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1.
Sergey M. Desenko Sergey A. Komykhov Valery D. Orlov Herbert Meier 《Journal of heterocyclic chemistry》1998,35(4):989-990
The cyclocondensation of 6-acetyl-4,7-dihydro-5-methyl-7-phenyl[1,2,4]triazolo[1,5-a]pyrimidine (3) with hydroxylamine or hydrazine leads to 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenylisoxazolo-[5,4-d][1,2,4]triazolo[1,5-a]pyrimidine ( 4a ) and 3a,4,9,9a-tetrahydro-3,9a-dimethyl-4-phenyl-1H-pyrazolo[3,4-d][1,2,4]triazolo[1,5-a]pyrimidine ( 4b ), respectively. In the presence of methanolic hydrogen chloride, 4b undergoes a cleavage of the pyrimidine ring to yield (5-amino-1,2,4-triazol-1-yl)(3,5-dimethylpyrazol-4-yl)phenylmethane ( 5 ). The structure determination of the compounds obtained is based on 1H and 13C nmr spectra including NOE measurements. 相似文献
2.
Six novel isomeric ring systems, namely the thiopyrano[4,3-d]-1,2,4-triazolo[1,5-a]pyrimidine, the thiopyrano[3,4-e]-1,2,4-triazolo[1,5-a]pyrimidine, the thiopyrano[3,4-d]-1,2,4-triazolo[1,5-a]pyrimidine, the thiopyrano[4,3-e]-1,2,4-triazolo[1,5-a]pyrimidine, the thiopyrano[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidine and the thiopyrano[2,3-e]-1,2,4-triazolo[1,5-a]pyrimidine were synthesised. Spectroscopical evidence was given for the structure of compounds obtained. 相似文献
3.
Mohammed Loubidi Anaïs Moutardier Joana F. Campos Sabine Berteina-Raboin 《Tetrahedron letters》2018,59(11):1050-1054
A rapid and efficient method is reported for the synthesis of the [1,2,4]triazolo[1,5-a]pyrimidine motif. Palladium catalyzed Suzuki and Sonogashira cross coupling reactions on 7-chloro-5-methyl-[1,2,4]triazolo[1,5-a]pyrimidine were performed. The direct sp3 arylation of compounds resulting from the Suzuki reaction was then carried out. 相似文献
4.
Dihydro derivatives of pyrazolo[3,4-b]pyridine-, pyrazolo[1,5-a]pyrimidine-, and [1,2,4]triazolo-[1,5-a]pyrimidinecarboxylates have been prepared by cyclocondensation of β-aroylacrylates with 5-aminopyrazoles and 3-amino-1,2,4-triazole.
Heating dihydro[1,2,4]triazolo[1,5-a]pyrimidine-7-carboxylates with hydrazine hydrate led to recyclization of the pyrimidine
ring to form 6-arylpyridazin-3(2H)-ones. 相似文献
5.
Three novel ring systems, namely the thieno[3,4-d]-1,2,4-triazolo[1,5-a]pyrimidine, the thieno[3,4-e]-1,2,4-triazolo[1,5-a]pyrimidine and the thieno[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidine were synthesised. The structure of compounds obtained was proved with the help of their uv and cmr spectra using model compounds prepared for this purpose. 相似文献
6.
《Journal of carbohydrate chemistry》2013,32(4):305-312
Reactions of 2-formylgalactal 1, presented as an unsaturated sugar derivative with push-pull functionalization, with guanidinium and amidinium salts, respectively, were carried out under basic conditions to furnish the substituted 5-(1,2,4-tri-O-benzyl-d-lyxo-1,2,3,4-tetrahydroxybutyl)pyrimidines 2–4. Treatment of 1 with 2-aminobenzimidazole and 3-amino-1,2,4-triazole, respectively, afforded 3-(1,2,4-tri-O-benzyl-d-lyxo-1,2,3,4-tetrahydroxybutyl)benzo[4,5]imidazo[1,2-a]pyrimidine (5) and 6-(1,2,4-tri-O-benzyl-d-lyxo-1,2,3,4-tetrahydroxybutyl)-[1,2,4]triazolo[1,5-a]pyrimidine (6). 相似文献
7.
G. G. Danagulyan G. A. Panosyan A. P. Boyakhchyan 《Chemistry of Heterocyclic Compounds》2002,38(5):581-585
With the object of studying the factors influencing the course of enamine rearrangements, we have carried out the N-alkylation of alkyl- and aryl-substituted pyrazolo[1,5-a]pyrimidines. Using the NOEDIF NMR spectroscopic method for the cases of 5,7-dimethyl-2-phenyl- and 2,5,7-triphenylpyrazolo[1,5-a]pyrimidines it was found that addition of the alkyl group occurs at the N(4) atom of the pyrimidine fragment in the pyrazolo[1,5-a]pyrimidine. It was shown that, when reacting with an alcoholic solution of methylamine, the 5,7-dimethyl-2-phenyl- and 2,5,7-triphenylpyrazolo[1,5-a]pyrimidine iodomethylates undergo decomposition to give 5-methylamino-3-phenylpyrazole and 5-(1,3-diphenyl-3-methylamino-2-propenylid-1-ene)amino-3-phenylpyrazole. 相似文献
8.
Victoria V. Lipson Nataliya V. Svetlichnaya Victoria V. Borodina Maria G. Shirobokova Sergey M. Desenko Vladimir I. Musatov Svetlana V. Shishkina Oleg V. Shishkin Roman I. Zubatyuk 《Journal of heterocyclic chemistry》2012,49(5):1019-1025
Formylation of 5‐methyl‐7‐phenyl‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine 1a using Vilsmeier–Haack conditions yields 5‐methyl‐7‐phenyl‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidin‐6‐ylcarbaldehyde 3a . 5,7‐Diaryl‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidines 1b , 1c in this reaction apart from formylation undergo recyclization into 5‐aryl‐1,2,4‐triazolo[1,5‐a]pyrimidin‐6‐ylmethane derivatives 4b , 4c , 5b , 5c , and 6 . The structure of the synthesized compounds was determined on the basis of NMR, IR, and MS spectroscopic data and confirmed by the X‐ray analysis of the 6‐(ethoxy‐phenyl‐methyl)‐5‐phenyl‐[1,2,4]triazolo[1,5‐a]pyrimidine 6 , 5‐phenyl‐6‐(1‐phenyl‐vinyl)‐[1,2,4]triazolo[1,5‐a]pyrimidine 11 , and 7‐phenyl‐6‐(1‐phenyl‐vinyl)‐[1,2,4]triazolo[4,3‐a]pyrimidine 12 . 相似文献
9.
Branko Stanovnik Henry Van De Bovenkamp Jurij Svete Ale Hvala Igor Simoni
Miha Tiler 《Journal of heterocyclic chemistry》1990,27(2):359-361
Methyl 2-benzoylamino-3-dimethylaminopropenoate ( 2 ) was introduced as a new reagent for the preparation of fused pyrimidinones 4 from heterocyclic α-amino compounds in acetic acid. In this manner, derivatives of pyrido[1,2-a]pyrimidine 4a,b,f , pyrimido[1,2-b]pyridazine 4g , pyrimido[1,2-c]pyrimidine 4j , pyrazino[1,2-a]pyrimidine 4k , thiazolo[2,3-b]pyrimidine 41 , pyrazolo[1,5-a]pyrimidine 4m , and 1,2,4-triazolo-[1,5-a]pyrimidine 4n were prepared. 相似文献
10.
In the course of the synthesis of pyrido[4,3-d]-1,2,4-triazolo[1,5-a]pyrimidine derivatives 3c representing a novel ring system an unexpected rearrangement of the intermediate enamines to yield 5 was observed. A mechanism of the formation of 5 was suggested. The isomeric pyrido[4,3-e]-1,2,4-triazolo[1,5-a]pyrimidine derivatives 4c containing also a new ring system were obtained, too. The structure of products obtained was proved with the help of their uv, cmr and X-ray spectra. 相似文献
11.
L. L. Zamigailo O. N. Petrova M. G. Shirobokova V. V. Lipson 《Russian Journal of Organic Chemistry》2013,49(2):288-293
Reactions of 4-oxo benz[1,3-e]oxazinium perchlorates with 1-R1-3-R2-5-aminopyrazoles lead to the formation of derivatives of pyrazolo[3,4-d]pyrimidine and pyrazolo[1,5-a]1,3,5]triazine series, and with 3-amino-1,2,4-triazole, to [1,2,4]triazolo[1,5-a][1,3,5]triazines. 相似文献
12.
以2-溴丙酸甲酯、α,α-二氯甲基甲醚和胍唑为原料, 经缩合以及环化反应制得2-氨基-6-甲基-5-氧代-4,5-二氢-1,2,4-三氮唑并[1,5-a]嘧啶. 为了提高其在有机溶剂中的溶解性, 该化合物再同1-溴丁烷发生亲核取代反应得到了2-氨基-6-甲基-5-氧代-4-正丁基-4,5-二氢-1,2,4-三氮唑并[1,5-a]嘧啶, 然后与芳基醛和叔丁基异氰发生Ugi多组分反应, 合成了一系列具有潜在催吐活性的2-取代氨基-6-甲基-5-氧代-4-正丁基-4,5-二氢-1,2,4-三氮唑并[1,5-a]嘧啶类衍生物, 产品结构经质谱、核磁共振谱及元素分析确认. 相似文献
13.
M. T. Wu M. MacCoss T. J. Ikeler J. Hirshfield B. H. Arison R. L. Tolman 《Journal of heterocyclic chemistry》1990,27(6):1559-1563
Tricyclic analogs of piperazinylthiopyrano[3,2-d]pyrimidine hypoglycemic agents were prepared. The angular tricyclic systems, 8,9-dihydro-7H-thiopyrano[2,3-e][1,2,4]triazolo[4,3-a]pyrimidine and 8,9-dihydro-7H-tetrazolo[1,5-a]thiopyrano[2,3-e]pyrimidine derivatives were synthesized from 2,4-dichloro-7,8-dihydro-6H-thiopyrano[3,2-d]pyrimidine in three step sequences. Derivatives of the linear tricyclic system, 5,6-dihydro-7H-thiopyrano[3,2-d][1,2,4]triazolo[2,3-a]pyrimidine, were prepared by condensation of 3-amino-1,2,4-triazole with ethyl 3-oxo-tetrahydropyran-2-carboxylate. The tricyclic heteroaryl-piperazines lacked significant hypoglycemic activity. 相似文献
14.
The interaction of 3-(R-amino)-3-methylthio-1-phenylpropenones and 1-alkyl-5-benzoyl-3-ethoxy-carbonyl-6-methylthio-1,2-dihydropyridin-2-ones
with N,N- and N,C-1,2- and 1,3-dinucleophiles proceeded regioselectively by [3 + 2] and [3 + 3] cyclocondensation with the
formation of derivatives of pyrazole, benzimidazo[1,2-a]-pyridine, benzimidazo[1,2-a]pyrimidine, imidazo[1,2-a]pyrimidine, [1,2,4]triazolo[4,3-b]pyridazine, and 6,7-dihydro-2H-pyrazolo[3,4-b]pyridine. The regioselectivity of the reactions carried out was analyzed. 相似文献
15.
T. Ramalingam M. S. R. Murty Y. V. D. Nageswar P. B. Sattur 《Journal of heterocyclic chemistry》1990,27(4):981-982
The reaction of 3 -amino-1,2,4-triazolo[4,3-a]quinoline ( II ) with diethyl ethoxymethylenemalonate and ethyl acetoacetate/ethyl trifluoroacetoacetate afforded 10-carboethoxy-9-oxo-9H-pyrimido[1′,2′:1,5][1,2,4]triazolo-[4,3-a]quinoline ( III ) and 11-methyl/trifluoromethyl-9-oxo-9H-pyrimido[1′,2′:1,5][1,2,4]triazolo[4,3-a]quinoline ( IV/V ) respectively. 2-Chloropyridine-3-carboxylic acid chloride reacted with II to yield 5-oxo-5H-pyrido-[3″,2″:5′,6′]pyrimido[1′,2′:1,5][1,2,4]triazolo[4,3-a]quinoline ( VII ), a new ring system. 相似文献
16.
The uv and nmr spectral data of some 6,7,8,9,10,11-hexahydrocyclohepta[d][1,2,4]triazolo[1,5-a]pyrimidin-5-one, 5,6,7,8,9,11-hexahydrocyclohepta[e][1,2,4]triazolo[1,5-a]pyrimidin-10-one, 6,7,8,9,10,11-hexahydrocycloocta[d][1,2,4]triazolo[1,5-a]pyrimidin-5(12H)-one, 5,6,7,8,9,10-hexahydrocycloocta[e][1,2,4]triazolo[1,5-a]-pyrimidin-11(12H)-one, 6,7,8,9,10,11,12,13,14,15-decahydrocyclododeca[d][1,2,4]triazolo[1,5-a]pyrimidin-5(16H)-one and 5,6,7,8,9,10,11,12,13,14-decahydrocyclododeca[e][1,2,4]triazolo[1,5-a]pyrimidin-15(16H)-one as well as their N-benzylated derivatives representing six novel ring systems were compared to prove their structure. The N-benzylation of the highly insoluble cyclic amides to yield the isomeric N-benzyl derivatives 3/1, 3/2 and 3/3 distinguished by INAPT was performed through their readily soluble tetrabutylammonium salts. 相似文献
17.
Whereas 2-amino-3-ethoxycarbonyl-4,5-dihydrofurans Ia-c condense with 5-membered amidine derivatives, via elimination of ethanol to afford the azolopyrimidines IIIa,b, XI, and XIVa,b, the 2-amino-3-cyano-4,5-dihydrofurans Id,e give with the same reagents, under elimination of ammonia, the novel ring systems of furo-azolopyrimidines XVIII and XXa,b. 2-Amino-3-ethoxycarbonyl-5,6-dihydro-4H-thiopyrane (XXI) reacts with 5-amino-1,2,4-triazole (II) to yield the triazolo[1,5-a]pyrimidine XXII, and with 2-aminobenzimidazole to XXIII. The mechanism of these reactions is discussed. XIVb and VIIb are cyclized in a secondary step to give the novel furo[2,3-d]benzimidazo[1,2-a]pyrimidine XXVI, and furo[2,3-d]-1,2,4-triazolo[1,5-a]pyrimidine XXVIII respectively, besides the acetoxy derivatives XVII and XXIX. 相似文献
18.
Shikhaliev Kh. S. Potapov A. Yu. Polukhin E. L. Slivkin A. I. 《Russian Chemical Bulletin》2009,58(9):1996-1999
Pyridoannulation of 5-ethoxycarbonyl-4-methylpyrimidine and 7-methyl-6-ethoxy-carbonyl[1,2,4]triazolo[1,5-a]pyrimidine derivatives has been studied. 相似文献
19.
Mohamed R. Shaaban 《Journal of fluorine chemistry》2008,129(12):1156-1161
4,4,4-Trifluoro-1-(thien-2-yl)butane-1,3-dione (1) reacts with 5-aminopyrazole, 1,2,4-aminotriazole and 2-aminobenzimidazole derivatives, in the presence of triethylorthoformate under pressurized microwave irradiation to afford the corresponding trifluoromethyl derivatives of pyrazolo[1,5-a]pyrimidine, 1,2,4-triazolo[1,5-a]pyrimidine, and pyrimido[1,2-a]benzimidazoles. Also, compound 1 couples readily with azole diazonium salts to give pyrazolo[5,1-c]triazine, benzimidazo[5,1-c]1,2,4-triazine, and triazolo[3,4-c]1,2,4-triazine derivatives incorporating trifluoromethyl group. 相似文献
20.
Thomas Novinson Darrell E. O'Brien Roland K. Robins 《Journal of heterocyclic chemistry》1974,11(6):873-878
A number of imidazo[1,5-a]pyrimidine-8-carboxamides were synthesized by reacting various β-dicarbonyl compounds with 5(4)-aminoimidazole-4(5)carboxamide (AICA, 1 ), the non-ribosylated form of AICAR, a key intermediate in the metabolic pathway of purine biosynthesis. Cyclization of 1 with ethylacetoacetate yielded 2-methylimidazo[1,5-a]pyrimidin-1H-4-one-8-carboxamide ( 2 ). The treatment of 2 with phosphorus oxychloride gave 4-chloro-8-cyano-2-methylimidazo[1,5-a]pyrimidine ( 3 ). Various nucleophiles displaced the 4-chloro substituent of 3 under mild conditions. However, the 4-methylthio group of 8-cyano-2-methyl-4-methylthioimidazo[1,5-a)pyrimidine ( 8a ) was also displaced under very mild conditions. Even more strangely, the 4-diethylamino group of 8-cyano-4-diethylamino-2-methylimidazo[1,5-a]pyrimidine ( 5a ) was displaced by ammonia to give 4-amino-8-cyano-2-methylimidazo[1,5-a]pyrimidine ( 7 ). 相似文献