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Gbor Berecz Jzsef Reiter Gyula Argay Alajos Klmn 《Journal of heterocyclic chemistry》2002,39(2):319-325
Dedicated to Dr. János Császár on the occasion of his 70th birthday Ring transformation of 2‐cyanoimido‐3‐methyl‐1,3‐oxazolidine ( 10 ) yielded 5‐amino‐3‐[N‐(2‐hydrox‐yethyl)‐N‐methyl]amino‐1H‐1,2,4‐triazole ( 6 ) that was ring closed with different β‐keto esters to 2‐[N‐(2‐hydroxyethyl)‐N‐methyl]amino‐1,2,4‐triazolo[1,5‐a]pyrimidinones ( 4 ). Cyclisation of derivatives 4 led to imidazo[2′,1′:3,4][1,2,4]triazolo[1,5‐a]pyrimidines ( 2 ) and imidazo[1′,2′:2,3][1,2,4]triazolo[1,5‐a]pyrim‐idines ( 3 ) representing 10 novel ring systems. Besides spectroscopical evidence of structure of derivatives 2 and 3 X‐ray diffraction analysis of derivative 2b was also performed. 相似文献
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《Journal of heterocyclic chemistry》2018,55(2):545-550
A novel imidazo[4′,5′:3,4]pyrazolo[5,1‐c][1,2,4]triazine‐4,8‐dione heterocyclic system was synthesized starting from available 4‐amino‐6‐tert‐butyl‐3‐methylthio‐1,2,4‐triazin‐5(4H)‐one in four steps with 28% overall yield. 相似文献
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Synthesis of Pyrido[2′,3′: 3,4]pyrazolo[1,5‐a]pyrimidine,Pyrido[2′,3′:3,4]pyrazolo[5,1‐c][1,2,4]triazine,and Pyrazolyl Oxadiazolylthieno[2,3‐b]pyridine Derivatives 下载免费PDF全文
Nora M. Rateb 《Journal of heterocyclic chemistry》2014,51(5):1349-1356
6‐(2‐Thienyl)‐4‐(trifluoromethyl)‐1H‐pyrazolo[3,4‐b]pyridine‐3‐amine reacted with different active methylene compounds to afford pyridopyrazolopyrimidine derivatives. On the other hand, it reacted with some halo compounds to give the imidazo[1′,2′:1,5]pyrazolo[3,4‐b]pyridine derivatives. Also, it diazotized to give the corresponding diazonium chloride that is coupled with several active methylene compounds to give the corresponding triazine derivatives. Furthermore, compound 3‐amino‐6‐(2(thienyl)‐4‐(trifluoromethyl)thieno[2,3‐b]pyridine‐2‐carbohydrazide reacted with some β‐dicarbonyl compounds and some sulfur‐containing compounds to afford the corresponding pyrazolyl oxadiazolylthieno[2,3‐b]pyridine derivatives. 相似文献
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Anton V. Dolzhenko Shiqi Bai Anna V. Dolzhenko Wai Keung Chui 《Journal of heterocyclic chemistry》2012,49(4):763-767
A new convenient synthon for heterocyclic chemistry, namely 1H‐pyrazolo[3,4‐b]pyridin‐3‐ylguanidine was successfully prepared by selective guanylation of 1H‐pyrazolo[3,4‐b]pyridin‐3‐amine. A series of 3,4‐dihydropyrido[2′,3′:3,4]pyrazolo[1,5‐a][1,3,5]triazin‐2‐amines was synthesized from 1H‐pyrazolo[3,4‐b]pyridin‐3‐ylguanidine using aldehydes or ketones as one‐carbon inserting reagents. The tautomeric preferences of the products were determined using spectroscopic (e.g., 2D NOESY NMR) and single crystal X‐ray diffraction data. 相似文献
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Synthesis of Oxazolo[5,4‐d][1,2,4]triazolo[4,3‐a]pyrimidines as a New Class of Heterocyclic Compounds 下载免费PDF全文
Marzieh Akbarzadeh Mehdi Bakavoli Hossein Eshghi Ali Shiri 《Journal of heterocyclic chemistry》2016,53(3):832-839
Several new derivatives of oxazolo[5,4‐d]pyrimidine ( 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h ) have been synthesized through the reaction of 2,4‐dichloro‐6‐methyl‐5‐nitropyrimidine ( 2 ) with aryl carboxylic acids in refluxing POCl3. Further treatment of compounds ( 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h ) with hydrazine hydrate gave the hydrazine derivatives ( 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h ) that were subsequently cyclized into a novel heterocyclic system, oxazolo[5,4‐d][1,2,4]triazolo[4,3‐a]pyrimidine ( 5a , 5b , 5c , 5d , 5e , 5f , 5g , 5h , 5i , 5j , 5k , 5l , 5m , 5n , 5o , 5p ) and ( 7a , 7b , 7c , 7d ) on treatment with triethylorthoesters or carbondisulfide and alkylhalides, respectively. 相似文献
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Regioselective Synthesis of Some New Pyrazolo[1,5‐a]pyrimidines,Pyrazolo[1,5‐a]quinazoline and Pyrimido[4′,5′:3,4]pyrazolo[1,5‐a] pyrimidines Containing Thiazole Moiety 下载免费PDF全文
Samir Bondock Abd El‐Gaber Tarhoni Ahmed A. Fadda 《Journal of heterocyclic chemistry》2015,52(6):1792-1799
A regioselective synthesis of novel pyrazolo[1,5‐a]pyrimidines, pyrazolo[1,5‐a]quinazoline and pyrimido[4′,5′:3,4]pyrazolo[1,5‐a]pyrimidines incorporating a thiazole moiety was described via the reactions of the versatile, readily accessible 5‐amino‐3‐(phenylamino)‐N‐(4‐phenylthiazol‐2‐yl)‐1H‐pyrazole‐4‐carboxamide 3 with appropriate 1,3‐biselectrophilic reagents namely, β‐diketones, enaminones, and α,β‐unsaturated cyclic ketone. The newly synthesized compounds were elucidated by elemental analysis, spectral data, and alternative synthetic route whenever possible. 相似文献
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2-Thioxo-1,2-dihydropyridine derivatives 2a, 2b were reacted with methyl iodide to give 2-methylthiopyridines 3a, 3b, which were reacted with hydrazine hydrate to produce 3-aminopyrazolo[5,4-b]pyridines 4a, 4b. Compounds 4a, 4b were diazotized to afford the corresponding diazonium salts 5a, 5b, which were reacted with some active methylene compounds 6a-6h to give the corresponding pyrido[2′,3′ : 3,4]pyrazole[5,1-c][1,2,4]triazines 7-14. 相似文献
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Maria Rosaria Del Giudice Anna Borioni Carlo Mustazza Franco Gatta 《Journal of heterocyclic chemistry》1994,31(6):1503-1507
A number of 2-aryl-substituted pyrido[3,2-e] and [4,3-e][1,2,4]triazolo[1,5-c]pyrimidines and [1,2,4]triazolo[1,5-c]pteridines 11,12a,b,e , their corresponding 5-carbonyl derivatives 7,8a,b,e and some pyrimido[5,4-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ones 7,8c,d have been synthesized, according to different pathways. The new tricyclic heterocycles were prepared with the aim of studying their possible benzodiazepine receptors affinity. 相似文献
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Yoshihisa Kurasawa Mari Okiyama Yumiko Kamigaki Megumi Kanoh Yoshihisa Okamoto Atsushi Takada 《Journal of heterocyclic chemistry》1987,24(6):1805-1807
Novel pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6-b][1,5]benzoxazepines 5, 6 and 8 were synthesized, and these compounds were converted into novel spiro[benzoxazole-2′,4(1H,3′H)-pyrazolo[5,1-c][1,2,4]triazines] 7 and 9 by ring transformation. 相似文献
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Salo Gronowitz Ecaterina Temciuc Anna-Britta Hrnfeldt 《Journal of heterocyclic chemistry》1994,31(1):167-171
Halogen-metal exchange of 1,3-dibromodithieno[3,4-b:3′,2′-d]pyridine with butyllithium under different conditions has been studied. Upon reaction with iodine, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl carbonate, dimethyl disulfide and thiuram disulfide, the 1,3-diiodo-, 1,3-diacetyl-, 1,3-diformyl-, 1,3-dicarbomethoxy, 1,3-di(thiomethyl)- and 1,3-di(N,N-dimethyldithiocarbamoyl)dithieno[3,4-b:3′,2′-d]-pyridines, respectively, were obtained in varying yields. 3-Monosubstituted derivatives were obtained in some cases. The formation of 3,7-disubstituted derivatives was sometimes also observed. 相似文献
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Giorgio Roma Aldo Ermili Alessandro Balbi Elda Massa Mario Di Braccio 《Journal of heterocyclic chemistry》1981,18(8):1619-1623
The reaction of 3-(dimethylamino)-1-oxo-1H-naphtho[2,1-b]pyran-2-carbaldehyde (Ia) with o-phenylenediamines or N-monosubstituted o-phenylenediamines in refluxing glacial acetic acid afforded the corresponding naphtho[1′,2′:5,6]pyrano[2,3-b][1,5]benzodiazepin-15-(8H)ones V in very good yields. A similar result was achieved when the reaction was carried out in refluxing pyridine, using N-monosubstituted o-phenylenediamine hydrochlorides. The isolation of a significant intermediate as well as the synthesis through a different univocal pathway confirmed the structure of the compounds V. Moreover the reaction of Ia with N-monosubstituted o-phenylenediamines in refluxing pyridine generally afforded only low yields of compounds V, sometimes together with naphtho[1′,2′:5,6]pyrano[2,3-b][1,5]benzodiazepin-15-(13H)ones VII, isomers of V. 相似文献
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Yoshihisa Kurasawa Megumi Kanoh Yumiko Kamigaki Mari Okiyama Atsushi Takada Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1988,25(3):1015-1018
The reactions of the pyrazole-5-diazonium salt 3 with malononitrile and ethyl cyanoacetate gave 4-amino-3-cyano-8-ethoxycarbonylpyrazolo[5,1-c][1,2,4]triazine 7 and 4-amino-3,8-bisethoxycarbonylpyrazolo[5,1-c]-[1,2,4]triazine 8 , whose reactions with p-chloroaniline hydrochloride afforded 4-amino-8-ethoxycarbonyl-3-(p-chlorophenyl)amidinopyrazolo[5,1-c][1,2,4]triazine 9 and 4-amino-8-ethoxycarbonyl-3-(p-chlorophenyl)car-bamoylpyrazolo[5,1-c][1,2,4]triazine 10 , respectively. The reactions of 7 and 8 with o-phenylenediamine di-hydrochloride provided 9-ethoxycarbonyl-13H-spiro[benzimidazole-2′(3′H),6(5H)-pyrazolo[1,5′:3,4][1,2,4]tri-azino[5,6-b][1,5]benzodiazepine] hydrochloride 11a and 9-ethoxycarbonyl-6-oxo-13H-5,6-dihydropyrazolo-[1′,5′:3,4][1,2,4]triazino[5,6-b][1,5]benzodiazepine 12 , respectively. The antifungal activity of the above compounds was described. 相似文献
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Yoshihisa Kurasawa Mari Okiyama Yumiko Kamigaki Megumi Kanoh Atsushi Takada Yoshihisa Okamoto 《Journal of heterocyclic chemistry》1988,25(4):1259-1262
The reactions of the 3-substituted 4-amino-8-ethoxycarbonyl[5,1-c][1,2,4]triazines 1 and 2 with o-amino-phenol hydrochloride gave the pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6-b][1,5]benzoxazepines 5 and 8 . The alkylation of 5 with methyl iodide and isopropyl iodide afforded the 6-alkoxylpyrazolo[1′,5′:3,4][1,2,4]triazino-[5,6-b][1,5]benzoxazepines 6a and 6b , respectively. Refluxing of 5, 6a, 6b and 8 in hydrochloric acid/acetic acid resulted in ring transformation to produce the spiro[benzoxazole-2′(3′H),4(1H)pyrazolo[5,1-c][1,2,4]-triazines] 7a, 7b and 9 . The screening data of the above compounds was described. 相似文献
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Victoria V. Lipson Irina V. Ignatenko Sergey M. Desenko Svetlana V. Shishkina Oleg V. Shishkin Sergey A. Komykhov Natalya V. Logvinenko Valery D. Orlov Herbert Meier 《Journal of heterocyclic chemistry》2003,40(6):1081-1086
The reaction of 5,7‐diphenyl‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine ( 1 ) with α,β‐unsaturated carbonyl compounds 2a‐f led to the formation of the alkylated heterocycles 3a‐f (Figure 1). However, the reaction of 5‐methyl‐7‐phenyl‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine ( 5 ) with 2a‐c yielded under the same conditions the triazolo[5,1‐b]quinazolines 6a‐c (Figure 3). In this case, the alkylation is followed by a cyclocondensation. The structure elucidation of the products is based on ir, ms, 1H and 13C nmr measurements and on an X‐ray diffraction study. 相似文献
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Yoshihisa Kurasawa Yoshihisa Okamoto Atsushi Takada 《Journal of heterocyclic chemistry》1987,24(6):1799-1801
Novel 3-substituted 4-amino-8-ethoxycarbonylpyrazolo[5,1-c][1,2,4]triazines 7,8 were synthesized by the reactions of malononitrile and ethyl cyanoacetate with the pyrazole-5-diazonium salt 3 . Moreover, compounds 7,8 were converted into the pyrazolo[1′,5′:3,4][1,2,4]triazino[5,6-b][1,5]benzodiazepines 9, 10 . 相似文献
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Antonino Lauria Patrizia Diana Paola Barraja Anna Maria Almerico Girolamo Cirrincione Gaetano Dattolo 《Journal of heterocyclic chemistry》2000,37(4):747-750
Derivatives of the new ring system pyrrolo[3,4‐e][1,2,3] triazolo[1,5‐a]pyrimidine 6 were prepared in high yields in one step by reaction of 3‐azidopyrrole 3 and substituted acetonitriles. Compound 6b rearranged, upon heating in dimethyl sulfoxide in the presence of water, to pyrrolo[3,4‐d][1,2,3]triazolo‐[1,5‐a]pyrimidine 7. 相似文献
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Radineh Motamedi Majid M. Heravi Fatemeh F. Bamoharram Anahita Haeri 《Journal of heterocyclic chemistry》2008,45(4):1211-1214
Cyclization of 4‐amino‐6‐methyl‐3‐propargylmercapto‐1,2,4‐triazine‐5‐one 3 and 4‐amino‐3‐propargyl mercapto‐1,2,4‐triazole derivatives 6 were afforded 1,2,4‐triazino[3,4‐b][1,3,4]thiadiazines 4 and 1,2,4‐triazolo[3,4‐b][1,3,4]thiadiazines 7 in presence of heteropolyacids, H14[NaP5W29MoO110] and H6P2W18O60 in high yields. Among used heteropoly acids, the yields were higher with H14‐P5Mo, caused to their high acid strengths. 相似文献
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《Journal of heterocyclic chemistry》2017,54(1):235-241
Several new pyrimido[4,5‐e ][1,2,4]triazolo[3,4‐b ][1,3,4]thiadiazine derivatives ( 5a , 5b , 5c , 5d , 5e , 5f , 5g ) were synthesized through the condensation reaction of 5‐bromo‐4,6‐dichloropyrimidine ( 1 ) and 4‐amino‐5‐methyl‐4H‐1,2,4‐triazole‐3‐thiol ( 2 ). The single crystal X‐ray data of one of the derivatives confirmed the occurrence of the S/N type Smiles rearrangement during the course of the reaction. 相似文献