共查询到20条相似文献,搜索用时 10 毫秒
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Klyba L. V. Nedolya N. A. Sanzheeva E. R. Tarasova O. A. 《Russian Journal of Organic Chemistry》2019,55(4):518-524
Russian Journal of Organic Chemistry - Electron impact (70 eV) and chemical ionization (methane as reactant gas) mass spectra of alkyl 5-amino-3-methyl-4-(1H-pyrrol-1-yl)thiophene-2-carboxylates... 相似文献
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V. N. Marshalkin A. V. Samet V. V. Semenov 《Chemistry of Heterocyclic Compounds》1998,34(12):1409-1411
Reaction of 2-carbomethoxy-ω-nitroacetophenone with arylmethylenemalononitriles gives the previously unknown 2-amino-4-aryl-5-nitro-6-(2-carbomethoxyphenyl)-4H-pyran-3-carbonitriles.
N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. E-mail: muskat@cacr.ioc.ac.ru.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1661–1663, December, 1998. 相似文献
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Klyba L. V. Nedolya N. A. Sanzheeva E. R. Tarasova O. A. 《Russian Journal of Organic Chemistry》2019,55(6):824-830
Russian Journal of Organic Chemistry - Fragmentation of N, N-dialkyl-7-[alkyl and 2-(vinyloxy)ethyl]-2,7-dihydrothiopyrano[2,3-b]pyrrol-6-amines under electron impact (70 eV) and chemical... 相似文献
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Klyba L. V. Nedolya N. A. Sanzheeva E. R. Tarasova O. A. 《Russian Journal of Organic Chemistry》2021,57(12):1901-1912
Russian Journal of Organic Chemistry - The fragmentation of 5-[(cyanomethyl)sulfanyl]- and 5-[(1,3-dioxolan-2-ylmethyl)sulfanyl]-1H-pyrrol-2-amines under electron impact (70 eV) and chemical... 相似文献
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We have reported DBU catalyzed synthesis of 4-unsubstituted 2-amino-4H-chromene-2-carbonitriles in water under reflux. The attractive features of this process are mild reaction conditions, short reaction times, easy isolation of products and good yields. 5H-chromeno[2,3-b]pyridine-3-carbonitriles were obtained by refluxing excess of malononitrile and quaternary ammonium salts in ethanol in the presence of NaOH as catalyst. The mechanisms of these reactions are believed to involve the formation of the o-quinone methide intermediate. 相似文献
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Tarik E. Ali Somaia M. Abdel-Kariem 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):1942-1947
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Nguyen Dinh Thanh Do Son Hai Vu Thi Ngoc Bich Pham Thi Thu Hien Nguyen Thi Ky Duyen Nguyen Thi Mai 《合成通讯》2019,49(1):102-117
A series of 2-amino-7-hydroxy-4H-chromene-3-carbonitriles 4a–l were synthesized through three-component reaction using sodium carbonate as a catalyst. The reaction was carried out in 96% ethanol-water medium (1:20 ratio in volume). Propargyl ether compounds 5a–l of these chromene-3-carbonitriles were successfully synthesized from corresponding hydroxyl chromene derivatives by reaction with propargyl bromide. Two different procedures were applied in this process: the procedure that used potassium carbonate in dried acetone and the procedure that used sodium hydride in dried DMF. The latter gave the ethers 5a–l in higher yields. The single-crystal X-ray structure of propargyl ether 5g has been recorded. 相似文献
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The organocatalyzed enantioselective synthesis of a series of chiral 2-amino-5,6,7,8-tetrahydro-5-oxo-4H-chromene-3-carbonitriles was achieved using bifunctional squaramides as the catalysts. The tandem Michael addition–cyclization reaction of cyclohexane-1,3-diones and benzylidenemalononitriles gave the corresponding products in excellent yields (up to 99%) and moderate to good enantioselectivities (up to 83% ee). This investigation provides an efficient and useful process for the synthesis of chiral 2-amino-4H-chromenes. 相似文献
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Kayukov Ya. S. Grigor’ev A. A. Karpov S. V. Kayukova O. V. Mikhaylov A. A. 《Russian Journal of Organic Chemistry》2020,56(7):1187-1190
Russian Journal of Organic Chemistry - Base-catalyzed reaction of 3-aroyl-6-halopyridine-3,5-dicarbonitriles with alcohols involved successive regioselective pyrrole ring fusion at the pyridine [c]... 相似文献
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在正常毛细管温度(200 ℃)下,利用电喷雾质谱(ESI-MS)研究了NaNO3、KNO3、NaNO2和KNO2形成的新型簇合物离子,采用电喷雾多级串联质谱(ESI-MSn)研究了簇合物离子裂解行为.实验结果表明: NaNO3和KNO3溶液产生的簇合物离子及这些离子的裂解方式相似;NaNO2溶液产生的簇合物离子比NaNO3和KNO3溶液产生的复杂;KNO2溶液产生了含有Na+离子的簇合物离子,通过分析KNO2簇合物离子的裂解行为证明了Na+与NO-2的亲合势大于K+.此外,还研究了离子源金属毛细管温度和溶液浓度对簇合物离子形成的影响. 相似文献
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Shu XU Jia Xi XU 《中国化学快报》2006,17(8):1069-1072
Many four- and six-membered ring rearrangements have been observed under mass spectrometric ionization conditions to date1-7. 1-(Benzyloxycarbonyl)amino-2-alkyl/ cycloalkyl thioacetates are key intermediates for the synthesis of 1-substituted and cyclic t… 相似文献
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he decomposition paths of tetraalkyl pyrophosphates under conditions of electron ionization in the mode of registration of positive ions correspond to the general pattern of fragmentation of phosphoric acids esters elucidated earlier by the authors. Electron ionization mass spectra in the mode of registration of negative ions by resonant electron capture are an effective means for extracting information on the number of carbon atoms in the alkyl radicals of tetraalkyl pyrophosphates and full esters of other phosphoric acids 相似文献
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Pyrrolo[3,4-d]-1,2,4-triazolo[1,5-a]pyrimidinone ( 3d ), pyrido[3,4-d]-1,2,4-triazolo[1,5-a]pyrimidinone ( 3e ) and pyrido[4,3-e]-1,2,4-triazolo[1,5-a]pyrimidinone ( 4e ) derivatives representing three new ring systems were synthesised. Their structure was proved by comparing their uv and cmr spectra with those of the known benzo- and thieno-1,2,4-triazolo[1,5-a]pyrimidinones used as model compounds. 相似文献
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M. G. Voronkov L. V. Klyba V. P. Baryshok G. A. Kuznetsova 《Chemistry of Heterocyclic Compounds》2002,38(1):110-115
The fragmentation pathways of singly- and doubly-charged ions in the mass spectra of Si-, N-, and C-substituted 1,3-dioxa-6-aza-2-silacyclooctanes upon electron impact have been studied. The directions for the fragmentation of the singly- and doubly-charged molecular ions differ markedly. All the doubly-charged fragmentation ions are formed by the loss of neutral molecules from M++ and contain nitrogen and silicon atoms. 相似文献
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《印度化学会志》2021,98(11):100202
A simple and facile two-step synthetic route has been developed for the preparation of 2-amino-4H-chromenes via chalcone intermediate under an ambient condition, along with the crystallographic analysis of the racemic mixture so obtained. The crystal orientation can be very useful for generic drug development in future. The described non-hazardous optimized methodology also provides an alternative simple route to prepare functionalized 2-amino-4H-chromenes of biological interest. 相似文献