共查询到20条相似文献,搜索用时 15 毫秒
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Saleh M. Al‐Mousawi Mohammad A. Mohammad Mohamad H. Elnagdi 《Journal of heterocyclic chemistry》2001,38(4):989-991
While 3(5)‐aminopyrazole reacts with enaminonitrile to yield pyrazolo[1,5‐a]pyrimidines, 3‐amino‐5‐pyrazolone reacts with the same reagents to yields pyrazolo[3,4‐b]pyridines. 相似文献
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The Chemistry and application of the title aldehyde and some simple derivatives thereof are reviewed. 相似文献
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A facile, solvent free, ecofriendly approach for the synthesis of 2‐amino‐3(ethylcarboxy)‐4,6‐disubsti‐tuted pyridine 4 and pyrazolo[3,4‐b]pyridines 6 is herein described employing neat reaction conditions under microwave irradiation. This solventless methodology is environmentally benign as it completely eliminates the use of solvent from the reaction procedure. The observed reaction rate enhancement and high yield of products are due to the neat reaction conditions coupled with microwaves (MWs). 相似文献
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Mahmoud A. Mohamed 《Journal of heterocyclic chemistry》2012,49(1):200-203
Cyclocondensation of cyanoacetamide and cyanothioacetamide with sodium salt of 3‐hydroxy‐1‐(pyridin‐3‐yl)prop‐2‐en‐1‐one gave 6‐oxo‐[2,3′]bipyridine 5a and 6‐thioxo‐[2,3′]bipyridine 5b derivatives, respectively. Compound 5b upon treatment with different methylenes 8 gave thieno[2,3‐b]pyridines 10 . Treatment of 5b with iodomethane gave bipyridine derivative 7 , which cyclocondensed with hydrazines 11 to give pyrazolo[3,4‐b]pyridines 13 . J. Heterocyclic Chem., (2012). 相似文献
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The synthesis and characterization of a number of 3-aryl-6H-isoxazolo[3,4-d]pyrazolo[3,4-b]pyridines and 3-aryl-6H-isoxazolo[5,4-d]pyrazolo[3,4–6]pyridines from common precursors, 5-benzoyl-4-chloro-1H-pyrazolo-[3,4-b]pyridines, has been described. The structures were determined by unambiguous chemical synthesis and by isolation and 13C nmr analysis of some key, isolated, intermediates. The ability of these compounds to displace [3H]flunitrazepam from CNS binding sites was also observed. 相似文献
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《Journal of heterocyclic chemistry》2017,54(4):2434-2439
A domino three‐component strategy with high efficiency for the synthesis of spiro[indoline‐3,4′‐pyrazolo[3,4‐b ]pyridines] from easily available isatins, pyrazol‐5‐amines and β‐ketonitriles under microwave heating. During reaction process, HOAc plays dual roles as reaction media as well as a Brønsted acid‐promoter. Flexible structural modification, broad functional group compatibility and mild reaction conditions make this strategy a useful and attractive process of library generation for drug discovery. 相似文献
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Heating of 1′‐(N‐substituted carbamoyl)methylspiro[2H‐1‐benzopyran‐2,2′‐[2H]indoles] with potassium hydroxide in ethanol yields diastereomeric 5a,13‐methano‐6H‐1,3‐benzoxazepino[3,2‐a]indole‐12‐carbox‐amides. Reduction of the latter with sodium borohydride affords 1,2,3,9a‐tetrahydro‐2‐hydroxyaryl‐9H‐pyrrolo[ 1,2‐a] indole‐3 ‐carboxamides. 相似文献
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Tholappanavara H. Suresha Kumara Gopalpur Nagendrappa Nanjappa Chandrika Haliwana B. V. Sowmya Manpreet Kaur Jerry P. Jasinski Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2016,72(9):670-678
Hydrazone derivatives exhibit a wide range of biological activities, while pyrazolo[3,4‐b]quinoline derivatives, on the other hand, exhibit both antimicrobial and antiviral activity, so that all new derivatives in these chemical classes are potentially of value. Dry grinding of a mixture of 2‐chloroquinoline‐3‐carbaldehyde and 4‐methylphenylhydrazinium chloride gives (E)‐1‐[(2‐chloroquinolin‐3‐yl)methylidene]‐2‐(4‐methylphenyl)hydrazine, C17H14ClN3, (I), while the same regents in methanol in the presence of sodium cyanoborohydride give 1‐(4‐methylphenyl)‐4,9‐dihydro‐1H‐pyrazolo[3,4‐b]quinoline, C17H15N3, (II). The reactions between phenylhydrazinium chloride and either 2‐chloroquinoline‐3‐carbaldehyde or 2‐chloro‐6‐methylquinoline‐3‐carbaldehyde give, respectively, 1‐phenyl‐1H‐pyrazolo[3,4‐b]quinoline, C16H11N3, (III), which crystallizes in the space group Pbcn as a nonmerohedral twin having Z′ = 3, or 6‐methyl‐1‐phenyl‐1H‐pyrazolo[3,4‐b]quinoline, C17H13N3, (IV), which crystallizes in the space group R. The molecules of compound (I) are linked into sheets by a combination of N—H…N and C—H…π(arene) hydrogen bonds, and the molecules of compound (II) are linked by a combination of N—H…N and C—H…π(arene) hydrogen bonds to form a chain of rings. In the structure of compound (III), one of the three independent molecules forms chains generated by C—H…π(arene) hydrogen bonds, with a second type of molecule linked to the chains by a second C—H…π(arene) hydrogen bond and the third type of molecule linked to the chain by multiple π–π stacking interactions. A single C—H…π(arene) hydrogen bond links the molecules of compound (IV) into cyclic centrosymmetric hexamers having (S6) symmetry, which are themselves linked into a three‐dimensional array by π–π stacking interactions. 相似文献
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Moustafa A. Gouda 《Journal of heterocyclic chemistry》2011,48(1):1-10
This review describe the synthesis and reactions of 3‐amino‐4,6‐dimethyl‐1H‐pyrazolo[3,4‐b]pyridine as building block for the synthesis of polyfunctionalized heterocyclic compounds with pharmacological interest. J. Heterocyclic Chem., 2011. 相似文献
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Madhukar N. Jachak Sandeep M. Bagul Muddassar A. Kazi Raghunath B. Toche 《Journal of heterocyclic chemistry》2011,48(2):295-300
Novel pyrazolo[3,4‐h][1,6]naphthyridine derivatives 6 , 8 , 9 , 11 , 13 , and 15 have been synthesized by Friedlander condensation of new 4‐amino‐3‐methyl‐1‐phenyl‐1H‐pyrazolo[3,4‐b]pyridine‐5‐carbaldehyde (o‐aminoaldehyde) 4 with active methylene ketones, such as symmetric acetone 5a , monoalkylketones 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , unsymmetrical dialkyl ketones 7a , 7b , p‐bromophenylacetonitrile 10 , β‐ketoester 12a , β‐ketoamide 12b , or diethyl malonate 14 , respectively. J. Heterocyclic Chem., (2011). 相似文献
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Andrei A. Tolmachev Sergei I. Dovgopoly Aleksandr N. Kostyuk Ernest S. Kozlov Aleksei O. Pushechnikov Wolfgang Holzer 《Heteroatom Chemistry》1999,10(5):391-398
1,3,3‐Trimethyl‐2‐(1‐R‐3‐methyl‐5‐pyrazolyliminoethylidene)indolines were shown to undergo phosphorylation with phosphorus(III) halides at the two nucleophilic carbon centers to give fused 1,4‐azaphosphinine ring systems. Chemical properties of the synthesized compounds were characterized. For some representative compounds, detailed NMR spectroscopic investigations were performed, including the determination of 31P, 1H and 31P, 13C coupling constants. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 391–398, 1999 相似文献
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Kamlakar Avasthi Diwan S. Rawat Sanjay Sarkhel Prakas R. Maulik 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):o325-o327
The title compound, 6‐methylsulfanyl‐1‐(3‐phenylpropyl)‐4,5‐dihydro‐1H‐pyrazolo[3,4‐d]pyrimidin‐4‐one, C15H16N4OS, crystallizes in space group Pbca, with two molecules of similar structure in the asymmetric unit. The molecular structure shows the absence of intramolecular stacking in the crystalline state, as indicated by earlier 1H NMR analysis in solution. In addition, the crystal packing reveals the formation of a layered structure, due mainly to intermolecular N—H?O=C hydrogen bonding and arene–arene interactions. 相似文献
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A new method to obtain pyrazoloazines has been developped from the reaction between acetic anhydride or benzoyl chloride and 1,3-dimethyl-5-aminopyrazole. The structure of the new products has been established and an explanation for their origine has been proposed. 相似文献
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Ftima C. Teixeira Carla Lucas M. Joo M. Curto Antnio P. S. Teixeira M. Teresa Duarte Vnia Andr 《Heteroatom Chemistry》2016,27(1):3-11
Novel tetraethyl ethylene‐1,1‐bisphosphonate esters derived from 1H‐indazole, 1H‐pyrazolo[3,4‐b]pyridine, and 1H‐pyrazolo[3,4‐b]quinoline were synthesized by a Michael addition reaction of tetraethyl ethylidene‐1,1‐bisphosphonate with the corresponding heterocycle, using conventional heating and microwave‐assisted methods. The microwave‐assisted method provides shorter reaction times and better yields. The hydrolysis of bisphosphonates afforded the corresponding bisphosphonic acids or salt, using concentrated hydrochloric acid or TMSBr/collidine, respectively. All new compounds were fully characterized, and their structures were assigned using 1H, 31P, and 13C NMR and IR spectroscopies and mass spectrometry. The molecular structure of compound 6 was confirmed by X‐ray diffraction studies. 相似文献
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Madhukar N. Jachak Appasaheb B. Avhale Chanda D. Tantak Raghunath B. Toche Claudia Reidlinger Wolfgang Stadlbauer 《Journal of heterocyclic chemistry》2005,42(7):1311-1319
A series of 1,3,6‐trisubstituted and 1,3,5,6‐tetrasubstituted pyrazolo[3,4‐b]pyridines 5 has been synthesized by Friedlander condensation of 5‐arninopyrazole‐4‐carbaldehydes 3 with α‐methylene ketones such as acetone (4a) or acetophenones 4b‐f with potassium hydroxide as basic catalyst. Condensation of 5‐aminopyrazole‐4‐carbaldehydes 3 and unsymmetric dialkylketones 6 yielded mixtures of isomeric pyra‐zolo[3,4‐b]pyridine derivatives 7 and 8 . Condensation of 5‐aminopyrazole‐4‐carbaldehydes 3 with CH‐acidic acylacetonitriles 9 and acylacetates 11 with piperidine as basic catalyst yielded pyrazolo[3,4‐b]pyri‐dine‐5‐carbonitriles 10 and pyrazolo[3,4‐b]pyridine‐5‐carboxylates 12 ; with diethyl malonate 13 as CH‐acidic component, pyrazolo[3,4‐b]pyridin‐6‐ones 14 were obtained. 相似文献
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The title aldehyde 1 reacts smoothly with the enamine moiety of 2 ‐aminochromone 2 to produce hitherto unreported 3‐(2‐hydroxybenzoyl)‐5H‐1‐benzopyrano[2,3‐b]pyridin‐5‐one (azaxanthone) 5 . This reaction has been extended for the synthesis of bisazaxanthone 9. 相似文献