共查询到20条相似文献,搜索用时 46 毫秒
1.
Patrik Pařík Josef Jansa Sylva Holešová Aleš Marek Věra Klimešová 《Journal of heterocyclic chemistry》2013,50(4):903-910
Reactivity of 2‐(4‐hydroxyphenyl)‐1H‐imidazoline and 2‐(4‐hydroxyphenyl)‐1H‐imidazole toward substituted phenyl isocyanates was studied. When mentioned imidazoline was treated with 2.5 equiv of substituted phenyl isocyanate, three N,O‐dicarboxamides were prepared (substituents are H, 4‐NO2, and 4‐CH3). Subsequently, N,O‐diacetylated 2‐(4‐hydroxyphenyl)‐1H‐imidazoline was prepared and selective deprotection method was developed for preparation of 1‐acetyl‐2‐(4‐hydroxyphenyl)‐1H‐imidazoline using diethylamine in acetone. Six carbamates derived from this imidazoline were then prepared using 1.1 equiv of substituted phenyl isocyanates (substituents are H, 4‐CH3, 4‐OCH3, 4‐NO2, 4‐CN, and 3‐CF3). Finally, two carbamates were prepared from 2‐(4‐hydroxyphenyl)‐1H‐imidazole (substituents are 4‐NO2 and 4‐CN). No reactivity to imidazole ring was observed in this case. Eight derivatives were subjected to antimycobacterial screening. Concurrently, reactivity of 2‐(2‐aminophenyl)‐ and 2‐(2‐hydroxyphenyl)‐1H‐imidazole toward aliphatic and aromatic isocyanates was studied. Eight ureas were prepared using equivalent mixture of 2‐(2‐aminophenyl)‐1H‐imidazole and isocyanate (Et, Pr, isoPr, terc‐Bu, Cy, Ph, 4‐CH3C6H4, 4‐CNC6H4). Similar attempts to obtain related carbamates from 2‐(2‐hydroxyphenyl)‐1H‐imidazole lead only to three substituted phenyl carbamates (substituents are 4‐CH3, 4‐NO2, and 4‐CN). In both cases, no reactivity to imidazole ring was observed again. 相似文献
2.
David J. Nielsen Claudio Pettinari Brian W. Skelton Allan H. White 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(8):o542-o544
Low‐temperature studies of the simple variously substituted imidazole types 4‐phenyl‐1H‐imidazole, C9H8N2, 1‐benzyl‐1H‐imidazole, C10H10N2, and 1‐mesityl‐1H‐imidazole, C12H14N2, extend comparisons between parent imidazole species and their derivatives, the pronounced double‐bond localization opposite the substituted N atom common to simple neutral species being redistributed aromatically on protonation. 相似文献
3.
Jan W. Bats Peter Schell Joachim W. Engels 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(5):529-533
Crystal structures are reported for three substituted 1H‐imidazole‐4,5‐dicarbonitrile compounds used as catalysts for the coupling reaction of nucleoside methyl phosphonamidites, namely 2‐(3′,5′‐dimethylbiphenyl‐2‐yl)‐1H‐imidazole‐4,5‐dicarbonitrile, C19H14N4, (I), 2‐(2′,4′,6′‐trimethylbiphenyl‐2‐yl)‐1H‐imidazole‐4,5‐dicarbonitrile, C20H16N4, (II), and 2‐[8‐(3,5‐dimethylphenyl)naphthalen‐1‐yl]‐1H‐imidazole‐4,5‐dicarbonitrile, C23H16N4, (III). The asymmetric unit of (I) contains two independent molecules with similar conformations. There is steric repulsion between the imidazole group and the terminal phenyl group in all three compounds, resulting in the nonplanarity of the molecules. The naphthalene group of (III) shows significant deviation from planarity. The C—N bond lengths in the imidazole rings range from 1.325 (2) to 1.377 (2) Å. The molecules are connected into zigzag chains by intermolecular N—H...Nimidazole [for (I)] or N—H...·Ncyano [for (II) and (III)] hydrogen bonds. 相似文献
4.
Guo-Xia Jin Tian-Chao You Jian-Ping Ma 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(12):1690-1697
The new asymmetrical organic ligand 2‐{4‐[(1H‐imidazol‐1‐yl)methyl]phenyl}‐5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazole ( L , C17H13N5O), containing pyridine and imidazole terminal groups, as well as potential oxdiazole coordination sites, was designed and synthesized. The coordination chemistry of L with soft AgI, CuI and CdII metal ions was investigated and three new coordination polymers (CPs), namely, catena‐poly[[silver(I)‐μ‐2‐{4‐[(1H‐imidazol‐1‐yl)methyl]phenyl}‐5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazole] hexafluoridophosphate], {[Ag( L )]PF6}n, catena‐poly[[copper(I)‐di‐μ‐iodido‐copper(I)‐bis(μ‐2‐{4‐[(1H‐imidazol‐1‐yl)methyl]phenyl}‐5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazole)] 1,4‐dioxane monosolvate], {[Cu2I2( L )2]·C4H8O2}n, and catena‐poly[[[dinitratocopper(II)]‐bis(μ‐2‐{4‐[(1H‐imidazol‐1‐yl)methyl]phenyl}‐5‐(pyridin‐4‐yl)‐1,3,4‐oxadiazole)]–methanol–water (1/1/0.65)], {[Cd( L )2(NO3)2]·2CH4O·0.65H2O}n, were obtained. The experimental results show that ligand L coordinates easily with linear AgI, tetrahedral CuI and octahedral CdII metal atoms to form one‐dimensional polymeric structures. The intermediate oxadiazole ring does not participate in the coordination interactions with the metal ions. In all three CPs, weak π–π interactions between the nearly coplanar pyridine, oxadiazole and benzene rings play an important role in the packing of the polymeric chains. 相似文献
5.
Vladimir N. Nesterov Elena A. Viltchinskaia 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(5):616-618
The structures of the title compounds, C15H13N3O4, (I), and C16H15N3O5 [IUPAC name: ethyl 6‐amino‐5‐cyano‐2‐methyl‐4‐(3‐nitrophenyl)‐4H‐pyrano‐3‐carboxylate], (II), are very similar, with the heterocyclic rings adopting boat conformations. The pseudo‐axial m‐nitrophenyl substituents are rotated by 84.0 (1) and 98.7 (1)° in (I) and (II), respectively, with respect to the four coplanar atoms of the boat. The dihedral angles between the phenyl rings and nitro groups are 12.1 (2) and 8.4 (2)° in (I) and (II), respectively. The two compounds have similar patterns of intermolecular N—H?O and N—H?N hydrogen bonding, which link molecules into infinite tapes along b . 相似文献
6.
Caroline Charlier Bernadette Norberg Laurence Goossens Jean‐Pierre Hnichart Franois Durant 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(9):o648-o652
Three related compounds containing a pyrazole moiety with vicinal phenyl rings featuring a methylsulfonyl substituent are described, namely 3‐methyl‐1‐[4‐(methylsulfonyl)phenyl]‐5‐phenyl‐1H‐pyrazole, C17H16N2O2S, ethyl 1‐[4‐(methylsulfonyl)phenyl]‐5‐phenyl‐1H‐pyrazole‐3‐carboxylate, C19H18N2O4S, and 1‐[4‐(methylsulfonyl)phenyl]‐3‐[3‐(morpholino)phenoxymethyl]‐5‐phenyl‐1H‐pyrazole, C27H27N3O4S. The design of these compounds was based on celecoxib, a selective cyclooxygenase‐2 (COX‐2) inhibitor, in order to study the influence of various substituents on COX‐2 and 5‐lipoxygenase (5‐LOX) inhibition. 相似文献
7.
Bernardo Masci Stefano Levi Mortera Maurizio Varrone Pierre Thury 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(11):o649-o651
Two compounds containing 1,3‐benzodioxin groups are reported, namely (±)‐6‐tert‐butyl‐8‐hydroxymethyl‐2‐phenyl‐4H‐1,3‐benzodioxin, C19H22O3, (I), and 2,2,2′,2′,6,6′‐hexamethyl‐8,8′‐methylenebis(4H‐1,3‐benzodioxin), C23H28O4, (II).The hydroxy groups of neighbouring molecules in (I) are hydrogen bonded to each other, giving rise to double‐row chains. The molecule in (II) adopts a `butterfly' conformation, with the O atoms in distal positions. In both compounds, the dioxin rings are in distorted half‐chair conformations. 相似文献
8.
Construction of Four Coordination Polymers based on 2‐[4‐(Pyridine‐4‐yl)phenyl]‐1H‐imidazole‐4,5‐dicarboxylic Acid
下载免费PDF全文
![点击此处可从《无机化学与普通化学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Song‐Liang Cai Sha Wang Zi‐Hao He Kai Zhang Mei‐Lin Li Jun Fan Sheng‐Run Zheng Wei‐Guang Zhang 《无机化学与普通化学杂志》2017,643(9):593-600
The imidazole‐based dicarboxylate ligand 2‐(4‐(pyridin‐4‐yl)phenyl)‐1H‐imidazole‐4,5‐dicarboxylic acid (H3PyPhIDC), was synthesized and its coordination chemistry was studied. Solvothermal reactions of CaII, MnII, CoII, and NiII ions with H3PyPhIDC produced four coordination polymers, [Ca(μ3‐HPyPhIDC)(H2O)2]n ( 1 ), {[M3(μ2‐H2PyPhIDC)2(μ3‐HPyPhIDC)26(H2O)2] · 6H2O}n [M = Mn ( 2 ), Co ( 3 )], and {[Ni(μ3‐HPyPhIDC)(H2O)] · H2O}n ( 4 ). Compounds 1 – 4 were analyzed by IR spectroscopy, elemental analyses, and single‐crystal and powder X‐ray diffraction. Compound 1 displays a one‐dimensional (1D) infinite chain. Compounds 2 and 3 are of similar structure, showing 2D network structures with a (4,4) topology based on trinuclear clusters. Compound 4 has another type of 2D network structure with a 3‐connected (4.82) topology. The results revealed that the structural diversity is attributed to the coordination numbers and geometries of metal ions as well as the coordination modes and conformations of H3PyPhIDC. Moreover, the thermogravimetric analyses of all the compounds as well as luminescence properties of the H3PyPhIDC ligand and compound 1 were also studied. 相似文献
9.
The reaction of 1H‐imidazole‐4‐carbohydrazides 1 , which are conveniently accessible by treatment of the corresponding esters with NH2NH2?H2O, with isothiocyanates in refluxing EtOH led to thiosemicarbazides (=hydrazinecarbothioamides) 4 in high yields (Scheme 2). Whereas 4 in boiling aqueous NaOH yielded 2,4‐dihydro‐3H‐1,2,4‐triazole‐3‐thiones 5 , the reaction in concentrated H2SO4 at room temperature gave 1,3,4‐thiadiazol‐2‐amines 6 . Similarly, the reaction of 1 with butyl isocyanate led to semicarbazides 7 , which, under basic conditions, undergo cyclization to give 2,4‐dihydro‐3H‐1,2,4‐triazol‐3‐ones 8 (Scheme 3). Treatment of 1 with Ac2O yielded the diacylhydrazine derivatives 9 exclusively, and the alternative isomerization of 1 to imidazol‐2‐ones was not observed (Scheme 4). It is important to note that, in all these transformations, the imidazole N‐oxide residue is retained. Furthermore, it was shown that imidazole N‐oxides bearing a 1,2,4‐triazole‐3‐thione or 1,3,4‐thiadiazol‐2‐amine moiety undergo the S‐transfer reaction to give bis‐heterocyclic 1H‐imidazole‐2‐thiones 11 by treatment with 2,2,4,4‐tetramethylcyclobutane‐1,3‐dithione (Scheme 5). 相似文献
10.
Kamal M. El‐Shaieb 《中国化学会会志》2007,54(5):1353-1358
When 2,3‐dichloro‐1,4‐naphthoquinone (DCHNQ) ( 1 ) is allowed to react with 1‐phenylbiguanide (PBG) ( 2 ), 4‐chloro‐2,5‐dihydro‐2,5‐dioxonaphtho[1,2‐d]imidazole‐3‐carboxylic acid phenyl amide ( 4 ), 6‐chloro‐8‐phenylamino‐9H‐7,9,11‐triaza‐cyclohepta[a]naphthalene‐5,10‐dione ( 5 ) and 4‐dimethyl‐amino‐5,10‐dioxo‐2‐phenylimino‐5,10‐dihydro‐2H‐benzo[g]quinazoline‐1‐carboxylic acid amide ( 6 ) were obtained. While on reacting 1 with 2‐guanidinebenzimidazole (GBI) ( 3 ) the products are 3‐(1H‐benzoimidazol‐2‐yl)‐4‐chloro‐3H‐naphtho[1,2‐d]imidazole‐2,5‐dione ( 7 ) and 3‐[3‐(1H‐benzoimidazol‐2‐yl)‐ureido]‐1,4‐dioxo‐1,4‐dihydronaphthalene‐2‐carboxylic acid dimethylamide ( 8 ). 相似文献
11.
Kiran S. Hon Hemantkumar N. Akolkar Bhausaheb K. Karale 《Journal of heterocyclic chemistry》2019,56(6):1780-1786
A series of novel 1‐methyl‐3‐(4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles was synthesized in three steps from 5‐(1‐methyl‐1H‐indazol‐3‐yl)‐4‐phenyl‐2H‐1,2,4‐triazole‐3(4H)‐thiones. 5‐(1‐Methyl‐1H‐indazol‐3‐yl)‐4‐phenyl‐2H‐1,2,4‐triazole‐3(4H)‐thiones were converted into 1‐methyl‐3‐(5‐(methylsulfonyl)‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles upon methylation followed by treatment with aq. KMnO4. The reaction of 1‐methyl‐3‐(5‐(methylsulfonyl)‐4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles with Raney nickel resulted in desulphonylation to afford corresponding 1‐methyl‐3‐(4‐phenyl‐4H‐1,2,4‐triazol‐3‐yl)‐1H‐indazoles. All the new synthesized compounds were characterized by spectral techniques. 相似文献
12.
Agnieszka Majchrzak Aleksandra Janczak Grzegorz Mlosto Anthony Linden Heinz Heimgartner 《Helvetica chimica acta》2003,86(6):2272-2283
The smooth reaction of 3‐chloro‐3‐(chlorosulfanyl)‐2,2,4,4‐tetramethylcyclobutanone ( 3 ) with 3,4,5‐trisubstituted 2,3‐dihydro‐1H‐imidazole‐2‐thiones 8 and 2‐thiouracil ( 10 ) in CH2Cl2/Et3N at room temperature yielded the corresponding disulfanes 9 and 11 (Scheme 2), respectively, via a nucleophilic substitution of Cl? of the sulfanyl chloride by the S‐atom of the heterocyclic thione. The analogous reaction of 3‐cyclohexyl‐2,3‐dihydro‐4,5‐diphenyl‐1H‐imidazole‐2‐thione ( 8b ) and 10 with the chlorodisulfanyl derivative 16 led to the corresponding trisulfanes 17 and 18 (Scheme 4), respectively. On the other hand, the reaction of 3 and 4,4‐dimethyl‐2‐phenyl‐1,3‐thiazole‐5(4H)‐thione ( 12 ) in CH2Cl2 gave only 4,4‐dimethyl‐2‐phenyl‐1,3‐thiazol‐5(4H)‐one ( 13 ) and the trithioorthoester derivative 14 , a bis‐disulfane, in low yield (Scheme 3). At ?78°, only bis(1‐chloro‐2,2,4,4‐tetramethyl‐3‐oxocyclobutyl)polysulfanes 15 were formed. Even at ?78°, a 1 : 2 mixture of 12 and 16 in CH2Cl2 reacted to give 13 and the symmetrical pentasulfane 19 in good yield (Scheme 5). The structures of 11, 14, 17 , and 18 have been established by X‐ray crystallography. 相似文献
13.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(8):967-973
Crystals of poly[[aqua[μ3‐4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylato‐κ5O1O1′:N3,O4:O5][μ4‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylato‐κ7N3,O4:O4,O4′:O1,O1′:O1]cadmium(II)] monohydrate], {[Cd2(C15H14N2O4)(C16H14N2O6)(H2O)]·H2O}n or {[Cd2(Hcpimda)(cpima)(H2O)]·H2O}n, (I), were obtained from 1‐(4‐carboxybenzyl)‐2‐propyl‐1H‐imidazole‐4,5‐dicarboxylic acid (H3cpimda) and cadmium(II) chloride under hydrothermal conditions. The structure indicates that in‐situ decarboxylation of H3cpimda occurred during the synthesis process. The asymmetric unit consists of two Cd2+ centres, one 4‐carboxy‐1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐5‐carboxylate (Hcpimda2−) anion, one 1‐(4‐carboxylatobenzyl)‐2‐propyl‐1H‐imidazole‐4‐carboxylate (cpima2−) anion, one coordinated water molecule and one lattice water molecule. One Cd2+ centre, i.e. Cd1, is hexacoordinated and displays a slightly distorted octahedral CdN2O4 geometry. The other Cd centre, i.e. Cd2, is coordinated by seven O atoms originating from one Hcpimda2− ligand and three cpima2− ligands. This Cd2+ centre can be described as having a distorted capped octahedral coordination geometry. Two carboxylate groups of the benzoate moieties of two cpima2− ligands bridge between Cd2 centres to generate [Cd2O2] units, which are further linked by two cpima2− ligands to produce one‐dimensional (1D) infinite chains based around large 26‐membered rings. Meanwhile, adjacent Cd1 centres are linked by Hcpimda2− ligands to generate 1D zigzag chains. The two types of chains are linked through a μ2‐η2 bidentate bridging mode from an O atom of an imidazole carboxylate unit of cpima2− to give a two‐dimensional (2D) coordination polymer. The simplified 2D net structure can be described as a 3,6‐coordinated net which has a (43)2(46.66.83) topology. Furthermore, the FT–IR spectroscopic properties, photoluminescence properties, powder X‐ray diffraction (PXRD) pattern and thermogravimetric behaviour of the polymer have been investigated. 相似文献
14.
A. Subbiah Pandi D. Velmurugan S. Shanmuga Sundara Raj Hoong‐Kun Fun P. R. Seshadri D. Thirumalai 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(7):821-824
10‐(4‐Fluorophenyl)‐3,3,6,6,9‐pentamethyl‐3,4,6,7,9,10‐hexahydroacridine‐1,8(2H,5H)‐dione, C24H28FNO2, (I), crystallizes with two crystallographically independent molecules (which differ slightly in conformation), while 10‐(4‐fluorophenyl)‐9‐propyl‐3,3,6,6‐tetramethyl‐3,4,6,7,9,10‐hexahydroacridine‐1,8(2H,5H)‐dione, C26H32FNO2, (II), crystallizes with one molecule per asymmetric unit. In both structures, the central ring in the acridine moiety is in a sofa conformation, while the outer rings adopt intermediate half‐chair/sofa conformations. The central pyridine ring is orthogonal to the substituted phenyl ring. In both structures, the packing of the crystal is stabilized by C—H?O intermolecular hydrogen bonds. 相似文献
15.
Yan Wu Gui‐Ge Hou Jian‐Ping Ma Yu‐Bin Dong 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(6):m163-m165
The title molecular complex, [CoCl2(C22H18N6O)], features a novel 18‐membered Co‐containing metallocycle. The CoII atom lies in a fairly regular tetrahedral geometry defined by two imidazole N‐atom donors from one 2,5‐bis[3‐(1H‐1,3‐imidazol‐1‐ylmethyl)phenyl]‐1,3,4‐oxadiazole (L) ligand and two chloride anions. The coordinating orientation of the L ligand plays an important role in constructing the metallocycle complex. The complexes form a three‐dimensional supramolecular assembly via nonclassical C—H...Cl and C—H...N hydrogen bonds and π–π interactions. 相似文献
16.
Viktor Kettmann Jan Svtlík Jií Kubita 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(6):o431-o433
In the title compound, C16H18N6O, an N‐carbonylimidazole derivative of pyrazoline‐1‐carboximidamide, the π‐electron density of the N atom in the 1‐position on the pyrazoline ring is delocalized through the amidine moiety and the adjacent carbonyl group. The imidazole ring, though coplanar with the rest of the molecule, is deconjugated. The pyrazoline ring adopts a flat‐envelope conformation, having the substituted phenyl ring oriented perpendicular to the mean plane of the heterocycle. Both of the two potential hydrogen‐bond donors are involved in intramolecular hydrogen‐bonding interactions. 相似文献
17.
New Chiral and Achiral Imines and Bisimines Derived from 2‐Phenyl‐1H‐imidazole‐4‐carbaldehyde. Synthesis,Structural Studies and Complexation Stability Constants
下载免费PDF全文
![点击此处可从《Journal of heterocyclic chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Synthesis and properties of new imines and bisimines derived from 2‐phenyl‐1H‐imidazole‐4‐carbaldehyde and amines/diamines were studied. (2‐Phenyl‐1H‐imidazole‐4‐yl)methanol was oxidized to 2‐phenyl‐1H‐imidazole‐4‐carbaldehyde with better yield 55% by the modification of literature procedure. This aldehyde was condensed with the following achiral and chiral amines or 1,2‐diamines: ethanamine, propan‐1‐amine, butan‐1‐amine, 2‐methylpropan‐1‐amine, cyclohexanamine, (2R)‐ and (2S)‐3‐methylbutan‐2‐amine, (1R)‐ and (1S)‐1‐cyclohexylethanamine, (S)‐1‐aminopropan‐2‐ol, (S)‐1‐(2‐phenyl‐1H‐imidazol‐4‐yl)ethanamine, (S)‐1‐(2‐phenyl‐1H‐imidazol‐4‐yl)‐2‐methylpropan‐1‐amine, (S)‐1‐(2‐phenyl‐1H‐imidazol‐4‐yl)‐3‐methylbutan‐1‐amine, ethane‐1,2‐diamine, and (1R,2R)‐ and (1S,2S)‐cyclohexane‐1,2‐diamine. Sixteen condensation products, especially chiral imines and bisimines, were prepared by founded procedures in 45–99% of yields and characterized by the 1H NMR spectroscopy in solution, mass spectrometry, and elemental analyses. The optical rotation values in the case of chiral ones were also observed. Stability constants of Cu(II) complexes of selected prepared imines/bisimines were determined. 相似文献
18.
Sankar Prasad Dey Dilip Kumar Dey Asok Kumar Mallik Lutz Dahlenburg 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o321-o322
The title compound, 2‐hydroxyphenyl 5‐(pyrrol‐2‐yl)‐3H‐pyrrolizin‐6‐yl ketone, C18H14N2O2, was isolated from the base‐catalyzed 1:2 condensation of 2‐hydroxyacetophenone with pyrrole‐2‐carbaldehyde. The pyrrole N—H and hydroxybenzoyl O—H groups are hydrogen bonded to the benzoyl O atom. The allylic C=C double bond of the 3H‐pyrrolizine system is located between ring positions 1 and 2, the C atom at position 3 (adjacent to the N atom) being single bonded. 相似文献
19.
Bruno Dacunha‐Marinho Ana Martínez Ramn J. Estvez 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(6):o353-o356
The title flavonoid [systematic name: (2S)‐7‐hydroxy‐5‐methoxy‐6,8‐dimethyl‐2‐phenyl‐3,4‐dihydrochromen‐4(2H)‐one], C18H18O4, displays statistical conformational disorder, with three conformations of the molecule involving three orientations of the phenyl ring and two orientations of the fused heterocyclic ring. The conformational disorder is correlated with the isomerization equilibrium between the flavanone and chalcone forms. The conformational behaviour has a potential impact on the biological activity of this class of compounds. Moreover, π stacking interactions at van der Waals distances are present between the aromatic rings of chroman‐4‐one groups of symmetry‐related molecules. Apart from these π–π interactions, molecules are linked by strong O—H...O hydrogen bonds between hydroxy and carbonyl groups. 相似文献
20.
Carlos A. Escobar Oscar Donoso‐Tauda Ramiro Araya‐Maturana Andrs Vega 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):o426-o430
The 1,5‐benzodiazepine ring system exhibits a puckered boat‐like conformation for all four title compounds [4‐(2‐hydroxyphenyl)‐2‐phenyl‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C21H18N2O, (I), 2‐(2,3‐dimethoxyphenyl)‐4‐(2‐hydroxyphenyl)‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C23H22N2O3, (II), 2‐(3,4‐dimethoxyphenyl)‐4‐(2‐hydroxyphenyl)‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C23H22N2O3, (III), and 2‐(2,5‐dimethoxyphenyl)‐4‐(2‐hydroxyphenyl)‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C23H22N2O3, (IV)]. The stereochemical correlation of the two C6 aromatic groups with respect to the benzodiazepine ring system is pseudo‐equatorial–equatorial for compounds (I) (the phenyl group), (II) (the 2,3‐dimethoxyphenyl group) and (III) (the 3,4‐dimethoxyphenyl group), while for (IV) (the 2,5‐dimethoxyphenyl group) the system is pseudo‐axial–equatorial. An intramolecular hydrogen bond between the hydroxyl OH group and a benzodiazepine N atom is present for all four compounds and defines a six‐membered ring, whose geometry is constant across the series. Although the molecular structures are similar, the supramolecular packing is different; compounds (I) and (IV) form chains, while (II) forms dimeric units and (III) displays a layered structure. The packing seems to depend on at least two factors: (i) the nature of the atoms defining the hydrogen bond and (ii) the number of intermolecular interactions of the types O—H...O, N—H...O, N—H...π(arene) or C—H...π(arene). 相似文献