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1.
Salvatore Giandinoto Godwin O. Mbagwu Tamara A. Robinson Chantel Ferguson Jacqueline Nunez 《Journal of heterocyclic chemistry》1996,33(6):1839-1845
The synthesis of the first examples of Class II mesoionic xanthine acyclonucleosides is described. A series of mesoionic anhydro-(8-methoxyalkyl-5-hydroxy-7-oxothiazolo[3,2-a]pyrimidinium hydroxides), Class II mesoionic analogs isoconjugate with xanthine, were prepared by the thermal condensation of methoxyalkyl-2-aminothiazoles with substituted bis(2,4,6-trichlorophenyl)malonic esters. The memoxyalkyl-2-aminothiazoles were prepared via an aromatic nucleophilic substitution reaction between 2-bromothiazole and the appropriate methoxyalkylamine in excess. The resulting 8-methoxyalkyl-substituted mesoionic xanthines were demethylated using iodotrimethylsilane in acetonitrile at room temperature to afford the corresponding mesoionic anhydro-(8-hydroxyalkyl-5-hydroxy-7-oxothiazolo[3,2-a]pyrimidinium hydroxides) as the Class II mesoionic xanthine acyclonucleosides. 相似文献
2.
I. Forfar J. Guillon S. Massip J.‐M. Lger C. Jarry J.‐P. Fayet 《Journal of heterocyclic chemistry》2001,38(4):823-827
The isomeric 2‐substituted‐7(5)‐methyl‐2,3‐dihydro‐5(7)H‐oxazolo[3,2‐a]pyrimidin‐5‐ones 3a‐b and 7‐ones 2a‐b,7a were synthesized by cyclocondensation from the 5‐substituted‐2‐amino‐2‐oxazolines 1a‐b with biselectrophiles. In boiling ethanol, the reaction of 1a‐b with acetylenic esters led to a mixture of 2a‐b,7a with a small amount of (E)‐2‐N‐(2‐ethoxycarbonylethylene)‐5‐substituted‐2‐iminooxazolines 5a‐b . The ring annulation between 1a‐b and diketene gave the 2‐substituted‐7‐hydroxy‐7‐methyl‐2,3,6,7‐tetrahydro‐5H‐oxazolo[3,2‐ a ]pyrimidin‐5‐ones 4a‐b which can be easily dehydrated to provide the 2‐substituted‐7‐methyl‐2,3‐dihydro‐5H‐oxazolo[3,2‐a]pyrimidin‐5‐ones 3a‐b . 相似文献
3.
Thomas Kappe Peter Roschger Birgit Schuiki Wolfgang Stadlbauer 《Journal of heterocyclic chemistry》2003,40(2):297-302
2‐Methyl‐3H‐indoles 1 cyclize with two equivalents of ethyl malonate 2 to form 4‐hydroxy‐11H‐benzo[b]pyrano[3,2‐f]indolizin‐2,5‐diones 3, whereas 2‐mefhyl‐2,3‐dihydro‐1H‐indoles 9 give under similar conditions regioisomer 8‐hydroxy‐5‐methyl‐4,5‐dihydro‐pyrrolo[3,2,1‐ij]pyrano[3,2‐c]quinolin‐7,10‐diones 10 . The pyrone rings of 3 and 9 can be cleaved either by alkaline hydrolysis to give 7‐acetyl‐8‐hydroxy‐10H‐pyrido[1,2‐a]indol‐6‐ones 4 or 5‐acetyl‐6‐hydroxy‐2‐methyl‐1,2‐dihydro‐4H‐pyrrolo‐[3,2,1‐ij]quinolin‐4‐ones 11 , respectively. Chlorination of 3 and 9 with sulfurylchloride gives under subsequent ring opening 7‐dichloroacetyl‐8‐hydroxy‐10H‐pyrido[1,2‐a]indol‐6‐ones 5 or 5‐dichloracetyl‐6‐hydroxy‐2‐methyl‐1,2‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinolin‐4‐ones 12 . The dichloroacetyl group of 5 can be reduced with zinc to 7‐acetyl‐8‐hydroxy‐10H‐pyrido[1,2‐a]indol‐6‐ones 7. Treatment of the acetyl compounds 4, 7 and 11 with 90% sulfuric acid cleaves the acetyl group and yields 8‐hydroxy‐10H‐pyrido[1,2‐a]‐indol‐6‐ones 6 and 8 , and 6‐hydroxy‐2‐methyl‐1,2‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinolin‐4‐ones 13 . Reaction of dichloroacetyl compounds 12 with sodium azide yields 6‐hydroxy‐2‐methyl‐5‐(1H‐tetrazol‐5‐ylcarbonyl)‐1,2‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinolin‐4‐ones 14 via intermediate geminal diazides. 相似文献
4.
Yulin Ling Haochong Liu Aiting Zheng Guobin Li Xiaofang Li 《Journal of heterocyclic chemistry》2013,50(5):1009-1013
The reaction involving 4‐phenyl‐octahydro‐pyrano[2,3‐d]pyrimidine‐2‐thione, ethyl chloroacetate and the appropriate aromatic aldehyde yielded 2‐arylmethylidene‐5‐phenyl‐5a,7,8,9a‐tetrahydro‐5H,6H‐pyrano[2,3‐d][1,3]thiazolo[3,2‐a]pyrimidin‐3(2H)‐ones. The 1,3‐dipolar cycloaddition of 2‐arylmethylidene‐5‐phenyl‐5a,7,8,9a‐tetrahydro‐5H,6H‐pyrano[2,3‐d][1,3]thiazolo[3,2‐a]pyrimidin‐3(2H)‐ones with azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone afforded 4′‐aryl‐1′‐methyl‐5″‐phenyl‐5a″,7″,8″,9a″‐tetrahydro‐2H,5″H,6″H‐dispiro[acenaphthylene‐1,2′‐pyrrolidine‐3′,2″‐pyrano[2,3‐d][1,3]thiazolo[3,2‐a]pyrimidine]‐2,3″‐diones in moderate yields. The structures of the products were determined and characterized thoroughly by NMR, MS, IR, elemental analysis, and X‐ray crystallographic analysis. 相似文献
5.
Synthesis of Heteroannulated Chromeno[2,3‐b]Pyridines: DBU Catalyzed Reactions of 2‐Amino‐6‐methylchromone‐3‐Carboxaldehyde with Some Heterocyclic Enols and Enamines
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Magdy A. Ibrahim Nasser M. El‐Gohary Sara Said 《Journal of heterocyclic chemistry》2016,53(1):117-120
New series of heteroannulated chromeno[2,3‐b]pyridines were easily and efficiently synthesized from DBU‐catalyzed condensation of 2‐amino‐6‐methylchromone‐3‐carboxaldehyde with a variety of heterocyclic enols and enamines, namely, 4‐hydroxycoumarin, 4‐hydroxy‐1‐methylquinolin‐2(1H)‐one, 2‐hydroxy‐4H‐pyrido[1,2‐a]pyrimidin‐4‐one, 4‐hydroxy‐2H‐pyrano[3,2‐c]quinoline‐2,5(6H)‐dione, 4(6)‐aminouracil and 5‐amino‐3‐methyl‐1H‐pyrazole. Structures of the new synthesized products were deduced on the basis of their analytical and spectral data. 相似文献
6.
P. Vijay Kumar Reddy P. Naveen Kumar G. V. P. Chandramouli 《Journal of heterocyclic chemistry》2005,42(2):283-286
A variety of novel 6,6′‐arylidene‐bis‐[5‐hydroxy‐9‐methyl‐2,3‐diaryl‐thieno[3,2‐g]thiocoumarins] 3a‐d , 4a‐d , 5a‐d , and 6a‐d were obtained by a reaction between 5‐hydroxy‐9‐methyl‐2,3‐diarylthieno[3,2‐g]thiocoumarins 1a‐d with aromatic aldehydes 2a‐d in isopropyl alcohol. The synthesized compounds were tested for their antimicrobial activity. 相似文献
7.
The key intermediates allyloxyquinoxaline 2a–c and N‐allylquinoxaline 3a–c were used to synthesize a number of acyclonucleosides whose chemical modifications include quinoxaline ring and the acyclic part is either N1‐propanediol or 3‐hydroxy‐ propyl substituents and their O‐analogues. These compounds were characterized by elemental analysis, MALDI MS, and NMR data. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:280–288, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20203 相似文献
8.
A. A. F. Wasfy 《Heteroatom Chemistry》2003,14(7):576-580
4‐Allylthio‐2‐arylquinazolines 4a–c undergo cyclization by action of bromine to furnish 5‐aryl‐3‐bromomethyl‐2,3‐dihydrothiazolo[3,2‐c]quinazolin‐4‐ium bromides 5a–c . Compounds 5a–c undergo ring opening by action of water under acid catalysis to afford the corresponding dibromide derivatives 6a–c . Bromination of 3‐allyl‐2‐aryl‐4(3H)quinazolinethiones 7a–c leads to 5‐aryl‐2‐bromomethyl‐2,3‐dihydrothiazolo[3,2‐c]quinazolin‐4‐ium bromides 8a–c . However, anhydro‐3‐hydroxy‐5‐aryl‐1,3‐thiazolo[3,2‐c]quinazolin‐4‐ium hydroxide 10a–c were prepared by the cyclodehydration of the corresponding thioglycolic acids 9a–c with Ac2O. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:576–580, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10148 相似文献
9.
Essam Kh. Ahmed 《Heteroatom Chemistry》2003,14(3):201-207
Convenient syntheses of 3‐substituted ethyl 4‐oxo‐2‐thioxo‐1,2,3,4,5,6,7,8‐octahydropyrid[4′,3′:4,5]thieno[2,3‐d]pyrimidine‐7‐carboxylates 3a, b, 6, 11–13 , ethyl 3‐methyl‐5‐oxo‐2,3,6,9‐tetrahydro‐5 H‐pyrido[4′,3′:4,5]thieno[2,3‐d][1,3]thiazolo[3,2‐a]pyrimidine‐8‐7H‐carboxylate ( 4 ), and ethyl 2‐methyl‐5‐oxo‐2,3,6,9‐tetrahydro‐5H‐pyrido[4′,3′:4,5]thieno[2, 3‐d][1,3]thiazolo[3,2‐a]pyrimidine‐8[7H]carboxylate ( 8 ) from diethyl 2‐isothiocyanato‐4,5,6,7‐tetrahythieno[2,3‐c]pyridine‐3,6‐dicarboxylate ( 1 ) are reported. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:201–207, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10131 相似文献
10.
M.Iqbal Choudhary Irfan Baig M. Nur‐e‐Alam S. Shahzad‐ul‐Hussan Purev
ndognii M. Bunderya Z. Oyun Atta‐ur‐Rahman 《Helvetica chimica acta》2001,84(8):2409-2416
The four new and four known sesquiterpenoid derivatives 1 – 4 and 5 – 8 , respectively, were isolated from the air‐dried roots of Ferula mongolica. The structures of these compounds were determined by spectroscopic methods and found to be rel‐(2R,3R)‐2‐[(3E)‐4,8‐dimethylnona‐3,7‐dienyl]‐3,4‐dihydro‐3,8‐dihydroxy‐2‐methyl‐2H,5H‐pyrano[2,3‐b][1]benzopyran‐5‐one ( 1 ), rel‐(2R,3R)‐2‐[(3E)‐4,8‐dimethylnona‐3,7‐dienyl]‐2,3‐dihydro‐7‐hydroxy‐2,3‐dimethyl‐4H‐furo[2,3‐b][1]benzopyran‐4‐one ( 2 ), rel‐(2R,3R)‐2‐[(3E)‐4,8‐dimethylnona‐3,7‐dienyl]‐2,3‐dihydro‐7‐hydroxy‐2,3‐dimethyl‐4H‐furo[3,2‐c][1]benzopyran‐4‐one ( 3 ), rel‐(2R,3R)‐2‐[(3E)‐4,8‐dimethylnona‐3,7‐dienyl]‐2,3‐dihydro‐7‐methoxy‐2,3‐dimethyl‐4H‐furo[3,2‐c][1]benzopyran‐4‐one ( 4 ), (4E,8E)‐1‐(2‐hydroxy‐4‐methoxyphenyl)‐5,9,13‐trimethyltetradeca‐4,8,12‐trien‐1‐one ( 5 ), the rel‐(2R,3S) diastereoisomer 6 of 2 , the rel‐(2R,3S) diastereoisomer 7 of 4 , and (4E,8E)‐1‐(2,4‐dihydroxyphenyl)‐5,9,13‐trimethyltetradeca‐4,8,12‐trien‐1‐one ( 8 ). These compounds were tested as inhibitors against the enzyme α‐glucosidase. The compounds 1 – 6 and 8 exhibited significant inhibitory activity and, therefore, represent a new class of α‐glucosidase inhibitors. 相似文献
11.
《Journal of heterocyclic chemistry》2017,54(1):546-550
A simple and efficient method has been described for the synthesis of acetyl and iodo derivatives of 4‐hydroxy‐6‐phenyl‐6H‐pyrano[3,2‐c ]pyridine‐2,5‐diones 1 and 4‐hydroxy‐1‐phenylpyridin‐2(1H )‐ones 5 . Compounds 1 with phenyl and alkyl substituent at C(7) and C(8), respectively, can be easily acetylated by refluxing in a mixture of acetic acid and polyphosphoric acid to give 3‐acetyl‐4‐hydroxy‐6‐phenyl‐6H‐pyrano[3,2‐c ]pyridine‐2,5‐diones 2 in excellent yields. Compounds 1 and 5 can be iodinated with iodine and anhydrous sodium carbonate in boiling dioxane to give 4‐hydroxy‐3‐iodo‐6‐phenyl‐6H‐pyrano[3,2‐c ]pyridine‐2,5‐diones 3 and 4‐hydroxy‐3‐iodo‐1‐phenylpyridin‐2(1H )‐ones 6 , respectively, in good yields. The structures were confirmed using infrared, nuclear magnetic resonance , and elemental analysis. 相似文献
12.
Andrey N. Komogortsev Boris V. Lichitsky Alexander D. Tretyakov Artem N. Fakhrutdinov Arkady A. Dudinov Michail M. Krayushkin 《Journal of heterocyclic chemistry》2019,56(11):3081-3087
A convenient approach to the synthesis of the previously unknown 7H‐furo[3,2‐b]pyran‐7‐ones based on the intramolecular cyclization of carbonyl derivatives of 5‐hydroxy‐2‐methyl‐4H‐pyran‐4‐one has been elaborated. Key intermediates in the synthesis of the target 7H‐furo[3,2‐b]pyran‐7‐ones are 3‐hydroxy‐6‐methyl‐2‐(2‐oxo‐2‐arylethyl)‐4H‐pyran‐4‐ones. They are formed as a result of multicomponent condensation of 5‐hydroxy‐2‐methyl‐4H‐pyran‐4‐one with arylglyoxals and 4‐methoxyaniline. 相似文献
13.
2,3‐Dihydro‐4H‐thiopyrano[2,3‐b]pyridin‐4‐ones 4 were prepared by a three‐step sequence from commercially available 2‐chloropyridine ( 1 ). Thus, successive treatment of 1 with iPr2NLi (LDA) and α,β‐unsaturated aldehydes gave 1‐(2‐chloropyridin‐3‐yl)alk‐2‐en‐1‐ols 2 , which were oxidized with MnO2 to 1‐(2‐chloropyridin‐3‐yl)alk‐2‐en‐1‐ones 3 . The reactions of 3 with NaSH?n H2O proceeded smoothly at 0° in DMF to provide the desired thiopyranopyridinones. Similarly, 2,3‐dihydro‐4H‐thiopyrano[2,3‐c]pyridin‐4‐ones 8 and 2,3‐dihydro‐4H‐thiopyrano[3,2‐c]pyridin‐4‐ones 12 were obtained starting from 3‐chloropyridine ( 5 ) and 4‐chloropyridine ( 9 ), respectively. 相似文献
14.
Thomas Kappe Franz Frühwirth Peter Roschger Brigitte Jocham Jenny Kremsner Wolfgang Stadlbauer 《Journal of heterocyclic chemistry》2002,39(2):391-397
Cyclocondensation of 2,3,3‐trimefhyl‐3H‐indoles 2 with malonates 3 gives 8‐hydroxy‐10,10‐dimefhyl‐10H‐pyrido[1,2‐a]indol‐6‐ones 4 , which were halogenated in position 7, 8 and 9 with sulfuryl chloride, bromine or phosphoroxychloride to give the corresponding halo‐10,10‐dimethyl‐10H‐pyrido[1,2‐a]indoles 5, 6, 7 and 8 . Amination affords the 8‐amino‐10,10‐dimethyl‐10H‐pyrido[1,2‐a]indol‐6‐one 9 . Nitration gives either the 10,10‐dimethyl‐7‐nitro‐10H‐pyrido[1,2‐a]indoles 10 or 10,10‐dimethyl‐7‐hydroxy‐10H‐pyrido[1,2‐a]indoles 11 , depending on the conditions. 相似文献
15.
Akiko Hori Yasuhide Ishida Takahiro Kikuchi Kumiko Miyamoto Hiroshi Sakaguchi 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(12):o593-o597
In the crystal structure of 6‐phenyl‐3‐thioxo‐2,3,4,5‐tetrahydro‐1,2,4‐triazin‐5‐one, C9H7N3OS, (I), the 1,2,4‐triazine moieties are connected by face‐to‐face contacts through two kinds of double hydrogen bonds (N—H...O and N—H...S), which form planar ribbons along the a axis. The ribbons are crosslinked through C—H...π interactions between the phenyl rings. The molecular structures of two regioisomeric compounds, namely 6‐phenyl‐2,3‐dihydro‐7H‐1,3‐thiazolo[3,2‐b][1,2,4]triazin‐7‐one, C11H9N3OS, (II), and 3‐phenyl‐6,7‐dihydro‐4H‐1,3‐thiazolo[2,3‐c][1,2,4]triazin‐4‐one, C11H9N3OS, (III), which were prepared by the condensation reaction of (I) with 1,2‐dibromoethane, have been characterized by X‐ray crystallography and spectroscopic studies. The crystal structures of (II) and (III) both show two crystallographically independent molecules. While the two compounds are isomers, the unit‐cell parameters and crystal packing are quite different and (II) has a chiral crystal structure. 相似文献
16.
The novel 6‐ethyl‐4‐hydroxy‐2,5‐dioxo‐5,6‐dihydro‐2H‐pyrano[3,2‐c]quinoline‐3‐carboxaldehyde ( 2 ) was efficiently synthesized from Vilsmeier–Haack formylation of 3‐(1‐ethy1‐4‐hydroxy‐2‐oxo‐(1H)‐quinolin‐3‐yl)‐3‐oxopropanoic acid ( 1 ). The aldehyde 2 was allowed to react with some nitrogen nucleophiles producing a variety of hydrazones 3 – 7 . Reaction of aldehyde 2 with hydrazine hydrate and hydroxylamine hydrochloride afforded pyrazole and isoxazole annulated pyrano[3,2‐c]quinoline‐2,5(6H)‐dione, respectively. The reactivity of aldehyde 2 was examined toward some active methylene nitrile, namely, malononitrile, ethyl cyanoacetate, and cyanoacetamide leading to 2‐iminopyrano[2′,3′:4,5]pyrano[3,2‐c]quinolines 10 – 12 , respectively. Also, some novel pyrazolo[4″,3″:5′,6′]pyrano[2′,3′:4,5]pyrano[3,2‐c]quinolines ( 13 , 14 ) and thiazolo[5″,4″:5′,6′]pyrano[2′,3′:4,5]pyrano[3,2‐c]quinolines ( 15 , 16 ) were synthesized. Structures of the new synthesized products were deduced on the basis of their analytical and spectral data. 相似文献
17.
Mn(III)‐catalyzed Aerobic Oxidation of 3‐Alkyl‐4‐hydroxy‐1H‐pyrrol‐2(5H)‐ones in the Presence of 1,1‐Diarylethenes. Synthesis of Stable 8‐Aza‐1‐hydroxy‐2,3‐dioxabicyclo[4.3.0]nonan‐7‐one Framework
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Twenty‐two 3‐alkyl‐4‐hydroxy‐1H‐pyrrol‐2(5H)‐ones were prepared and underwent Mn(III)‐catalyzed aerobic oxidation in the presence of 1,1‐diarylethenes to produce very stable crystalline 6‐alkyl‐8‐aza‐4,4‐diaryl‐1‐hydroxy‐2,3‐dioxabicyclo[4.3.0]nonan‐7‐ones in high yields. 相似文献
18.
Gerardo Blanco Jos M. Quintela Carlos Peinador 《Journal of heterocyclic chemistry》2006,43(4):1051-1056
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
20.
Antony Bulanov Igor N. Shcherbakov Leonid D. Popov E. Y. Shasheva P. A. Belikov Zoya A. Starikova 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(3):o85-o88
The structures of new oxaindane spiropyrans derived from 7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐carbaldehyde (SP1), namely N‐benzyl‐2‐[(7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐yl)methylidene]hydrazinecarbothioamide, C27H25N3O3S, (I), at 120 (2) K, and N′‐[(7‐hydroxy‐3′,3′‐dimethyl‐3′H‐spiro[chromene‐2,1′‐isobenzofuran]‐8‐yl)methylidene]‐4‐methylbenzohydrazide acetone monosolvate, C27H24N2O4·C3H6O, (II), at 100 (2) K, are reported. The photochromically active Cspiro—O bond length in (I) is close to that in the parent compound (SP1), and in (II) it is shorter. In (I), centrosymmetric pairs of molecules are bound by two equivalent N—H...S hydrogen bonds, forming an eight‐membered ring with two donors and two acceptors. 相似文献