carboxymethyl)‐2‐arylquinoline‐4‐carboxylic acids 1a , 1b , 1c with different nucleophiles. The structures of the new compounds were elucidated on the basis of FTIR, 1H‐NMR, 13C‐NMR spectral data, GC/MS, and chemical analysis. Investigation of antimicrobial activity of all new compounds was evaluated using a broth dilution technique in terms of minimal inhibitory concentration count against four pathogenic bacteria and two pathogenic fungi. Most of the new compounds were significantly active against bacteria and fungi. 相似文献
17.
Pyrazolone, Isoxazolone, Pyrimidinone, Pyrimidinothione, thiazolidinone and β‐lactam incorporating 2‐oximino benzpyrid‐4‐one derivatives have been synthesized by cyclocondensation addition reaction and cycloaddition of hydrazine hydrate, phenyl hydrazine, hydroxylamine, urea, thiourea, mercapto acetic acid, and chloroacetylchloride, respectively. 相似文献
18.
Dr. Sophie Colombel Dr. Nathalie Van Hijfte Dr. Thomas Poisson Dr. Eric Leclerc Prof. Dr. Xavier Pannecoucke 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(38):12778-12787
A new method for the synthesis of fluorinated α‐C‐glycosides is described. The reactions between highly electrophilic radicals (fluorinated or unfluorinated) and a 2‐benzyloxyglucal or galactal provide 2‐keto‐D ‐arabino‐ or 2‐keto‐D ‐lyxo‐hexopyranosides through an addition/fragmentation process. Sodium borohydride mediated or Meerwein–Ponndorf–Verley (MPV) reduction of these compounds provides α‐C‐glycosides that feature appropriate anchoring groups for further synthetic elaboration. The presence of CF2CO2iPr or CF2Br groups at the pseudo‐anomeric position allows efficient reduction/olefination or Br/Li‐exchange/nucleophilic‐addition sequences. These transformations open the way for the synthesis of fluorinated C‐glycosidic analogues of glycoconjugates. 相似文献
19.
The cyclization of aryl ketone anilides 3 with diethyl malonate to affords 4‐hydroxy‐6‐phenyl‐6H‐pyrano[3,2‐c]‐pyridin‐2,5‐diones 4 in good yields. 3‐Acetyl‐4‐hydroxy‐1‐phenylpyridin‐2(1H)‐ones 5 are obtained by ring‐opening reaction of 4‐hydroxy‐6‐phenyl‐6H‐pyrano[3,2‐c]‐pyridin‐2,5‐diones 4 in the presence of 1,2‐diethylene glycol. The reaction of 3‐acetyl‐4‐hydroxy‐1‐phenylpyridin‐2(1H)‐ones 5 with hydroxylamine hydrochloride produces 4‐hydroxy‐3‐[N‐hydroxyethanimidoyl]‐1‐phenylpyridin‐2(1H)‐ones 6 from which 3‐alkyloxyiminoacetyl‐4‐hydroxy‐1‐phenylpyridin‐2(1H)‐ones 7 are obtained by reacting with alkyl bromides or iodides in the presence of anhydrous potassium carbonate with moderate yields. The similar compounds can be synthesized on refluxing 3‐acetyl‐4‐hydroxy‐1‐phenylpyridin‐2(1H)‐ones 5 with substituted hydroxylamine hydrochloride in the presence of sodium bicarbonate with good yields. Most of the synthesized compounds are characterized by IR and NMR spectroscopic methods. 相似文献