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1.
An efficient, convenient synthesis of 1,4-benzoxazines, 1,4-benzothiazines, spiro-1,4-benzoxazines, and spiro-1,4-benzothiazines derivatives was accomplished in good yields via the novel intramolecular cyclization mediated by mild base K2CO3 in ethanol solvent. A variety of substrates can participate in the process with good yields, making this methodology have broad applicability. All the structures of synthesized compound have been confirmed by spectral analysis. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications ® to view the free supplemental file. 相似文献
2.
A. K. Mitra V. B. Gawandi K. George H. Mohan T. Mukherjee 《Research on Chemical Intermediates》2008,34(1):85-92
5,8-dihydroxy-1,4-dihydro-1,4-methanonaphthalene (DDMN), a substituted phenol, is synthesized by reduction of a cyclic dione,
1,4,4a,8a-tetrahydro-endo-1,4-methano-naphtha-5,8-dione (THMND). Pulse radiolysis technique has been employed to understand
the nature of transient species formed on reaction of radiolytic species of water radiolysis with DDMN.•OH radicals were observed to react with DDMN with a bimolecular rate constant of 1.5×1010 dm3 mol−1 s−1. Inhibition of radiation induced lipid-peroxidation by DDMN was studied in rat liver microsomes by assessing the formation
of thiobarbituric acid reactive substances (TBARS). It was found to be strongly inhibitory. The results suggest that DDMN
has very good antioxidant activity and may possibly emerge as a good radio-protector. 相似文献
3.
Simons electrochemical fluorination (ECF) of 1,4-dimethyl-1,4-homopiperazine, methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine was studied. For comparison, ECF of three piperazines with a N-(methoxycarbonylmethyl) group(s) was also studied. ECF of 1,4-dimethyl-1,4-homopiperazine gave a low yield of corresponding perfluoro(1,4-dimethyl-1,4-homopiperazine) together with perfluoro(2,6-diaza-2,6-dimethylheptane) as the major product. Corresponding perfluoro(homopiperazines) with mono- and/or di-(fluorocarbonyldifluoromethyl) groups [CF2C(O)F] at the 1- and/or 4-position were formed in low yields from methyl 4-ethylhomopiperazin-1-ylacetate and 1,4-bis(methoxycarbonylmethyl)-1,4-homopiperazine, respectively. These new seven-membered perfluoro(1,4-dialkyl-1,4-homopiperazines) were accompanied by the formation of mono- and/or di-basic linear perfluoroacid fluorides resulting from the CC bond scission at the 2- and 3-positions of the ring. From mono- and/or di-N-(methoxycarbonylmethyl)-substituted piperazines, corresponding perfluoropeperazines having the acid fluoride group(s) were formed in low yields. 相似文献
4.
O. V. Shishkin 《Monatshefte für Chemie / Chemical Monthly》1996,127(8-9):883-886
Summary The molecular geometry of 4-oxo derivatives of 1,4-dihydropyridine, 1,4-dihydropyrimidine, 1,4-dihydropyridazine, and 1,4-dihydro-1,3,5-triazine has been calculated by the semi-empirical quantum-chemical AM1 method. It could be shown that the dihydrocycle in these compounds is not conformationally rigid. Changing the angle between the endocyclic double bond planes ±15° causes less than 1 kcal/mol increase of energy.
Konformative Flexibilität von 1,4-Dihydroazin-carbonyl-Derivaten (Kurze Mitt.)
Zusammenfassung Die molekulare Geometrie von 4-Oxo-Derivaten von 1,4-Dihydropyridin, 1,4-Dihydropyrimidin, 1,4-Dihydropyridazin und 1,4-Dihydro-1,3,5-triazin wurde mittels der semiempirischen quantenchemischen AM1-Methode berechnet. Es konnte gezeigt werden, daß der zweifach hydrierte Ring in diesen Verbindungen nicht starr ist. Eine Änderung des Winkels zwischen den Ebenen der endocyclischen Doppelbindungen um ±15° bewirkt eine Energieerhöhung von weniger als 1 kcal/mol.相似文献
5.
Zeliha Gokmen Mehmet Erdi Onan Nahide Gulsah Deniz Didem Karakas Engin Ulukaya 《合成通讯》2013,43(21):3008-3016
1,4-Naphthoquinones (1,4-NQ) have been reported to possess a variety of pharma-cological properties including antibacterial, antifungal, antiviral, anti-inflammatory, anti-artherosclerotic, and anticancer effects. In this study, new N- and S,S-substituted-1,4-NQ derivatives were synthesized in excellent yields and were completely characterized by spectroscopic analysis IR, NMR (1H and 13C), MS and microanalysis. The cytotoxic activities of 1,4-NQ derivatives were examined against to A-549, DU145, HCT-116 and MDA-MB-231 cancer cells. Among these compounds, 2-[4-(2-furoyl)piperazine-1-yl]-3-chloro-1,4-NQ 5 and 2,3-bis(cyclobuthylsulfanyl)-1,4-NQ 17 were identified as the most potent anticancer agents with cytotoxic activity against three cell lines (breast (MDA-MB-231), prostate (DU145), colorectal (HCT-116). 相似文献
6.
The 1,4-benzodioxin-2-carboxylic esters or carboxamides react with nucleophilic amines to give access to 3-hydroxy-2,3-dihydro-1,4-benzodioxin-2-carboxamides and 3-aminomethyn-1,4-benzodioxin-2(3H)-one precursors of potential therapeutical compounds. The basic environment (K2CO3 or amine) facilitates the process. 相似文献
7.
Nicolas Wlodarczyk 《Tetrahedron letters》2007,48(14):2583-2586
A new efficient access to 1,4-diazepane derivatives is described via a microwave assisted synthesis of 7-substituted-1,4-diazepin-5-ones, which proceeds rapidly in good yields. Catalytic reduction gave 1,4-diazepan-5-ones and 1,4-diazepanes whereas a ring opening was observed by hydride reduction when a phenyl group occupies the N-benzylic position. 相似文献
8.
A. K. Mitra V. B. Gawandi K. George H. Mohan T. Mukherjee 《Research on Chemical Intermediates》2009,35(1):13-20
5,8-dihydroxy-1,4-dihydro-1,4-methanonaphthalene (DDMN), a substituted phenol, is synthesized by the reduction of a cyclic
dione, 1,4,4a,8a-tetrahydro-endo-1,4-methano-naphtha-5,8-dione (THMND). The pulse radiolysis technique has been employed to
understand the nature of transient species formed by the reaction of radiolytic species of water radiolysis with DDMN. •OH radicals were observed to react with DDMN with a bimolecular rate constant of 1.5 × 1010 dm3 mol−1 s−1. The inhibition of radiation-induced lipid-peroxidation by DDMN was studied in rat liver microsomes by assessing the formation
of thiobarbituric acid reactive substances (TBARS). It was found to be strongly inhibitory. The results suggest that DDMN
has very good antioxidant activity and may possibly emerge as a good radio-protector.
Dr. Hari Mohan: since deceased. 相似文献
9.
An Ir-catalyzed asymmetric hydrogenation of 2-substituted 1,4-benzodioxines was developed for the preparation of chiral 1,4-benzodioxanes, which are present in numerous biologically active compounds and natural products. Our tropos biphenyl phosphine-oxazoline ligand is essential for obtaining good ee. A broad range of substrates were tolerable to the reaction conditions and gave the corresponding hydrogenation products in excellent yields and with moderate to good enantioselectivities using the Ir-complex of our tropos phosphine-oxazoline ligand. 相似文献
10.
N. V. Ivashkina E. A. Yakovleva I. D. Ivanchikova A. A. Moroz M. S. Shvartsberg 《Russian Chemical Bulletin》2005,54(6):1509-1513
Iodination of 5-amino- and 6-amino-1,4-naphthoquinones with I2 and HIO3 in aqueous dioxane occurs only at the benzoid ring. Depending on the reaction conditions, either aminoiodo- or aminodiiodonaphthoquinones
are produced. Diazotization of these compounds followed by reduction or replacement of the diazo group with iodine affords
mono- or polyiodo derivatives of 1,4-naphthoquinone.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1465–1469, June, 2005. 相似文献
11.
P. V. Pasternak V. I. Dyachenko Z. A. Starikova A. S. Peregudov M. Yu. Antipin N. D. Chkanikov 《Russian Chemical Bulletin》2006,55(7):1307-1308
Heating of 2-amino-1-aryl-1,4-dihydropyridines in acidic aqueous media gives 2-arylamino-1,4-dihydropyridines. The reaction
formally involves the migration of the aryl substituent from the endo-to exocyclic N atom.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1259–1260, July, 2006. 相似文献
12.
Water-controlled and phosphine-mediated selective synthesis of saturated 1,4-diketones and tetrasubstituted furans has been developed directly from 1,4-enediones. Saturated 1,4-diketones were selectively obtained in acetone with water as an additive, whereas tetrasubstituted furans were selectively obtained in anhydrous 1,2-dichloroethane. A large variety of functional groups are tolerated under these reaction conditions, including electron-rich, electron-poor, halogen, and heteroaryl substituents. This method also has significant advantages in easily available substrates, mild reaction conditions, and high reaction efficiency. 相似文献
13.
14.
Ferdinand MelkonyanArtiom Topolyan Alexander Karchava Marina Yurovskaya 《Tetrahedron》2011,67(36):6826-6832
Starting from ortho-bromosubstituted phenoxyacetates or (phenythio)acetates and primary amines, various N-substituted 4H-1,4-benzoxazine- and 4H-1,4-benzothiazine-2-carboxylates were synthesized in moderate to high yields by using a Cu(I)-catalyzed Ullmann-type cyclization as a key step. The method is simple to operate, tolerates many functional groups and does not require any additives. 相似文献
15.
Garreth L. Morgans 《Tetrahedron》2009,65(51):10650-6832
A small library of 1,4-benzodioxins and 4H-1,4-benzoxazines was synthesized from the corresponding bis-allyloxy precursors by way of an initial isomerization to the bis-vinyloxy compounds, followed by a ring-closing metathesis using the second generation Grubbs' catalyst (G2). A related strategy, starting from benzene-1,2-dithiol and 2-mercaptophenol, afforded benzodithiin and 1,4-benzoxathiin, respectively. 相似文献
16.
XU Jing-bo ** JING Ti-song LIANG Lin SHENG Lian-xi . Department of Environmental Science Northeast Normal University Changchun P. R. China . College of Environment Resource Jilin University Changchun P. R. China 《高等学校化学研究》2005,21(2):154-157
Introduction Mostnitroaromaticsareprimaryenvironment pollutants.Theseindustrialchemicalshaveahigh exposuretotheaquaticecosystems.1,4-Dini- trobenzene(1,4-DNB)isoneofthemandpreferen- tiallystipulatedbyOECDandEPAofUSA.Sever- alpapershavereportedthetoxicityof1,4-DNBto theaquaticspecies.However,thereisnotasetof systematicdataontheecotoxicologicaleffectofthe chemicalonOryziaslatipes[1_5],whichhavebeen adoptedastheinternationalstandardexperiment fish. Inordertogetfurtherinformationaboutthe p… 相似文献
17.
The novel unsymmetrical 3,5-dialkoxycarbonyl-2,6-dimethyl-4-(7′,8′-dimethoxycoumarin-4′-yl)-1,4-dihydropyridines and 5-acetyl-3-alkoxycarbonyl-2,6-dimethyl-4-(7′,8′-dimethoxycoumarin-4′-yl)-1,4-dihydropyridines (coumarinyl-1,4-dihydropyridines) have been synthesized by Knoevenagel condensation of 4-formyl-7,8-dimethoxycoumarin with alkyl acetoacetates in the presence of AlCl3 followed by cyclization of the resulted Knoevenagel product with other alkyl acetoacetate or acetyl acetone and ammonium acetate. The structure of the intermediate Knoevenagel product and the cyclized unsymmetrical coumarinyl-1,4-dihydropyridines has been established on the basis of their spectral data analysis and single-crystal X-ray diffraction analysis. The observed conformation of the coumarinyl-1,4-dihydropyridines holds the key to promising calcium antagonistic activity of the synthesized coumarinyl-1,4-dihydropyridines. 相似文献
18.
An efficient and convenient method for the synthesis of 1,4-dihydropyridines from β-dicarbonyl compounds, aldehydes, and ammonium acetate and the synthesis of fused 1,4-dihydropyridines from dimedone in the presence of Preyssler heteropolyacid catalyst are reported under reflux conditions with good to excellent yields. Preyssler heteropolyacid catalyst is easily prepared, stable (up to 300 °C), reusable, efficient, green and inexpensive. 相似文献
19.
E. K. Starostin A. A. Mazurchik A. V. Ignatenko G. I. Nikishin 《Russian Chemical Bulletin》1993,42(7):1174-1178
The decomposition of 1,4-dihydroxy-1,4-dihydroperoxycyclohexane under the action of FeSO4 and the decomposition of 1,4-cyclohexanedione monoethyleneketal hydroperoxide under the action of FeII salts in the presence of various ligands or under the action of CuII sulfate have been studied. A preparative method for the synthesis of derivatives of diketodicarboxylic or -functionally substituted ketocarboxylic acids from 1,4-cyclohexanedione monoethyleneketal has been developed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1231–1235, July, 1993. 相似文献
20.
I. Goba B. Turovska J. Stradins I. Turovskis E. Liepinsh S. Belyakov 《Chemistry of Heterocyclic Compounds》2007,43(2):175-186
It has been shown that chemical oxidation of the methyl ester of 3,4,5-trimethoxycarbonyl-1,2,6-trimethyl-1,4-dihydropyridine
to the pyridinium salt, requiring forcing experimental conditions, may be replaced by electrochemical oxidation. On electrochemical
reduction of 3,4,5-trimethoxycarbonyl-1,2,6-trimethylpyridinium perchlorate in the presence of alkylating agents 1,2,3,4,4,5,6-substituted
1,4-dihydropyridines are obtained.
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Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 226–237, February, 2007. 相似文献