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1.
Keitaro Senga Joze Kobe Roland K. Robins Darrell E. O'Brien 《Journal of heterocyclic chemistry》1975,12(5):893-898
The synthesis of a new series of alkylxanthine analogs containing a bridgehead nitrogen atom is reported. 1,3-Dialkylpyrazolo[1,5-a]-1,3,5-triazine-2,4-diones, were prepared by the treatment of 3-methylpyrazolo[1,5-a]-1,3,5-triazine-2,4-dione (3) with the corresponding alkyl iodide. Similarly, the reaction of 3-methyl-7-phenylpyrazolo[1,5-a]-1,3,5-dialkyl-7-phenylpyrazolo[1,5-a]-1,3,5-triazine-2,4-diones. The starting materials, 3 and 17 , were prepared via the reaction of an appropriate 3-aminopyrazole with ethoxycarbonyl isothiocyanate. Several 8-bromo derivatives were prepared by direct bromination of the 1,3-dialkylpyrazolo[1,5-a]-1,3,5-triazine-2,4-diones. 相似文献
2.
Suitably protected carbohydrates were joined together using 1,5-disubstituted 1,2,3-triazolylmethylene (1,5-DTM) linkers. The DTM linker was built by the 1,3-dipolar cycloaddition reactions of a series of sugar azides with vinyl sulfonylmethylene-modified furanose or pyranose under metal free conditions. Three different biodegradable hydroxylammonium based ionic liquids were studied in water as the reaction media. The N,N-dimethyl ethanolammonium formate-water mixture was found to be the best reaction medium because the reaction time was shortened considerably to generate a dozen new 1,5-DTM-linked disaccharides. 相似文献
3.
According to the Ullman reaction mechanism, the synthesis of 1,5-di(o-anisidino)anthraquinone was achieved by the multiphase reaction of 1,5-dichloroanthraquinone in xylene and o-anisidine in the presence of copper metal powder and potassium acetate. The effects of various factors on the reaction, such
as the dosages of xylene and catalyst, molar ratios of raw materials, and reaction times were investigated. When the molar
ratio of 1,5-dichloroanthraquinone to o-anisidine and potassium acetate is 1:10:2.5 and the catalyst dosage based on 1,5-dichloroanthraquinone is 5.3%, the conversion
of 1,5-dichloroanthraquinone is 97.8% and the yield of 1,5-di(o-anisidino)anthraquinone is 80.6% after reflux for 10 h. Under these conditions, the recovery of the solvent is 86.0%. The
target compound was identified by MS, 1H NMR, IR and DSC.
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Translated from Journal of Dalian University of Technology, 2007, 47(2): 170–174 [译自: 大连理工大学学报] 相似文献
4.
电化学还原合成1,5-二氨基萘 总被引:3,自引:0,他引:3
研究了以1,5-二硝基萘为原料电化学还原合成1,5-二氨基萘的反应. 室温下, 运用循环伏安法研究了1,5-二硝基萘的循环伏安行为, 1,5-二硝基萘的还原是一受扩散控制的不可逆反应; 循环伏安图上两个连续的还原峰对应于两个硝基的还原; 求出了反应的传递系数α1在0.275~0.335之间, α2在0.360~0.437之间. 探讨了电解电位(E)、底物浓度(c1)、电解电量(Q)、硫酸浓度(c2)以及溶剂(DMF)与水的体积比(Y)对产物产率的影响, 在最优条件下1,5-二氨基萘的产率最高可达77%. 相似文献
5.
Mehwish Iftikhar 《Journal of carbohydrate chemistry》2017,36(8-9):295-306
A straightforward synthesis of N-alkylated 1-deoxynojirimycin derivatives modified at the 6-O-position has been described. The key intermediate in the synthesis of target compounds was 2,3,4-tri-O-benzyl-1,5-dideoxy-1,5-imino-D-glucitol, which was prepared from 2,3,4,6-tetra-O-benzyl-1,5-dideoxy-1,5-imino-D-glucitol. Optimal conditions have been established for the synthesis of the key intermediate by varying reaction parameters. Reductive amination and subsequent alkylation of the 6-O-position followed by hydrogenolysis were the main reaction steps, which gave target compounds 6-O-ethyl-N-octyl-1,5-dideoxy-1,5-imino-D-glucitol and 6-O-butyl-N-octyl-1,5-dideoxy-1,5-imino-D-glucitol. This synthetic route is flexible and can be useful for the synthesis of other lipophilic iminosugar derivatives. 相似文献
6.
L. S. Kosolapova A. R. Kurbangalieva M. F. Valiev O. A. Lodochnikova E. A. Berdnikov G. A. Chmutova 《Russian Chemical Bulletin》2013,62(2):456-463
Reactions of 3-chloro-5-methoxy-4-[(4-methylphenyl)sulfanyl]-2(5H)-furanone with different nitrogen-containing binucleophilic agents were studied. The reaction with hydrazine monohydrate resulted in the formation of 1,5-dihydro-2H-pyrrol-2-one and pyridazin-3(2H)-one derivatives, whereas the reaction with phenylhydrazine led exclusively to 1-phenylamino-1,5-dihydro-2H-pyrrol-2-one. The reaction with ethylenediamine resulted in the isolation of 1,2-bis[2-oxo-1,5-dihydro-2H-pyrrol-1-yl]ethane: the enantiomeric dl-pair and two poly-morphic modifications of meso-form, which were characterized by X-ray crystallography. 相似文献
7.
Fawi M. Abd El Latif Eman A. El‐Rady Mohamed A. Khalil M. A. El‐Maghraby 《Journal of heterocyclic chemistry》2002,39(2):299-302
Novel polysubstituted ‐1,5‐benzothiazepine, ‐1,5‐benzoxazepine, and ‐1,5‐benzodiazepine were prepared in good yields by the reaction of hydrazono derivatives with o‐thioaminophenol, o‐aminophenol and o‐phenylenediamine via a one‐pot reaction. 相似文献
8.
Vivek K. Srivastava Madhuchhanda Maiti Raksh V. Jasra 《European Polymer Journal》2011,47(12):2342-2350
The cyclodimerization of 1,3-butadiene was performed to synthesize 1,5-cyclooctadiene by using nickel-phosphite based catalyst system. The optimization of cyclodimerization reaction was done to achieve up to 80% selectivity towards 1,5-cyclooctadiene. 1,5-Cyclooctadiene, thus synthesized, was subsequently employed as a chain transfer agent (CTA) for controlling the molecular weight (M.W.) of cis-polybutadiene rubber (BR) in cobalt-complex catalyzed 1,3-butadiene polymerization reaction. The M.W. of BR was reduced from 6.7 to 1.88 × 105 g/mol by escalating the concentration of 1,5-cyclooctadiene from 0% to 0.5% with respect to 1,3-butadiene (monomer) concentration. Similar reducing trend was observed for the Mooney viscosity and gel content of BR with increasing 1,5-cyclooctadiene concentration. The efficacy of 1,5-cyclooctadiene as a CTA for 1,3-butadiene polymerization reaction was further explored by conducting polymerization reaction in various solvents and at higher monomer conversion (∼70%). The effect of 4-vinyl cyclohexene, which was a dominant byproduct during cyclodimerization of 1,3-butadiene, was also investigated. The presence of 4-vinyl cyclohexene has shown adverse effect in the polymerization reaction and was not functioning as a chain transfer agent. Finally, a feasibility of replacement of commercially used gaseous CTA, 1,2-butadiene, by in-house synthesized liquid CTA, 1,5-cyclooctadiene, was also investigated. 相似文献
9.
Design and Synthesis of Novel 2‐(1,2,4‐triazol‐1‐yl)‐quinoline‐Based Tricyclic 1,5‐benzothiazepine Derivatives 下载免费PDF全文
A series of new tricyclic 1,5‐benzothiazepine derivatives containing 2‐(1,2,4‐triazol‐1‐yl)quinoline were synthesized by the reaction of 1,5‐benzothiazepine with benzohydroximinoyl chlorides via 1,3‐dipolar cycloaddition reaction. The structures of the target compounds were confirmed by IR, 1H NMR, MS, elemental, and X‐ray crystallographic analysis. 相似文献
10.
Pyrazolo[1,5-a]pyridines and 6-iodopyrazolo[1,5-a]pyridines were synthesized by gold-catalyzed and iodine-mediated cyclization of enynylpyrazoles in good to excellent yields, respectively. The iodinated adducts were further converted to 6-arylpyrazolo[1,5-a]pyridines via Suzuki-Miyaura coupling reaction and 6-cyanopyrazolo[1,5-a]pyridine by Ullmann condensation reaction. One of the cyclization adducts, 2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine, was converted to a p38 kinase inhibitor, 2-(4-fluorophenyl)-3-(4-pyridinyl)pyrazolo[1,5-a]pyridine, in two steps. 相似文献
11.
Syroeshkina Yu. S. Petukhova V. Yu. Kachala V. V. Nelyubina Yu. V. Makhova N. N. 《Russian Chemical Bulletin》2010,59(7):1433-1441
A reaction of aryl ketenes with 1-arylmethylidenepyrazolidin-1-azomethine imines, generated by the diaziridine ring opening
in 6-aryl-1,5-diazabicyclo[3.1.0]hexanes catalyzed with Et2O·BF3, leads to 1,2-bis(phenylacetyl)pyrazolidine, 2-arylacetyl-1-arylidenepyrazolidin-1-ium
chlorides, or a representative of 1,5-diazabicyclo[3.3.0]octan-2-ones, viz., 4-(4-eth-oxyphenyl)-3,3-diphenyl-1,5-diazabicyclo[3.3.0]octan-2-one, depending on the reaction conditions and the structure
of the starting compounds. A mechanism suggested earlier for the transformation of 1,5-diazabicyclo[3.1.0]hexanes in the reaction
with ketenes was confirmed. 相似文献
12.
Felicia Phei Lin Lim Giuseppe Luna Khai Ching Tan Edward R.T. Tiekink Anton V. Dolzhenko 《Tetrahedron》2019,75(15):2322-2329
3-Amino-substituted 5-aminopyrazoles were found to be suitable substrates for the synthesis of new 4-aminopyrazolo[1,5-a][1,3,5]triazines (5-aza-9-deaza-adenines) when used in the one-pot, three-component reaction with cyanamide and triethyl orthoformate under microwave irradiation. The reaction proceeded selectively and its scope was demonstrated by the preparation of a library of 4-aminopyrazolo[1,5-a][1,3,5]triazines. Some structural aspects of the prepared compounds were investigated using dynamic NMR spectroscopy and X-ray crystallography. The operational simplicity, short reaction time, and good reproducibility are attractive features of the developed robust and practical approach for the synthesis of 7-amino-substituted 4-aminopyrazolo[1,5-a][1,3,5]triazines. 相似文献
13.
《Tetrahedron: Asymmetry》2003,14(1):79-85
Silylation reactions of glucono-1,5-lactone can give the persilylated glucono-1,5-lactone or the persilylated 1,4-lactone depending on the reaction conditions employed. The structure of 2,3,5,6-tetra-O-(tert-butyldimethylsilyl)-d-glucono-1,4-lactone, obtained in 84% yield from the reaction of glucono-1,5-lactone with TBSOTf and lutidine in dichloromethane, has been confirmed by X-ray crystallography. Formation of the glucono-1,5-lactone and manno-1,5-lactone derivatives and other possible products has also been ruled out by synthesis of possible exo-glycal derivatives of these lactones using the Ramberg–Bäcklund rearrangement of the corresponding sulfones. 相似文献
14.
Naoki KakusawaYoshinori Tobiyasu Shuji YasuikeKentaro Yamaguchi Hiroko SekiJyoji Kurita 《Tetrahedron letters》2003,44(47):8589-8592
The reaction of 12-arylethynyl-6-methyl-5,6,7,12-tetrahydrodibenzo[c,f][1,5]-azastibocines with organic halides such as acyl halides and aryl halides in the presence of PdCl2(PPh3)2 as a catalyst led to the formation of cross-coupling products, alkynyl ketones and diaryl acetylenes, in good yields. The reactivity of the ethynyl group on the 1,5-azastibocines was far superior to that on diphenyl(phenylethynyl)stibane, which brought about marked improvement in the reaction conditions (lower temperature and shorter reaction time) and in the yields of the cross-coupling products. Single-crystal X-ray analysis of the ethynyl-1,5-azastibocine showed the presence of intramolecular Sb?N interaction which should be responsible for the remarkable reactivity enhancement of the 1,5-azastibocines for this type of reaction. 相似文献
15.
Rate constants for 1,5- and 1,6-hydrogen atom transfer reactions in models of polyunsaturated fatty acid radicals were measured via laser flash photolysis methods. Photolyses of PTOC (pyridine-2-thioneoxycarbonyl) ester derivatives of carboxylic acids gave primary alkyl radicals that reacted by 1,5-hydrogen transfer from mono-, di-, and tri-aryl-substituted positions or 1,6-hydrogen transfer from di- and tri-aryl-substituted positions to give UV-detectable products. Rate constants for reactions in acetonitrile at room temperature ranged from 1 x 10(4) to 4 x 10(6) s(-1). The activation energies for a matched pair of 1,5- and 1,6-hydrogen atom transfers giving tri-aryl-substituted radicals were approximately equal, as were the primary kinetic isotope effects, but the 1,5-hydrogen atom transfer reaction was 1 order of magnitude faster at room temperature than the 1,6-hydrogen atom transfer reaction due to a less favorable entropy of activation for the 1,6-transfer reaction. Solvent effects on the rate constants for the 1,5-hydrogen atom transfer reaction of the 2-[2-(diphenylmethyl)phenyl]ethyl radical at ambient temperature were as large as a factor of 2 with the reaction increasing in rate in lower polarity solvents. Hybrid density functional theory computations for the 1,5- and 1,6-hydrogen atom transfers of the tri-aryl-substituted donors were in qualitative agreement with the experimental results. 相似文献
16.
M. I. Enmakova N. K. Karnaukhova I. A. Shikhova N. I. Latosh 《Chemistry of Heterocyclic Compounds》1977,13(12):1344-1346
Several 1,5-diphenyl-3-tetrazolylformazans were synthesized by reaction of 1,5-diaryl-3-cyanoformazans with sodium azide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1679–1681, December, 1977. 相似文献
17.
James J. Wade 《Journal of heterocyclic chemistry》1986,23(4):981-987
Two complementary procedures, each starting from 6-aminomethyluracil ( 2 ), have been used to prepare imidazo[1,5-c]pyrimidines with a variety of substituents at positions 3, 5, 6, and 7. The starting material, 2 , can be readily prepared from commercially available 6-chloromethyluracil by reaction with anhydrous ammonia. In the first procedure, 2 is acylated and then cyclodehydrated by reaction with phosphorus oxychloride to give a separable mixture of a 3-substituted 5,7-dichloroimidazo[1,5-c]pyrimidine and a 3-substituted 7-chloroimidazo[1,5-c]pyrimidin-5(6H)-one. The relative product distribution is subject to some control by the choice of the acyl substituent on the starting uracil. The resulting dichloro compounds were derivatized by reaction at the 5-position with various nucleophiles, although the 7-chloro substituent is unreactive. An alternative synthetic method proceeds from 2 in six efficient steps (protection as the phthalimide, chlorination, nucleophilic substitution, deprotection, acylation, and cyclodehydration) to 3-substituted-5,7-bis(methylthio)imidazo[1,5-c]pyrimidines. These compounds may also be derivatized by nucleophilic substitution at the 5-position. 相似文献
18.
Fabrizio Bruni Silvia Selleri Annarella Costanzo Gabriella Guerrini Maria Lucia Casilli Laura Giusti 《Journal of heterocyclic chemistry》1995,32(1):291-298
A series of pyrazolo[1,5-a]pyrido[3,4-e]pyrimidin-6-ones was obtained by reaction of ammonium acetate with ethyl 7-dimethylaminovinylpyrazolo[1,5-a]pyrimidine-6-carboxylates and these had been prepared from ethyl 7-methylpyrazolo[1,5-a]pyrimidine-6-carboxylates by reaction with dimethylformamide dimethylacetal. Under these conditions the compounds bearing a 2-hydroxy group were also O-alkylated. During the preparation of the ethyl 2-hydroxy-7-methyl-3-phenylpyrazolo[1,5-a]pyrimidine-6-carboxylate the corresponding 5-methyl isomer was isolated and identified. 相似文献
19.
Anna Borioni Maria Rosaria Del Giudice Carlo Mustazza Franco Gatta 《Journal of heterocyclic chemistry》2000,37(4):799-810
This paper describes the synthesis of some bicyclic 2‐(3‐dimethylcarbamoyloxyphenyl) substituted azaderivatives, obtained from 1,4‐ and 1,5‐diketones, which were cyclized with ammonium acetate, methylamine and by reductive amination. Corresponding 3‐substituted derivatives were instead prepared by reaction of 1,5‐ketoesters with formamide. The carbamates were tested as in vitro acetylcholinesterase inhibitors. 相似文献