scholarly journals Formation of 1-(thiazol-2-yl)-4,5-dihydropyrazoles from simple precursors: synthesis, spectroscopic characterization and the structures of an intermediate and two products

2021 ◽  
Vol 77 (10) ◽  
Author(s):  
Ninganayaka Mahesha ◽  
Hemmige S. Yathirajan ◽  
Holalagudu A. Nagma Banu ◽  
Balakrishna Kalluraya ◽  
Ravindranath S. Rathore ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Reaction Pathway ◽  
Pyrazole Ring ◽  
Spectroscopic Characterization ◽  
Methyl Group

Two new 1-(thiazol-2-yl)-4,5-dihydropyrazoles have been synthesized from simple precursors, and characterized both spectroscopically and structurally. In addition, two intermediates in the reaction pathway have been isolated and characterized, one of them structurally. The molecules of the intermediate (E)-1-(4-methoxyphenyl)-3-[4-(prop-2-ynyloxy)phenyl]prop-2-en-1-one, C19H16O3 (I), are linked by a combination of C—H...O and C—H...π(arene) hydrogen bonds to form ribbons. The products (RS)-5-(4-methoxyphenyl)-1-(4-phenythiazol-2-yl)-3-[4-(prop-2-ynyloxy)phenyl]-4,5-dihydro-1H-pyrazole, C28H23N3O2S (II), and (RS)-5-(4-methoxyphenyl)-1-[4-(4-methylphenyl)thiazol-2-yl]-3-[4-(prop-2-ynyloxy)phenyl]-4,5-dihydro-1H-pyrazole, C29H25N3O2S (III), are closely related – differing only by presence or absence of a methyl group at the arylthiazolyl substituent – and crystallize in an isomorphous setting. Both molecules contain an effectively planar dihydro-pyrazole ring, and possess an overall T-shaped structure, which is a characteristic of triaryl-substituted 4,5-dihydro-1-(thiazol-2-yl)pyrazole compounds. The crystal packing is characterized by intermolecular C—H...S and C—H...π (aryl/alkyne) interactions. A combination of two C—H...π(arene) hydrogen bonds links the product molecules into sheets.

scholarly journals 5-(4-Chlorophenoxy)-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde

2014 ◽  
Vol 70 (5) ◽  
pp. o560-o560 ◽  
Author(s):  
N. Vinutha ◽  
S. Madan Kumar ◽  
S. Shobhitha ◽  
B. Kalluraya ◽  
N. K. Lokanath ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Crystal Packing ◽  
Pyrazole Ring ◽  
Π Interactions ◽  
Compound C

In the title compound, C17H13ClN2O2, the phenyl and chlorobenzene rings are inclined to the central pyrazole ring at 40.84 (9) and 65.30 (9)°, respectively. In the crystal, pairs of C—H...π interactions link the molecules into inversion dimers and C—H...O hydrogen bonds link these dimers into columns extended in [010]. The crystal packing exhibits short intermolecular O...Cl contacts of 3.0913 (16) Å.

scholarly journals Methyl (E)-2-({2-[(E)-(hydroxyimino)methyl]phenoxy}methyl)-3-(4-methylphenyl)acrylate

2012 ◽  
Vol 68 (6) ◽  
pp. o1617-o1617
Author(s):  
G. Ganesh ◽  
J. Srinivasan ◽  
E. Govindan ◽  
M. Bakthadoss ◽  
A. SubbiahPandi
Keyword(s):  
Double Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Crystal Packing ◽  
Aromatic Rings ◽  
Methyl Group ◽  
Compound C ◽  
Benzene Rings ◽  
The Mean ◽  
Centrosymmetric Dimers

In the title compound, C19H19NO4, the dihedral angle between the mean planes through the benzene rings is 82.18 (7)°. The C=N double bond is trans-configured. The molecules are linked into centrosymmetric dimers via pairs of O—H...N hydrogen bonds with the motif R 2 2(6). The crystal packing also features C—H...O interactions. The methyl group attached to one of the aromatic rings is disordered over two almost equally occupied positions [occpancy ratio = 0.51 (4):0.49 (4)].

scholarly journals 4-tert-Butylpyridinium chloride–4,4′-(propane-2,2-diyl)bis(2,6-dimethylphenol)–toluene (2/2/1)

2014 ◽  
Vol 70 (4) ◽  
pp. o413-o414
Author(s):  
Alastair J. Nielson ◽  
Joyce M. Waters
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Packing ◽  
Solvent Molecule ◽  
Site Occupancy ◽  
Chloride Ions ◽  
Methyl Group ◽  
Occupancy Factor ◽  
Site Occupancy Factor ◽  
A Site

In the title solvated salt, C9H14N+·Cl−·C19H24O2·0.5C7H7, two molecules of 4,4′-(propane-2,2-diyl)bis(2,6-dimethylphenol) are linkedviaO—H...Cl hydrogen bonds to two chloride ions, each of which is also engaged in N—H...Cl hydrogen bonding to a 4-tert-butylpyridinium cation, giving a cyclic hydrogen-bonded entity centred at 1/2, 1/2, 1/2. The toluene solvent molecule resides in the lattice and resides on an inversion centre; the disorder of the methyl group requires it to have a site-occupancy factor of 0.5. No crystal packing channels are observed.

Structural insights into methyl- or methoxy-substituted 1-(α-aminobenzyl)-2-naphthol structures: the role of C—H...π interactions

2019 ◽  
Vol 75 (2) ◽  
pp. 189-195 ◽  
Author(s):  
Maria Annunziata M. Capozzi ◽  
Giancarlo Terraneo ◽  
Cosimo Cardellicchio
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Methoxy Group ◽  
Crystal Packing ◽  
Molecular Surface ◽  
Methyl Group ◽  
Π Interactions ◽  
Substituted 1 ◽  
Structural Insights

Aminobenzylnaphthols are a class of compounds containing a large aromatic molecular surface which makes them suitable candidates to study the role of C—H...π interactions. We have investigated the effect of methyl or methoxy substituents on the assembling of aromatic units by preparing and determining the crystal structures of (S,S)-1-{(4-methylphenyl)[(1-phenylethyl)amino]methyl}naphthalen-2-ol, C26H25NO, and (S,S)-1-{(4-methoxyphenyl)[(1-phenylethyl)amino]methyl}naphthalen-2-ol, C26H25NO2. The methyl group influenced the overall crystal packing even if the H atoms of the methyl group did not participate directly either in hydrogen bonding or C—H...π interactions. The introduction of the methoxy moiety caused the formation of new hydrogen bonds, in which the O atom of the methoxy group was directly involved. Moreover, the methoxy group promoted the formation of an interesting C—H...π interaction which altered the orientation of an aromatic unit.

N-(5-Chloro-3-methyl-1-phenylpyrazol-4-ylcarbonyl)-N′-(4-methylphenyl)thiourea

2007 ◽  
Vol 63 (11) ◽  
pp. o4287-o4287 ◽  
Author(s):  
Hai-Tang Du ◽  
Ming Lu ◽  
Wei-Yi Zhou ◽  
Li-Li Sun
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Molecular Conformation ◽  
Crystal Packing ◽  
Pyrazole Ring ◽  
Dihedral Angles ◽  
Compound C

The crystal structure of the title compound, C19H17ClN4OS, has been determined in order to elucidate the molecular conformation. The pyrazole ring makes dihedral angles of 74.3 (3)° and 2.9 (3)° with the phenyl and tolyl rings, respectively; these two six-membered rings are twisted by 71.6 (3)° with respect to each other. The crystal packing of the title compound is stabilized by intramolcular N—H...O and intermolcular N—H...S hydrogen bonds.

scholarly journals 5-(4-Fluorophenyl)-3-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-4,5-dihydro-1H-pyrazole-1-carbothioamide

2012 ◽  
Vol 68 (6) ◽  
pp. o1954-o1955
Author(s):  
Bakr F. Abdel-Wahab ◽  
Ehab Abdel-Latif ◽  
Seik Weng Ng ◽  
Edward R. T. Tiekink
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Torsion Angle ◽  
Crystal Packing ◽  
Pyrazole Ring ◽  
Ring Form ◽  
Compound C ◽  
Thiourea Group ◽  
Supramolecular Chains

In the title compound, C20H19FN6S, the pyrazole ring has an envelope conformation, with the methine C atom being the flap atom. The dihedral angle between the least-squares plane through the pyrazole and triazole rings is 7.59 (9)°, and the triazole and attached benzene ring form a dihedral angle of 74.79 (9)°. The thiourea group is coplanar with the pyrazole ring [N—N—C—S torsion angle = −179.93 (11)°], which enables the formation of an intramolecular N—H...N hydrogen bond. In the crystal, inversion-related molecules associate via N—H...S hydrogen bonds and eight-membered {...HNCS}2 synthons feature in the crystal packing. These synthons are connected into supramolecular chains along the a axis via N—H...F hydrogen bonds, and the chains are consolidated into layers in the ab plane via C—H...S and C—H...F contacts.

scholarly journals (Z)-1-(2-Chlorophenyl)-3-methyl-4-[2-(4-nitrophenyl)hydrazin-1-ylidene]-1H-pyrazol-5(4H)-one

2012 ◽  
Vol 68 (8) ◽  
pp. o2351-o2352 ◽  
Author(s):  
Carlos Bustos ◽  
Andrés Escobar-Fuentealba ◽  
Luis Alvarez-Thon ◽  
Rodrigo Faundez-Gutierrez ◽  
Maria Teresa Garland
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
Crystal Packing ◽  
Pyrazole Ring ◽  
Dihedral Angles ◽  
Stacking Interactions ◽  
Asymmetric Unit ◽  
Compound C ◽  
Π Stacking ◽  
Independent Molecules

There are two independent molecules,AandB, in the asymmetric unit of the title compound, C16H12ClN5O3. The relative orientations of the chlorophenyl ring with respect to the pyrazole ring in the two crystallographically independent molecules are different, and their corresponding dihedral angles are −53.3 (2) and 114.09 (18)° in moleculesAandB, respectively. There are two strong intramolecular N—H...O hydrogen bonds, and two weak intramolecular C—H...O and C—H...Cl hydrogen bonds. The crystal packing is constructed by weak C—H...O and N—H...O interactions, and two π–π stacking interactions [centroid–centroid distances = 3.7894 (9) and 3.5719 (10) Å], forming a molecular ladder along theaaxis.

scholarly journals 4-[5-Amino-4-(4-fluorophenyl)-3-(pyridin-4-yl)-1H-pyrazol-1-yl]benzonitrile

2012 ◽  
Vol 68 (4) ◽  
pp. o935-o935 ◽  
Author(s):  
Bassam Abu Thaher ◽  
Pierre Koch ◽  
Dieter Schollmeyer ◽  
Stefan Laufer
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Crystal Packing ◽  
Pyrazole Ring ◽  
Dihedral Angles ◽  
Two Dimensional ◽  
Compound C ◽  
Dimensional Network

In the crystal structure of the title compound, C21H14FN5, the pyrazole ring forms dihedral angles of 38.0 (1), 40.0 (1) and 28.5 (1)° with the directly attached 4-fluorophenyl, pyridine and benzonitrile rings, respectively. The crystal packing is characterized by N—H...N hydrogen bonds, which result in a two-dimensional network parallel to theac-plane.

scholarly journals 3-(Adamantan-1-yl)-4-benzyl-1H-1,2,4-triazole-5(4H)-thione

2014 ◽  
Vol 70 (7) ◽  
pp. o766-o767 ◽  
Author(s):  
Fatmah A. M. Al-Omary ◽  
Hazem A. Ghabbour ◽  
Ali A. El-Emam ◽  
C. S. Chidan Kumar ◽  
Hoong-Kun Fun
Keyword(s):  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Crystal Packing ◽  
Triazole Ring ◽  
Axis Direction ◽  
Π Interactions ◽  
Compound C ◽  
Supramolecular Chains

The title compound, C19H23N3S, is a functionalized triazoline-3-thione derivative. The benzyl ring is almost normal to the planar 1,2,4-triazole ring (r.m.s. deviation = 0.007 Å) with a dihedral angle of 86.90 (7)°. In the crystal, molecules are linked by pairs of N—H...S hydrogen bonds, forming inversion dimers that encloseR22(8) loops. The crystal packing is further stabilized by weak C—H...π interactions that link adjacent dimeric units into supramolecular chains extending along thea-axis direction.

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