scholarly journals Synthesis of N-substituted 3-(2-aryl-2-oxoethyl)-3-hydroxyindolin-2-ones and their conversion to N-substituted (E)-3-(2-aryl-2-oxoethylidene)indolin-2-ones: synthetic sequence, spectroscopic characterization and structures of four 3-hydroxy compounds and five oxoethylidene products

2020 ◽  
Vol 76 (5) ◽  
pp. 433-445
Author(s):  
Diana Becerra ◽  
Juan Castillo ◽  
Braulio Insuasty ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Spectroscopic Characterization ◽  
Crystal Structure Analysis ◽  
Dimensional Structure ◽  
Acidic Conditions ◽  
Synthetic Sequence ◽  
Hydroxy Compounds ◽  
Aryl Methyl ◽  
C Nmr

An operationally simple and time-efficient approach has been developed for the synthesis of racemic N-substituted 3-(2-aryl-2-oxoethyl)-3-hydroxyindolin-2-ones by a piperidine-catalysed aldol reaction between aryl methyl ketones and N-alkylisatins. These aldol products were used successfully as strategic intermediates for the preparation of N-substituted (E)-3-(2-hetaryl-2-oxoethylidene)indolin-2-ones by a stereoselective dehydration reaction under acidic conditions. The products have all been fully characterized by 1H and 13C NMR spectroscopy, by mass spectrometry and, for a representative selection, by crystal structure analysis. In each of (RS)-1-benzyl-3-hydroxy-3-[2-(4-methoxyphenyl)-2-oxoethyl]indolin-2-one, C24H21NO4, (Ic), and (RS)-1-benzyl-3-{2-[4-(dimethylamino)phenyl]-2-oxoethyl}-3-hydroxyindolin-2-one, C25H24N2O3, (Id), inversion-related pairs of molecules are linked by O—H...O hydrogen bonds to form R 2 2(10) rings, which are further linked into chains of rings by a combination of C—H...O and C—H...π(arene) hydrogen bonds in (Ic) and by C—H...π(arene) hydrogen bonds in (Id). The molecules of (RS)-1-benzyl-3-hydroxy-3-[2-oxo-2-(pyridin-4-yl)ethyl]indolin-2-one, C22H18N2O3, (Ie), are linked into a three-dimensional framework structure by a combination of O—H...N, C—H...O and C—H...π(arene) hydrogen bonds. (RS)-3-[2-(Benzo[d][1,3]dioxol-5-yl)-2-oxoethyl]-1-benzyl-3-hydroxyindolin-2-one, C24H19NO5, (If), crystallizes with Z′ = 2 in the space group P\overline{1} and the molecules are linked into complex sheets by a combination of O—H...O, C—H...O and C—H...π(arene) hydrogen bonds. In each of (E)-1-benzyl-3-[2-(4-fluorophenyl)-2-oxoethylidene]indolin-2-one, C23H16FNO2, (IIa), and (E)-1-benzyl-3-[2-oxo-2-(thiophen-2-yl)ethylidene]indolin-2-one, C21H15NO2S, (IIg), the molecules are linked into simple chains by a single C—H...O hydrogen bond, while those of (E)-1-benzyl-3-[2-oxo-2-(pyridin-4-yl)ethylidene]indolin-2-one, C22H16N2O2, (IIe), are linked by three C—H...O hydrogen bonds to form sheets which are further linked into a three-dimensional structure by C—H...π(arene) hydrogen bonds. There are no hydrogen bonds in the structures of either (E)-1-benzyl-3-[2-(4-methoxyphenyl)-2-oxoethylidene]indolin-2-one, C24H19NO3, (IIc), or (E)-1-benzyl-5-chloro-3-[2-(4-chlorophenyl)-2-oxoethylidene]indolin-2-one, C23H15Cl2NO2, (IIh), but the molecules of (IIh) are linked into chains of π-stacked dimers by a combination of C—Cl...π(arene) and aromatic π–π stacking interactions.

A concise and efficient concurrent synthesis of 6,11-dihydrodibenzo[b,e]azepines and 5,6,11,12-tetrahydrodibenzo[b,f]azocines and their conversion to 4-oxo-8,13-dihydro-4H-benzo[5,6]azepino[3,2,1-ij]quinoline-5-carboxylates and N-acetyl-5,6,11,12-tetrahydrodibenzo[b,f]azocines: synthetic sequence, spectroscopic characterization and the structures of two products

2019 ◽  
Vol 75 (6) ◽  
pp. 650-656
Author(s):  
Lina M. Acosta Quintero ◽  
Alirio Palma ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Spectroscopic Characterization ◽  
Boat Conformation ◽  
Framework Structure ◽  
Molar Ratios ◽  
Boat Form ◽  
Synthetic Sequence ◽  
Time Form ◽  
Twist Boat

Reaction of 2-allyl-N-benzyl-4-fluoroaniline or 2-allyl-N-benzyl-4-chloroaniline with 98% sulfuric acid leads to the concurrent formation of halogeno-substituted 11-ethyl-6,11-dihydrodibenzo[b,e]azepines, (II), and halogeno-substituted 11-methyl-5,6,11,12-tetrahydrodibenzo[b,f]azocines, (III), in each case in (II):(III) molar ratios of ca 2:1. Further reaction of (II) leads to ethyl 13-ethyl-2-halogeno-4-oxo-8,13-dihydro-4H-benzo[5,6]azepino[3,2,1-ij]quinoline-5-carboxylate, while acetylation of (III) gives the corresponding N-acetyl derivatives. The dibenzo[b,e]azepine and dibenzo[b,f]azocine ring systems are of importance in forming the core of a variety of bioactive compounds. In ethyl 13-ethyl-2-fluoro-4-oxo-8,13-dihydro-4H-benzo[5,6]azepino[3,2,1-ij]quinoline-5-carboxylate, C22H20FNO3, (IVa), the azepine ring adopts a conformation close to the twist-boat form, and the molecules are linked into a three-dimensional framework structure by a combination of C—H...O and C—H...π(arene) hydrogen bonds. The azocine ring in 5-acetyl-2-chloro-11-methyl-5,6,11,12-tetrahydrobenzo[b,f]azocine, C18H18ClNO, (Vb), adopts the boat–boat conformation and the molecules are again linked by C—H...O and C—H...π(arene) hydrogen bonds, but this time form a sheet structure.

A concise and versatile route to tetrahydro-1-benzazepines carrying [a]-fused heterocyclic units: synthetic sequence and spectroscopic characterization, and the molecular and supramolecular structures of one intermediate and two products

2019 ◽  
Vol 75 (2) ◽  
pp. 168-177
Author(s):  
Sergio A. Guerrero ◽  
Juan E. Ramírez ◽  
Alirio Palma ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Mass Spectrometry ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Spectroscopic Characterization ◽  
Chair Conformation ◽  
Supramolecular Structures ◽  
Target Product ◽  
Target Compound ◽  
Synthetic Sequence ◽  
C Nmr

A concise, efficient and versatile route from simple starting materials to tricyclic tetrahydro-1-benzazepines carrying [a]-fused heterocyclic units is reported. Thus, the easily accessible methyl 2-[(2-allyl-4-chlorophenyl)amino]acetate, (I), was converted, via (2RS,4SR)-7-chloro-2,3,4,5-tetrahydro-1,4-epoxy-1-benzo[b]azepine-2-carboxylate, (II), to the key intermediate methyl (2RS,4SR)-7-chloro-4-hydroxy-2,3,4,5-tetrahydro-1H-benzo[b]azepine-2-carboxylate, (III). Chloroacetylation of (III) provided the two regioisomers methyl (2RS,4SR)-7-chloro-1-(2-chloroacetyl)-4-hydroxy-2,3,4,5-tetrahydro-1H-benzo[b]azepine-2-carboxylate, (IVa), and methyl (2RS,4SR)-7-chloro-4-(2-chloroacetoxy)-2,3,4,5-tetrahydro-1H-benzo[b]azepine-2-carboxylate, C14H15Cl2NO4, (IVb), as the major and minor products, respectively, and further reaction of (IVa) with aminoethanol gave the tricyclic target compound (4aRS,6SR)-9-chloro-6-hydroxy-3-(2-hydroxyethyl)-2,3,4a,5,6,7-hexahydrobenzo[f]pyrazino[1,2-a]azepine-1,4-dione, C15H17ClN2O4, (V). Reaction of ester (III) with hydrazine hydrate gave the corresponding carbohydrazide (VI), which, with trimethoxymethane, gave a second tricyclic target product, (4aRS,6SR)-9-chloro-6-hydroxy-4a,5,6,7-tetrahydrobenzo[f][1,2,4]triazino[4,5-a]azepin-4(3H)-one, C12H12ClN3O2, (VII). Full spectroscopic characterization (IR, 1H and 13C NMR, and mass spectrometry) is reported for each of compounds (I)–(III), (IVa), (IVb) and (V)–(VII), along with the molecular and supramolecular structures of (IVb), (V) and (VII). In each of (IVb), (V) and (VII), the azepine ring adopts a chair conformation and the six-membered heterocyclic rings in (V) and (VII) adopt approximate boat forms. The molecules in (IVb), (V) and (VII) are linked, in each case, into complex hydrogen-bonded sheets, but these sheets all contain a different range of hydrogen-bond types: N—H...O, C—H...O, C—H...N and C—H...π(arene) in (IVb), multiple C—H...O hydrogen bonds in (V), and N—H...N, O—H...O, C—H...N, C—H...O and C—H...π(arene) in (VII).

The first crystal structure of the peptidase domain of the U32 peptidase family

2015 ◽  
Vol 71 (12) ◽  
pp. 2505-2512 ◽  
Author(s):  
Magdalena Schacherl ◽  
Angelika A. M. Montada ◽  
Elena Brunstein ◽  
Ulrich Baumann
Keyword(s):  
Crystal Structure ◽  
Catalytic Mechanism ◽  
Quaternary Structure ◽  
Catalytic Domain ◽  
Three Dimensional ◽  
Zinc Ion ◽  
Crystal Structure Analysis ◽  
Dimensional Structure ◽  
Sequence Motifs ◽  
Conserved Sequence

The U32 family is a collection of over 2500 annotated peptidases in the MEROPS database with unknown catalytic mechanism. They mainly occur in bacteria and archaea, but a few representatives have also been identified in eukarya. Many of the U32 members have been linked to pathogenicity, such as proteins fromHelicobacterandSalmonella. The first crystal structure analysis of a U32 catalytic domain fromMethanopyrus kandleri(genemk0906) reveals a modified (βα)8TIM-barrel fold with some unique features. The connecting segment between strands β7 and β8 is extended and helix α7 is located on top of the C-terminal end of the barrel body. The protein exhibits a dimeric quaternary structure in which a zinc ion is symmetrically bound by histidine and cysteine side chains from both monomers. These residues reside in conserved sequence motifs. No typical proteolytic motifs are discernible in the three-dimensional structure, and biochemical assays failed to demonstrate proteolytic activity. A tunnel in which an acetate ion is bound is located in the C-terminal part of the β-barrel. Two hydrophobic grooves lead to a tunnel at the C-terminal end of the barrel in which an acetate ion is bound. One of the grooves binds to aStrep-Tag II of another dimer in the crystal lattice. Thus, these grooves may be binding sites for hydrophobic peptides or other ligands.

Influence of Cl/Br substitution on the stereochemical peculiarities of copper(I) π-complexes with the 1-allyl-2-aminopyridinium cation

2003 ◽  
Vol 59 (11) ◽  
pp. m478-m481 ◽  
Author(s):  
Evgeny Goreshnik ◽  
Dieter Schollmeier ◽  
Marian Mys'kiv
Keyword(s):  
Hydrogen Bonds ◽  
Electrochemical Synthesis ◽  
Three Dimensional ◽  
Alternating Current ◽  
Dimensional Structure ◽  
Three Dimensional Structure

By using alternating-current electrochemical synthesis, crystals of the CuI π-complexes bis(1-allyl-2-aminopyridinium) di-μ-chloro-bis[chlorocopper(I)], (C8H11N2)2[Cu2Cl4] or [H2NC5H4NC3H5][CuCl2], and bis(1-allyl-2-aminopyridinium) di-μ-(chloro/bromo)-bis[(chloro/bromo)copper(I)], (C8H11N2)2[Cu2Br2.2Cl1.8] or [H2NC5H4NC3H5][CuBr1.10Cl0.90], have been obtained and structurally investigated. In each of the isostructural (isomorphous) compounds, the distorted tetrahedral Cu environment involves three halide atoms and the C=C bond of the ligand. Both compounds reside on inversion centres, and the dimeric [Cu2 X 4·2H2NC5H4NC3H5] units are bonded into a three-dimensional structure by N—H...X hydrogen bonds. The Br content in the terminal X1 position is much higher than that in the bridged X2 site.

scholarly journals Crystal structure of 3-deoxy-3-nitromethyl-1,2;5,6-di-O-isopropylidene-α-D-allofuranose

2016 ◽  
Vol 72 (3) ◽  
pp. 314-317
Author(s):  
Jevgeņija Lugiņina ◽  
Vitālijs Rjabovs ◽  
Dmitrijs Stepanovs
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Three Dimensional Structure ◽  
Compound C

The title compound, C13H21NO7{systematic name: (3aR,5S,6R,6aR)-5-[(R)-2,2-dimethyl-1,3-dioxolan-4-yl]-2,2-dimethyl-6-(nitromethyl)tetrahydrofuro[2,3-d][1,3]dioxole}, consists of a substituted 2,2-dimethyltetrahydrofuro[2,3-d][1,3]dioxolane skeleton. The furanose ringAadopts aoT4conformation. The fused dioxolane ringBand the substituent dioxolane ringCalso have twisted conformations. There are no strong hydrogen bonds in the crystal structure: only weak C—H...O contacts are present, which link the molecules to form a three-dimensional structure.

scholarly journals {(3S,5R)-5-(2,4-Difluorophenyl)-5-[(1H-1,2,4-triazol-1-yl)methyl]tetrahydrofuran-3-yl}methyl 4-methylbenzenesulfonate

IUCrData ◽  
2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Qing-Shuang Ma ◽  
Xiao-Guang Wang ◽  
Lei Xu ◽  
Sun Bin ◽  
Dao-Hong Xia ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Three Dimensional Structure ◽  
Axis Direction ◽  
Envelope Conformation ◽  
Compound C ◽  
Best Fit

In the title compound, C21H21F2N3O4S, the tetrahydrofuran ring adopts an envelope conformation with the β-C atom positioned at the flap. The triazole, difluorophenyl and tolyl rings of the various substituents on the tetrahydrofuran ring are inclined at 77.88 (12), 83.81 (10) and 81.00 (10)°, respectively, to the best-fit mean plane through the five atoms of the tetrahydrofuran ring. In the crystal, weak C—H...O and C—H...F hydrogen bonds link the molecules into a three-dimensional structure, with molecules stacked along thea-axis direction.

scholarly journals (3R,5S,7R,8R,9S,10S,12S,13R,14S)-10,13-Dimethyl-17-[5-oxo-5-(prop-2-yn-1-yloxy)pentan-2-yl]hexadecahydro-1H-cyclopenta[a]phenanthrene-3,7,12-triyl triacetate

IUCrData ◽  
2017 ◽  
Vol 2 (3) ◽  
Author(s):  
T. Kavitha ◽  
Devaraj Anandkumar ◽  
Perumal Rajakumar ◽  
Srinivasan Bargavi ◽  
Srinivasakannan Lakshmi
Keyword(s):  
Hydrogen Bonds ◽  
Cholic Acid ◽  
Dihedral Angle ◽  
Title Compound ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Terminal Alkyne ◽  
Compound C ◽  
Cyclopentane Ring ◽  
The Mean

In the title compound, C33H48O8, four terminal H atoms of cholic acid are replaced by three acetyl and one terminal alkyne group. All the acetyl residues are twisted with respect to the rings (A, B and C) to which they are attached. The cyclopentane ring D adopts an envelope conformation with the methyl-substituted C atom as the flap. Rings A, B and C have chair conformations. The dihedral angle between the mean planes of rings C and D is 4.70 (11)°. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming a three-dimensional structure.

scholarly journals (E)-N′-[4-(Dimethylamino)benzylidene]propionohydrazide monohydrate

IUCrData ◽  
2016 ◽  
Vol 1 (10) ◽  
Author(s):  
S. Naveen ◽  
Seranthimata Samshuddin ◽  
Manuel Rodrigues ◽  
Dandavathi Arunkumar ◽  
N. K. Lokanath ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Water Molecules ◽  
Crystal Water ◽  
Three Dimensional Structure ◽  
Π Interactions ◽  
Compound C

In the title hydrated hydrazine compound, C12H17N3O·H2O, the C=N bond adopts an E conformation. In the crystal, water molecules bridge the hydrazine molecules, via N—H...O and O—H...O hydrogen bonds, forming sheets parallel to the bc plane. There are C—H...π interactions present within the sheets, and further C—H...π interactions link the sheets to form a three-dimensional structure.

scholarly journals Bis(μ2-4-nitrophenolato)bis(4-nitrophenolato)di-μ3-oxido-octaphenyltetratin chloroform sesquisolvate [+ solvate]: a tetranuclear stannoxane

IUCrData ◽  
2019 ◽  
Vol 4 (8) ◽  
Author(s):  
Patrick Butler
Keyword(s):  
Hydrogen Bonds ◽  
Electron Density ◽  
Three Dimensional ◽  
The Other ◽  
Dimensional Structure ◽  
Coordination Geometry ◽  
Asymmetric Unit ◽  
Acta Cryst ◽  
Complex Molecules ◽  
Three Dimensional Structure

The title tetranuclear stannoxane, [Sn4(C6H5)8(C6H4NO3)4O2]·1.5CHCl3·solvent, crystallized with two independent complex molecules, A and B, in the asymmetric unit together with 1.5 molecules of chloroform. There is also a region of disordered electron density, which was corrected for using the SQUEEZE routine [Spek (2015). Acta Cryst. C71, 9–18]. The oxo-tin core of each complex is in a planar `ladder' arrangement and each Sn atom is fivefold SnO3C2 coordinated, with one tin centre having an almost perfect square-pyramidal coordination geometry, while the other three Sn centres have distorted shapes. In the crystal, the complex molecules are arranged in layers, composed of A or B complexes, lying parallel to the bc plane. The complex molecules are linked by a number of C—H...O hydrogen bonds within the layers and between the layers, forming a supramolecular three-dimensional structure.

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