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1.
Katarzyna Guzow Mariusz Szabelski Joanna Malicka Wiesaw Wiczk 《Helvetica chimica acta》2001,84(5):1086-1092
A simple method of synthesis of a new, highly fluorescent amino acid derivative from the simple and generally available substrates 3‐nitro‐L ‐tyrosine and 1H‐indole‐3‐carbaldehyde is described. The obtained compound, N‐[(tert‐butoxy)carbonyl]‐3‐[2‐(1H‐indol‐3‐yl)benzoxazol‐5‐yl]‐L ‐alanine methyl ester ( 4 ), possesses a high fluorescence quantum yield. The described method illustrates a new possibility of synthesis of amino acid derivatives possessing desirable photophysical properties. 相似文献
2.
Giovanni Suter SvetlanaA. Stoykova Anthony Linden Heinz Heimgartner 《Helvetica chimica acta》2000,83(11):2961-2974
The synthesis of methyl N‐(1‐aza‐6‐oxaspiro[2.5]oct‐1‐en‐2‐yl)‐L ‐prolinate ( 1e ) has been performed by consecutive treatment of methyl N‐[(tetrahydro‐2H‐pyran‐4‐yl)thiocarbonyl]‐L ‐prolinate ( 5 ) with COCl2, 1,4‐diazabicyclo[2.2.2]octane (DABCO), and NaN3 (Scheme 1). As the first example of a novel class of dipeptide synthons, 1e has been shown to undergo the expected reactions with carboxylic acids and thioacids (Scheme 2). The successful preparation of the nonapeptide 16 , which is an analogue of the C‐terminal nonapeptide of the antibiotic Trichovirin I 1B, proved that 1e can be used in peptide synthesis as a dipeptide building block (Scheme 3). The structure of 7 has been established by X‐ray crystal‐structure analysis (Figs. 1 and 2). 相似文献
3.
Xiao‐Feng Yang Guang‐You Zhang Yan Zhang Jin‐Yan Zhao Xiang‐Bo Wang 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(4):o262-o264
The title compound, C25H30NO2+·Cl−, has been synthesized, and the crystal structure shows that it is mainly stabilized through intermolecular N—H·Cl and O—H·Cl and intramolecular N—H·O hydrogen bonds. The absolute configuration of the new stereogenic center (the C atom adjacent to the N atom on the phenol side) was determined to have an R configuration. 相似文献
4.
Abhijit Mitra Pamela J. Seaton Kraig A. Wheeler 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(9):o581-o582
The title new diquinaldine derivative, C27H24N4, forms molecular assemblies organized by intermolecular quinoline π–π stacking [3.356 (3) and 3.440 (3) Å] and both inter‐ and intramolecular N—H⋯N hydrogen bonds [3.039 (3)–3.104 (3) Å and 129 (2)–172 (2)°]. The combination of such interactions provides readily definable contacts that propagate along each crystallographic axis. 相似文献
5.
P. Haranath V. Sreedhar Kumar C. Suresh Reddy C. Naga Raju C. Devendranath Reddy 《Journal of heterocyclic chemistry》2007,44(2):369-373
Substituted benzoxazaphosphorin 2‐yl ureas were synthesized by reacting 2‐(4‐fluoro‐phenylamino)‐methylphenol (4) with different carbamidophosphoric acid dichlorides (3) in the presence of triethylamine in dry toluene at 45‐50 °C and characterized by spectral data. These compounds were found to possess good antimicrobial activity. 相似文献
6.
Three copper(II) complexes, [Cu2(OAc)4L2] · 2CH3OH ( 1 ), [CuBr2L′2(CH3OH)] · CH3OH ( 2a ), and [CuBr2L′2(DMSO)] · 0.5CH3OH ( 2b ) {L = N‐(9‐anthracenyl)‐N′‐(3‐pyridyl)urea and L′ = N‐[10‐(10‐methoxy‐anthronyl)]‐N′‐(3‐pyridyl)urea} have been synthesized by the reaction of L with the corresponding copper(II) salts. Complex 1 shows a dinuclear structure with a conventional “paddlewheel” motif, in which four acetate units bridge the two CuII ions. In complexes 2a and 2b , the anthracenyl ligand L has been converted to an anthronyl derivative L′, and the central metal ion exhibits a distorted square pyramidal arrangement, with two pyridyl nitrogen atoms and two bromide ions defining the basal plane and the apical position is occupied by a solvent molecule (CH3OH in 2a and DMSO in 2b ). 相似文献
7.
8.
Gilles Muller Boris Schmidt Jan Jii
ek Jean‐Claude G. Bünzli Kurt J. Schenk 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o353-o356
L4, or 3‐[2,6‐bis(diethylcarbamoyl)pyridin‐4‐yl]‐N‐(tert‐butoxycarbonyl)alanine methyl ester, C24H38N4O6, crystallizes in neat [010] laths stabilized by abundant intra‐ and intermolecular hydrogen bonds. The strongest of these form [010] chains of molecules, thus rationalizing the fastest growth direction, while the slowest direction coincides with the normal to the (110) layers, which are linked by very weak hydrogen bonds. There exist two independent molecules, the distances and bond angles of which differ in a random manner only. The torsion and dihedral angles, however, differ so as to achieve optimal packing. The influence of the chiral group in the 4‐position of the pyridine ring on the helical wrapping and on the ensuing diastereomeric induction is briefly discussed. 相似文献
9.
Oscar F. Vazquez‐Vuelvas Julia V. Hernndez‐Madrigal Armando Pineda‐Contreras Simn Hernndez‐Ortega Reyna Reyes‐Martínez David Morales‐Morales 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(3):175-180
Two isomeric pyridine‐substituted norbornenedicarboximide derivatives, namely N‐(pyridin‐2‐yl)‐exo‐norbornene‐5,6‐dicarboximide, (I), and N‐(pyridin‐3‐yl)‐exo‐norbornene‐5,6‐dicarboximide, (II), both C14H12N2O4, have been crystallized and their structures unequivocally determined by single‐crystal X‐ray diffraction. The molecules consist of norbornene moieties fused to a dicarboximide ring substituted at the N atom by either pyridin‐2‐yl or pyridin‐3‐yl in an anti configuration with respect to the double bond, thus affording exo isomers. In both compounds, the asymmetric unit consists of two independent molecules (Z′ = 2). In compound (I), the pyridine rings of the two independent molecules adopt different conformations, i.e. syn and anti, with respect to the methylene bridge. The intermolecular contacts of (I) are dominated by C—H...O interactions. In contrast, in compound (II), the pyridine rings of both molecules have an anti conformation and the two independent molecules are linked by carbonyl–carbonyl interactions, as well as by C—H...O and C—H...N contacts. 相似文献
10.
An efficient one‐pot synthesis of 3‐[(4,5‐dihydro‐1H‐pyrrol‐3‐yl)carbonyl]‐2H‐chromen‐2‐one (=3‐[(4,5‐dihydro‐1H‐pyrrol‐3yl)carbonyl]‐2H‐1‐benzopyran‐2‐one) derivatives 4 by a four‐component reaction of a salicylaldehyde 1 , 4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one, a benzylamine 2 , and a diaroylacetylene (=1,4‐diarylbut‐2‐yne‐1,4‐dione) 3 in EtOH is reported. This new protocol has the advantages of high yields (Table), and convenient operation. The structures of these coumarin (=2H‐1‐benzopyran‐2‐one) derivatives, which are important compounds in organic chemistry, were confirmed spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme 2). 相似文献
11.
Synthesis of 3‐(ω‐Hydroxyalkoxy)isobenzofuran‐1(3H)‐ones by Trifluoroacetic Acid‐Mediated Lactonization of tert‐Butyl 2‐(1,3‐Dioxol‐2‐yl)‐ or 2‐(1,3‐Dioxan‐2‐yl)benzoates 下载免费PDF全文
An efficient two‐step method for the preparation of 3‐(2‐hydroxyethoxy)‐ or 3‐(3‐hydroxypropoxy)isobenzofuran‐1(3H)‐ones 3 has been developed. Thus, the reaction of 1‐(1,3‐dioxol‐2‐yl)‐ or 1‐(1,3‐dioxan‐2‐yl)‐2‐lithiobenzenes, generated in situ by the treatment of 1‐bromo‐2‐(1,3‐dioxol‐2‐yl)‐ or 1‐bromo‐2‐(1,3‐dioxan‐2‐yl)benzenes 1 with BuLi in THF at ?78°, with (Boc)2O afforded tert‐butyl 2‐(1,3‐dioxol‐2‐yl)‐ or 2‐(1,3‐dioxan‐2‐yl)benzoates 2 , which can subsequently undergo facile lactonization on treatment with CF3COOH (TFA) in CH2Cl2 at 0° to give the desired products in reasonable yields. 相似文献
12.
《Journal of heterocyclic chemistry》2017,54(6):3632-3645
Schiff base complexes of Cu(II), Ni(II), Cd(II), and Zn(II) with 3‐(2‐(2‐oxo‐2H ‐chromene‐3‐carbonyl)hydrazono)‐N ‐(pyridin‐2‐yl)butanamide (H2L) were produced. The synthesized compounds were deduced by elemental analysis, molar conductance, magnetic susceptibility, and spectroscopic techniques. The geometry of the prepared complexes was estimated by applying DFT method. Also, Cu(II) and Zn(II) were separated using a simple, quick, and low‐cost quantitative flotation technique preceding to their determinations using atomic absorption spectrophotometric (AAS). Additionally, the biological activities (antimicrobial, antioxidant, and cytotoxic) of isolated compounds were carried out. 相似文献
13.
Rahul Banerjee Samir Kumar Maji Arindam Banerjee 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1120-1121
The title compound, C25H44N4O5, exhibits a turn with the main chain reversing direction, held together by an intramolecular N—H?O hydrogen bond. In the urea fragment, a notable amide C—N bond between the carboxyl C and the tertiary N atom shows marked single‐bond character [1.437 (2) Å]. The dihedral angle of the β‐alanyl residue, centrally located in the turn, is gauche [69.2 (2)°]. The packing is mediated by two intermolecular hydrogen bonds and van der Waals contacts involving the methyl moieties and the cyclohexyl rings. 相似文献
14.
Xu‐Xia Sun Shu‐Lan Ma Hai‐Bo Huang Chuan‐Min Qi 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(2):o87-o88
In the crystal structure of the title compound, C21H21NO2, strong N—H⋯O and O—H⋯O hydrogen bonds exist. The keto–amine form is favoured over the enol–imine form in the tautomerism. Six‐membered chelate rings formed by intramolecular hydrogen bonds increase the stability of the whole molecule. Intermolecular hydrogen bonds link adjacent units together, forming an infinite one‐dimensional chain parallel to the a axis. 相似文献
15.
Cara E. Brocklehurst Markus Furegati J. Constanze D. Müller‐Hartwieg Flavio Ossola Luigi La Vecchia 《Helvetica chimica acta》2010,93(2):314-323
α‐Aminomethylation of (R)‐DIOZ‐alkylated (DIOZ=4‐isopropyl‐5,5‐diphenyloxazolidin‐2‐one) substrates is a key step in the asymmetric synthesis of β2‐amino acids, but it is unfortunately often accompanied by formation of transcarbamation by‐products. Aminomethylation was tested using a range of electrophiles, and the amount of by‐product formation was assessed in each case. Benzyl N‐[(benzyloxy)methyl]carbamate electrophile 3d is unable to form this by‐product due to its inherent benzyl substitution. Use of electrophile 3d showed an improved impurity profile in aminomethylation, thus leading to easier intermediate purification. 相似文献
16.
Jia‐Xiang Yang Yu‐Peng Tian Qing‐Liang Liu Yong‐Shu Xie Hoong‐Kun Fun Suchada Chantrapromma Ibrahim Abdul Razak 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):m43-m44
In the title compound, [Fe(C5H5)(C16H12N3OS)], the 8‐aminoquinoline and acylthiourea moieties are almost planar. There are two perpendicular arrangements of the molecules in the crystal with slightly different conformations. The two cyclopentadienyl rings in each molecule are parallel and eclipsed. 相似文献
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18.
Eleven novel 5‐methyl‐2‐[(un)substituted phenyl]‐4‐{4,5‐dihydro‐3‐[(un)substituted phenyl]‐5‐(1,2,3,4‐tetrahydroisoquinoline‐2‐yl)pyrazol‐1‐yl}‐oxazole derivatives were synthesized and characterized by elemental analysis, ESI‐MS, 1H NMR and 13C NMR. All of the compounds have been screened for their antiproliferative activities against PC‐3 cell (human prostate cancer) and A431 cell (human epidermoid carcinoma cancer) lines in vitro. The results revealed that compounds 4g , 4j and 4k exhibited the strong inhibitory activities against the PC‐3 cell lines (with IC50 values of 2.8±0.11, 3.1±0.10 and 3.0±0.06 μg/mL, respectively). 相似文献
19.
A series of new N‐benzoyl‐N‐tert‐butyl‐N′‐(β‐triphenylgermyl)propionylhydrazines were synthesized by the condensation reaction of β‐triphenylgermyl propanoic acid with N‐benzoyl‐N‐tert‐butylhydrazines in good yields by using N,N′‐dicyclohexylcorbodiimide as dehydrating agent. These title compounds were evaluated for molting hormone mimicking activity. The results of bioassay showed that the compounds exhibit moderate larvicidal activity, and toxicity assays indicated that the title compounds can induce a premature, abnormal and lethal larval molt. We found that the title compounds possess potential anticancer activities in vitro. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
20.
Hyun‐A Chung Young‐Jin Kang D. H. Kweon Woo Song Lee Yong‐Jin Yoon 《Journal of heterocyclic chemistry》2000,37(6):1443-1446
This paper presents the synthesis of 1‐[(pyrazol‐3‐yl)methyl]pyridazin‐6‐ones from ethyl 4‐(4,5‐dichloro‐6‐oxopyridazin‐1‐yl)‐3‐oxobutanoate. 相似文献