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1.
Rahman Hosseinzadeh Ali Sharifi Kourosh Tabar-Heydar Farshid Mohsenzadeh 《Monatshefte für Chemie / Chemical Monthly》2002,133(11):1413-1415
Summary. N,N-Dimethylhydrazones of ketones and aldehydes undergo facile cleavage to the corresponding carbonyl compounds upon exposure
to microwaves in water containing a catalytic amount of PdCl2–SnCl2 in high yields.
Corresponding authors. E-mail: rahman@umz.ac.ir
Received December 27, 2001. Accepted (revised) February 6, 2002 相似文献
2.
Gregor Radau 《Monatshefte für Chemie / Chemical Monthly》2003,134(7):1033-1036
Summary. The syntheses of dipeptide esters containing a C-terminal L-proline moiety using carbodiimides as coupling reagents strongly depend on the choice of appropriate conditions. Thus, the
use of DCC prefers the formation of the undesirable N,N′-dicyclohexylurea derivative 3 as a consequence of a CO → N-shift in the O-acyl isourea intermediate instead of the desired dipeptide ester 4. In our hands, only DIC was able to yield the desired product exclusively.
E-mail: radau@pharmazie.uni-greifswald.de
Received November 7, 2002; accepted December 4, 2002
Published online May 6, 2003 相似文献
3.
On the basis of a transition state conformation analysis, an attempt was made to explain the high chemoselectivity of intramolecular [4 + 2] cycloaddition in 3-alkyl-2,6-difuryl-N-maleylpiperidin-4-ones. It was shown that the thermal Diels–Alder reaction in these piperidine derivatives takes place through the “boat” conformation and leads to the formation of hydrogenated 1-alkyl-4-(2-furyl)-2H-8,10a-epoxy-pyrido[2,1-a]isoindol-2-ones. The alternative regioisomers, 3-alkyl-4-(2-furyl)-2H-8,10a-epoxy-pyrido[2,1-a]isoindol-2-ones, are hardly formed at all. At the same time, the intramolecular Diels–Alder reaction in the isostructural 3-alkyl-N-allyl-2,6-difurylpiperidin-4-ones, takes place non-regioselectively from the “chair” conformation. 相似文献
4.
Sanjay Senapoti Kamal Krishna Sarker Tapan Kumar Mondal Chittaranjan Sinha 《Transition Metal Chemistry》2006,31(3):293-298
2-(Methyl)-4-(arylazo)imidazole (RLH) (1, 2) are new series of azoimidazoles. Upon treatment of alkylhalide in dry THF in presence of NaH has synthesised 1-alkyl-2-(methyl)-4-(arylazo)imidazole
(RLR′) (3, 4). They belong to the azoimine family of N,N′-chelating ligand. They stabilize the Cu(I) oxidation state and we have synthesized [Cu(RLR′)2](ClO4) (5, 6). These complexes show a moderately intense visible band (500–600 nm) which has been assigned to 3d(Cu) → π*(ligand) transition. Ag(I) complexes of RLR′ (7, 8) are also very stable under ambient conditions and show weak transitions in the visible region. The Cu(I)-complexes show high
potential Cu(II)/Cu(I) redox couple > 0.4 V vs Ag, AgCl/Cl− reference electrode. All these complexes have been structurally characterized by 1H NMR spectroscopic data. 相似文献
5.
Heating 5,13-dihydro-11H-isoquino[3,2-b]quinazolin-11-one with isonicotinoyl chloride in pyridine gives 6-isonicotinoyl-5,13-dihydro-11H-isoquino[3,2-b]quinazolin-11-one. The 1-alkyl-4[(11-oxo-5,13-dihydro-11H-isoquino[3,2-b]quinazolin-6-yl)carbonyl]pyridinium iodides obtained by alkylation of 6-isonicotinoyl-5,13-dihydro-11H-isoquino[3,2-b]quinazolin-11-one using alkyl iodides in the presence of NaH are converted to 1′-R-spiro[7H,8H-2a,7a-diazacyclopenta[fg]naphthacene-2,4′(1′H)-pyridine]-1,8(2H)-diones. The chemical and spectroscopic properties of the spiro compounds obtained
were studied.
For Communication 32 see [1].
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 52–58, January, 2009. 相似文献
6.
Khosrow Jadidi Ramin Ghahremanzadeh Morteza Mehrdad Mohammad Ghanbari Hamid Arvin-Nezhad 《Monatshefte für Chemie / Chemical Monthly》2008,139(3):277-280
Summary. Novel N-alkyl-4-imino-1,4-dihydro-2H-3,1-benzoxazin-2-ones were synthesized in a single step by Baeyer–Villiger oxidation of N-alkyl-3-imino-2-indolinone derivatives in high yields. The structures of the products were determined by spectral data and
by X-ray diffraction. Besides their novel structures, these compounds may have important biological activities and industrial
applications. 相似文献
7.
Eberhard Reimann Wolfgang Erdle Eugen Hargasser Hermann Lotter 《Monatshefte für Chemie / Chemical Monthly》2002,133(7):1017-1030
Summary. The stereoselective synthesis of cis-ergoline is presented. Starting from rac-N-benzoyl tryptophan methyl ester, the key compound indolinylmethylpyridin-3-one was prepared via a seven-step reaction in good yield. Since its cyclization to the desired ergolinone failed, the key compound was reduced
to yield the two diastereomeric pyridin-3-ols; only one of them cyclized in trifluoromethanesulfonic acid, affording cis-ergoline. Catalytic hydrogenation of the latter gave N,N′-dimethyldihydroergoline, the X-ray crystallography of which revealed both the correct structure and identical relative configurations
at C-5a and C-6a (SS or RR). Hydroboration and subsequent perruthenate oxidation of the Δ9-ergoline provided access to the regioisomeric ergolinols and ergolinones.
Received December 27, 2001. Accepted January 15, 2002 相似文献
8.
Krishna C. Majumdar Subhojit Ghosh 《Monatshefte für Chemie / Chemical Monthly》2002,133(10):1317-1323
Summary. Regioselective heterocyclization of 3-(cyclohex-2′-enyl)-4-hydroxy-6-methyl pyran-2-one with various reagents afforded different
heterocycles. With N-iodosuccinimide in acetonitrile at 0–5°C it gave 6-methyl-9′-iodo-2′-oxabicyclo[3.3.1]nonano[3,2-c]pyran-2-one, with C5H5NHBr3 or C6H12N4HBr3 in CHCl3 at 0–5°C it furnished 6-methyl-9′-bromo-2′-oxabicyclo[3.3.1]nonano[3,2-c]pyran-2-one. Cold concentrated H2SO4 lead to 6-methyl-2′-oxabicyclo[3.3.1]nonano[3,2-c]pyran-2-one, whereas PdCl2(PhCN)2 in C6H6 at 80°C afforded 9-methyl benzofuro[3,2-c]pyran-2-one.
Corresponding author. E-mail: kcm@klyuniv.ernet.in
Received December 27, 2001. Accepted (revised) March 1, 2002 相似文献
9.
Mohamed El-Sayed Hardy Müller Gerd Rheinwald Heinrich Lang Stefan Spange 《Monatshefte für Chemie / Chemical Monthly》2003,134(3):361-370
Summary. N-(2′-Hydroxy-4′-N,N-dimethylaminobenzylidene)-4-nitroaniline [HDBN] has been used as a model for investigating intra- and intermolecular D–A (donor–acceptor) interactions in various environments
by means of UV/Vis spectroscopy. UV/Vis spectra of HDBN have been measured in various solvents, ethanolic solutions of different pH, adsorbed on silica, and in the solid state. A bathochromic shift of νmax is observed with increasing the dipolarity/polarizability and HBD (hydrogen bond donor) capacity of the solvent, which is
described by means of a multiple LSE (linear solvation energy) relationship in terms of the empirical Kamlet-Taft solvent polarity parameters. The adsorption of HDBN on Aerosil? 300-silica particles in non-HBA (hydrogen bond acceptor) solvents is explained in the same sense. Mobile protons and sol–gel
entrapping cause a hypsochromic shift due to protonation of the lone electron pair of the 4′-N,N-dimethylamino group. Hydroxide ions attack the 2′-hydroxy group which causes a bathochromic shift. A strong intramolecular
hydrogen bond between the 2′-hydroxyl hydrogen and the imine nitrogen atom is present in the solid-state structure causing
an unprecedented bathochromic shift.
Corresponding author. E-mail: stefan.spange@chemie.tu-chemnitz.de
Received July 8, 2002; accepted (revised) September 30, 2002 相似文献
10.
Alexander Kaiser Klaus K. Mayer Andreas Sellmer Wolfgang Wiegrebe 《Monatshefte für Chemie / Chemical Monthly》2003,134(3):343-354
Summary. The molecular ion 1 of N-(n-propoxy)benzaldimine I rearranges by an 1,5-H-shift to the δ-distonic ion 2 which subsequently cyclizes to the α-distonic ion 3. Homolytic cleavage of the N–O bond in 3 results in the δ-distonic ion 4 which expels CH2O leading to the β-distonic ion 5. Ion 5 is also formed from the molecular ions of tetrahydrooxazines II and III and from M+• of phenylazetidine IVa. In a subsequent step, ion 5 cyclizes to the N-protonated 3,4-dihydroisoquinolinium ion 6. The syntheses of II–IV and their derivatives are described.
Corresponding author. E-mail: wolfgang.wiegrebe@chemie.uni-regensburg.de
Received February 12, 2002; accepted (revised) April 9, 2002
RID="a"
ID="a" Dedicated to Prof. Dr. J. Knabe, Saarbrücken, Germany 相似文献
11.
V. V. Dotsenko S. G. Krivokolysko A. N. Chernega V. P. Litvinov 《Russian Chemical Bulletin》2007,56(5):1053-1062
Treatment of N-methylmorpholinium 4-R-6-amino-3,5-dicyano-1,4-dihydropyridine-2-thiolates (R = 2-ClC6H4 and 2-MeOC6H4) with primary amines in the presence of an excess of formaldehyde gave 13-R-8-thioxo-3,5,7,11-tetraazatricyclo[7.3.1.02,7]tridec-2-ene-1,9-dicarbonitrile derivatives in high yields (66–95%). In a similar way, aminomethylation of 3-R-10-amino-7,11-dicyano-9-aza-3-azoniaspiro[5.5]undeca-7,10-diene-8-thiolates
(R = Me and Et) afforded 1′-alkyl-8-thioxospiro[3,5,7,11-tetraazatricyclo[7.3.1.02,7]tridec-2-ene-13,4′-piperidine]-1,9-dicarbonitriles in 43–91% yields. Alternatively, these compounds were obtained by multicomponent
cyclocondensation of N-alkylpiperidin-4-ones, cyanothioacetamide, primary amines, and aqueous formaldehyde. The starting 3-R-10-amino-7,11-dicyano-9-aza-3-azoniaspiro[5.5]undeca-7,10-diene-8-thiolates
were prepared by a new method from N-alkylpiperidin-4-ones and cyanothioacetamide. The structure of 5,11-bis(4-ethoxyphenyl)-13-(2-methoxyphenyl)-8-thioxo-3,5,7,11-tetraazatricyclo[7.3.1.02,7]tridec-2-ene-1,9-dicarbonitrile was examined by X-ray diffraction analysis.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1014–1022, May, 2007. 相似文献
12.
Aminomethylation of 3,5-dicyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolates upon treatment with primary amines and excess
formaldehyde leads to 3,7-diazabicyclo[3.3.1]nonane derivatives. N-Methylmorpholinium 4-(2-chlorophenyl)-3,5-dicyano-6-oxo-1,4,5,6-tetrahydropyridine-2-thiolate was obtained by the reaction
of (E)-3-(2-chlorophenyl)-2-cyanoprop-2-enethioamide with 1-cyanoacetyl-3,5-dimethylpyrazole and N-methylmorpholine in acetone in quantitative yield.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2397–2400, December, 2007. 相似文献
13.
Ring opening in 2-alkyl-4,5-dihydrooxazoles by the action of azoles gave intermediate N-(2-azolylethyl)alkanamides, whose hydrolysis afforded N-(2-aminoethyl)azoles.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1781–1784, October, 2006. 相似文献
14.
Marek Burian Ladislav Omelka Silvie Ondrášová Vlasta Brezová 《Monatshefte für Chemie / Chemical Monthly》2003,134(4):501-508
Summary. Several N-phenyl substituted 1,4- and 1,2-phenylenediamines were oxidized using radicals and 3-chloroperbenzoic acid. EPR spectroscopy confirmed the generation of nitroxide radicals originating from the
oxidation of the bridging -NH-group. No radical products suggesting the simultaneous reaction with the NH2-group were observed. Only in the case of 1,4-phenylenediamine, a low concentration of nitroxide radical H–NO–C6H4–NH2 was obtained. In o-aminodiphenylnitroxide the steric effect of the NH2-group causes a partially asymmetrical spin density distribution in both phenyl rings.
Corresponding author. E-mail: omelka@fch.vutbr.cz
Received September 30, 2002; accepted October 4, 2002 相似文献
15.
M. R. Ganjali Tahereh Poursaberi Fatemeh Basiripour Masoud Salavati-Niassari Mohammad Yousefi Mojtaba Shamsipur 《Analytical and bioanalytical chemistry》2001,370(8):1091-1095
A PVC membrane electrode based on a cadmium–salen (N,N′-bis-salicylidene-1,2ethylenediamine) complex as an anion carrier is described. The electrode has an anti-Hofmeister selectivity
sequence with a preference for thiocyanate at pH 1.5–11.0. It has a linear response to thiocyanate from 1.0 × 10–6 to 1.0 × 10–1 mol L–1 with a slope of 59.1 ± 0.2 mV per decade, and a detection limit of 7 × 10–7 mol L–1. This electrode has high selectivity for thiocyanate relative to many common organic and inorganic anions. The proposed sensor
has a fast response time of approximately 15 s. It was applied to the determination of thiocyanate in a milk sample.
Received: 1 December 2000 / Revised: 19 April 2001 / Accepted: 30 April 2001 相似文献
16.
B. F. Kukharev V. K. Stankevich N. A. Lobanova G. R. Klimenko V. V. Stankevich E. V. Bragin 《Russian Journal of Organic Chemistry》2010,46(4):491-494
Condensation of N-(2-vinyloxyethyl)ethane-1,2-diamine with aromatic aldehydes gave mixtures of 2-aryl-1-(2-vinyloxyethyl)imidazolidines and
N-arylmethylidene-N′-(2-vinyloxyethyl)ethane-1,2-diamines in an overall yield of 79–84%, while analogous condensation with cyclic and acyclic
ketones resulted in the formation of only the corresponding Schiff bases (yield 53–83%). 相似文献
17.
A. M. Gapparov S. F. Aripova N. A. Razzakov V. U. Khuzhaev 《Chemistry of Natural Compounds》2008,44(6):743-744
The known alkaloid convolvidine and a new base conpropine, for which the structure N-propylconvolvine was proposed, were isolated from total alkaloids from the aerial part of Convolvulus subhirsutus.
Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 601–602, November–December, 2008. 相似文献
18.
Bis(dibenzylidenacetone)palladium is an efficient and highly selective catalyst for the formation ofN-(2,7-dimethylocta-2,7-dienyl)benzoimidazole in the allylation of benzoimidazole withN-(2,7-dimethylocta-2,7-dienyl)-N-methylpiperidinium iodide in the presence of NaH.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 357–360, February, 1999. 相似文献
19.
S. V. Chepyshev Yu. N. Chepysheva A. B. Ryabitskii A. V. Prosyanik 《Chemistry of Heterocyclic Compounds》2008,44(5):523-529
In vinyl nucleophilic substitution (SN
vin) with the hydrochlorides or 4-toluenesulfonates of primary arylamines 1-alkyl-3-alkylaminopyrrole-2,5-diones form the corresponding
1-alkyl-3-arylaminopyrrole-2,5-diones, which are also produced in situ from the corresponding arylaminofumarates and primary
alkylamines.
__________
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 668–675, May, 2008. 相似文献
20.
Alberto Bargagna Sergio Cafaggi Pietro Schenone 《Journal of heterocyclic chemistry》1980,17(3):507-511
Cycloaddition of dichloroketene to N,N-disubstituted 1-amino-4-methyl-1-penten-3-ones and 1-amino-4,4-dimethyl-1-penten-3-ones occurred in moderate to fair yield only in the case of aromatic N-substitution to give N,N-disubstituted 6-alkyl-4-amino-3,3-dichloro-3,4-dihydro-2H-pyran-2-ones, which were dehydrochlorinated with DBN to afford in good yield N,N-disubstituted 6-alkyl-4-amino-3-chloro-2H-pyran-2-ones. In the case of aliphatic N,N-disubstitution, cyclo-addition led directly to 6-alkyl-4-dialkylamino-3-chloro-2H-pyran-2-ones only for N,N-disubstituted 1-amino-4,4-dimethyl-1-penten-3-ones. The reaction between 1-dimethylamino-4-methyl-1-penten-3-one and dichloroketene gave 3-chloro-4-dimethylamino-3,6-dihydro-6-isopropylidene-2H-pyran-2-one in low yield. 相似文献