Crystal structures. vol. 6. the structure of benzene derivatives. part 1: molecules containing one benzene ring

1971 ◽  
Vol 10 (2) ◽  
pp. 317
Author(s):  
W.J.O-T.
Keyword(s):  
Crystal Structures ◽  
Benzene Ring ◽  
Benzene Derivatives

Synthesis, characterization and crystal structures of novel fluorinated di(thiazolyl)benzene derivatives

2019 ◽  
Vol 6 (6) ◽  
pp. 780-790 ◽  
Author(s):  
Maciej Barłóg ◽  
Ihor Kulai ◽  
Xiaozhou Ji ◽  
Nattamai Bhuvanesh ◽  
Somnath Dey ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Benzene Derivatives ◽  
Stille Coupling ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microwave Assisted

A series of 11 novel fluorinated and non-fluorinated di(thiazolyl)benzenes have been synthesized via microwave assisted Stille coupling and characterized using X-ray crystallography.

scholarly journals Crystal Structures of Four Novel Thiophene/Phenyl-piperidine Hybrid Chalcones

2014 ◽  
Vol 70 (a1) ◽  
pp. C1020-C1020
Author(s):  
Masood Parvez ◽  
Muhammad Bakhtiar ◽  
Muhammad Baqir ◽  
Muhammad Zia-ur-Rehman
Keyword(s):  
Hydrogen Bonding ◽  
Pharmaceutical Industry ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Benzene Ring ◽  
Drug Targets ◽  
Important Class ◽  
Hydrogen Bonding Interactions ◽  
Benzene Rings ◽  
Type C

Chalcones constitute an important class of bioactive drug targets in the pharmaceutical industry that includes anti-ulcerative drug sofalcone. In continuation of our work, the crystal structures of four closely related 1-phenyl-piperidine based chalcones will be presented. I: C19 H21NOS, MW = 311.43, T = 173(2) K, λ = 0.71073 Å, Orthorhombic, P b c a, a = 10.1045(4), b = 10.5358(4), c = 30.6337(12) Å, V = 3261.2(2) Å3, Z = 8, Dc = 1.269 Mg/m3, F (000) = 1328, R [I>2σ(I)] = 0.059. II: C18H19NOS, MW = 297.40, T = 173(2) K, λ = 1.54178 Å, Orthorhombic, P b c a, a = 8.9236(2), b = 11.0227(2), c = 30.8168(6) Å, V = 3031.21(11) Å3 Z = 8, Dc = 1.303 Mg/m3, F (000) = 1264, R [I>2σ(I)] = 0.035. III: C18H19NOS, MW = 297.40, T = 173(2) K, λ = 1.54178 Å, Orthorhombic, P b c a, a = 8.82990(10), b = 11.0061(2), c = 31.2106(5) Å, V = 3033.13(8) Å3, Z = 8, Dc = 1.303 Mg/m3, F (000) = 1264, R [I>2σ(I)] = 0.048. IV: C18H18ClNOS, MW = 331.84, T = 173(2) K, λ = 0.71073 Å, Monoclinic, P 21/c, a = 14.1037(4), b = 11.3153(3), c = 10.1290(2) Å, β = 101.1367(14)0, V = 1586.02(7) Å3, Z = 4, Dc = 1.390 Mg/m3, F (000) = 696, R [I>2σ(I)] = 0.038. The crystals of I, II and III are isomorphous. In all structures, the piperidine rings are in chair conformations, thiophene rings are essentially planar and the C=C bonds in the prop-2-en-1-one fragment adopt E-conformation. All crystal structures are devoid of any classical hydrogen bonds. However, non-classical hydrogen bonding interactions of the type C---H...O in compounds II, III and IV link the molecules into chains extended along the b-axis. Moreover, C---H...Cg interactions involving thiophene rings in I and III and benzene ring in IV and π...π interactions between benzene rings lying about inversion centers are present in II and III.

scholarly journals Crystal structures of ethyl 6-(4-methylphenyl)-4-oxo-4H-chromene-2-carboxylate and ethyl 6-(4-fluorophenyl)-4-oxo-4H-chromene-2-carboxylate

2016 ◽  
Vol 72 (1) ◽  
pp. 8-13 ◽  
Author(s):  
Ligia R. Gomes ◽  
John Nicolson Low ◽  
Carlos Fernandes ◽  
Alexandra Gaspar ◽  
Fernanda Borges
Keyword(s):  
Crystal Structures ◽  
Benzene Ring ◽  
Phenyl Group ◽  
Dihedral Angles ◽  
Stacking Interactions ◽  
Carbonyl Groups ◽  
Π Interactions ◽  
Ester Moiety ◽  
The Mean ◽  
A Chain

The crystal structures of two chromone derivatives,viz.ethyl 6-(4-methylphenyl)-4-oxo-4H-chromene-2-carboxylate, C19H16O4, (1), and ethyl 6-(4-fluorophenyl)-4-oxo-4H-chromene-2-carboxylate C18H13FO4, (2), have been determined: (1) crystallizes with two molecules in the asymmetric unit. A comparison of the dihedral angles beween the mean planes of the central chromone core with those of the substituents, an ethyl ester moiety at the 2-position and apara-substituted phenyl ring at the 6-position shows that each molecule differs significantly from the others, even the two independent molecules (aandb) of (1). In all three molecules, the carbonyl groups of the chromone and the carboxylate aretrans-related. The supramolecular structure of (1) involves only weak C—H...π interactions between H atoms of the substituent phenyl group and the phenyl group, which link molecules into a chain of alternating moleculesaandb, and weak π–π stacking interactions between the chromone units. The packing in (2) involves C—H...O interactions, which form a network of two intersecting ladders involving the carbonyl atom of the carboxylate group as the acceptor for H atoms at the 7-position of the chromone ring and from anortho-H atom of the exocyclic benzene ring. The carbonyl atom of the chromone acts as an acceptor from ameta-H atom of the exocyclic benzene ring. π–π interactions stack the molecules by unit translation along theaaxis.

scholarly journals Crystal structures of 2-[(4,6-diaminopyrimidin-2-yl)sulfanyl]-N-(naphthalen-1-yl)acetamide and 2-[(4,6-diaminopyrimidin-2-yl)sulfanyl]-N-(4-fluorophenyl)acetamide

2017 ◽  
Vol 73 (2) ◽  
pp. 306-309 ◽  
Author(s):  
S. Subasri ◽  
Timiri Ajay Kumar ◽  
Barij Nayan Sinha ◽  
Venkatesan Jayaprakash ◽  
Vijayan Viswanathan ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Benzene Ring ◽  
Three Dimensional ◽  
Pyrimidine Ring ◽  
Ring System ◽  
Naphthalene Ring

The title compounds, C16H15N5OS, (I), and C12H12FN5OS, (II), are [(diaminopyrimidine)sulfanyl]acetamide derivatives. In (I), the pyrimidine ring is inclined to the naphthalene ring system by 55.5 (1)°, while in (II), the pyrimidine ring is inclined to the benzene ring by 58.93 (8)°. In (II), there is an intramolecular N—H...N hydrogen bond and a short C—H...O contact. In the crystals of (I) and (II), molecules are linked by pairs of N—H...N hydrogen bonds, forming inversion dimers withR22(8) ring motifs. In the crystal of (I), the dimers are linked by bifurcated N—H...(O,O) and C—H...O hydrogen bonds, forming layers parallel to (100). In the crystal of (II), the dimers are linked by N—H...O hydrogen bonds, also forming layers parallel to (100). The layers are linked by C—H...F hydrogen bonds, forming a three-dimensional architecture.

scholarly journals Ring Contraction Reactions of a Non-Benzenoid Aromatic Cation and a Neutral Homoaromatic System into Benzene Derivatives

2021 ◽  
Author(s):  
Demelza Lyons ◽  
An Huy Dinh ◽  
Nhan Nu Hong Ton ◽  
Reece Crocker ◽  
Binh Khanh Mai ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Benzene Ring ◽  
Benzene Derivatives ◽  
Ring Contraction ◽  
Chemistry Research ◽  
Synthetic Utility ◽  
Aromatic Ions ◽  
Benzyl Halides ◽  
Tropylium Salts ◽  
Ring Contraction Reaction

Aromaticity is one of the most intriguing concepts in organic chemistry. Simple and extended benzenoid aromatic systems have been very well established in undergraduate textbooks, and there are also mentions of non-benzenoid aromatic structures such as cyclopropenium, cyclopentadienide and cycloheptatrienylium (tropylium) ions. However, the structural relationship and the comparison of stabilization energy of such aromatic ions to benzene ring have been rarely studied and remained an underexplored area of advanced organic chemistry research. To contribute some insights into this topic, we focused on the chemical transformation, namely a ring contraction reaction, of the tropylium ion to benzene ring in this work. With an approach combining computational studies with experimental reactions, we also aim to turn this transformation into a synthetically useful tool. Indeed, this work led to the development of a new synthetic protocol, which involved an oxidative ring-contraction of tropylium ion, to formally introduce the phenyl ring onto a range of organic structures. Furthermore, the homoaromatic cycloheptatrienyl precursors of tropylium salts used in these reactions can also be rearranged to valuable benzhydryl or benzyl halides, enriching the synthetic utility of this ring-contraction protocol.

The Responses of Onion and Lily Mitosis to Coumarin and Parasorbic Acid

1947 ◽  
Vol 23 (3-4) ◽  
pp. 292-297
Author(s):  
IVOR CORNMAN
Keyword(s):  
Aqueous Solution ◽  
Benzene Ring ◽  
Lactone Ring ◽  
Saturated Solution ◽  
Saturated Aqueous Solution ◽  
Benzene Derivatives ◽  
Binucleate Cells

1. In Allium and Lilium roots, saturated aqueous solution of coumarin produced a disruption of the metaphase typical of many benzene derivatives, viz. suppression of the spindle, splitting and shortening of the chromosomes, with retarded division of the centromere. The resultant polyploid nuclei and binucleate cells resumed division when the roots were returned to water. 2. Saturated solution of parasorbic acid slowed Allium mitosis, but caused no abnormalities. 3. Both coumarin and parasorbic acid eventually prevented the inception of mitosis, and this suppression of prophases persisted for several hours after removal of the agent. 4. The results are in agreement with prior evidence that in some configurations the benzene ring disrupts mitosis whereas the lactone ring inhibits growth.

Carbon-13 Substituent-Induced Chemical Shifts: Monosubstituted Benzene Derivatives

1992 ◽  
Vol 57 (3) ◽  
pp. 497-507 ◽  
Author(s):  
Otto Exner ◽  
Miloš Buděšínský
Keyword(s):  
Benzene Ring ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
The Other ◽  
Correlation Equations ◽  
Benzene Derivatives ◽  
Complex Mechanism ◽  
Monosubstituted Benzene ◽  
Resonance Effects ◽  
Other Hand

Carbon-13 NMR spectra of twelve monosubstituted benzene derivatives were measured in deuterochloroform. Together with the literature data a set of 35 systematically chosen substituents was obtained on which some thirty correlation equations were tested. As anticipated only substituent chemical shifts (SCS) in the position 4 are controlled by inductive and resonance effects, and can be correlated by dual substituent parameters (DSP). For the other positions DSP were not successful and more sophisticated equations are not much telling. On the other hand, the direct relations between two series of SCS are usually more precise and simple to understand. It is concluded that SCS in benzene ring need not be controlled by too complex mechanism but simply by different factors than by inductive and resonance effects.

Photochemistry of halogenated benzene derivatives. Part VI. Photoreactions of tetra-and pentachlorophenols in water–acetonitrile mixtures

1985 ◽  
Vol 63 (2) ◽  
pp. 469-475 ◽  
Author(s):  
Ghulam Ghaus Choudhry ◽  
Frans W. M. van der Wielen ◽  
G. R. Barrie Webster ◽  
Otto Hutzinger
Keyword(s):  
Benzene Ring ◽  
Reductive Dechlorination ◽  
Benzene Derivatives ◽  
Aqueous Acetonitrile ◽  
Acetonitrile Solutions

Laboratory photochemical studies of aqueous acetonitrile solutions of some polychlorinated phenols (PCPs) such as 2,3,4,5-tetrachlorophenol (2,3,4,5-Cl4-Pn) (1), 2,3,4,6-Cl4-Pn (2), 2,3,5,6-Cl4-Pn (3), and pentachlorophenol (Cl5-Pn) (4) at λ > 285 nm have been carried out for 6 and 24 h exposure times. All the investigated PCPs underwent reductive dechlorination. This process was dependent not only upon the position of OH group but also upon the relative positions of the Cl substituents on the benzene ring. The Cl4-Pn 2 (and 3) and Cl5-Pn (4) also yielded photoproducts of molecular formulae C8H4Cl3NO (M+• = 235) and C8H3Cl4NO (M+• = 269), respectively. Furthermore, phenol 3 is unique amongst the investigated PCPs; in addition to the above mentioned photoproducts, it yielded hexa-, hepta-, and octachlorodihydroxybiphenyl(s) as well as heptachlorohydroxydiphenyl ether.

Structural characteristics of dibromoborylated benzene derivatives

2012 ◽  
Vol 68 (6) ◽  
pp. o226-o230 ◽  
Author(s):  
Sebastian Popp ◽  
Kai Ruth ◽  
Hans-Wolfram Lerner ◽  
Michael Bolte
Keyword(s):  
Crystal Structures ◽  
Aromatic Ring ◽  
Structural Characteristics ◽  
Geometric Parameters ◽  
Mirror Plane ◽  
Methyl Groups ◽  
Benzene Derivatives ◽  
Asymmetric Unit ◽  
Bond Lengths ◽  
Structural Database

The crystal structures of five dibromobenzene derivatives, namely dibromoborylbenzene, C6H5BBr2, (I), 1-dibromoboryl-4-(trimethylsilyl)benzene, C9H13BBr2Si, (II), 4-bromo-1-(dibromoboryl)benzene, C6H4BBr3, (III), dibromo(dimethylamino)(phenyl)borane, C8H12BBr2N, (IV), and dibromo(dimethylsulfanyl)[4-(trimethylsilyl)phenyl]borane, C11H19BBr2SSi, (V), have been determined. Compounds (I)–(IV) crystallize with one molecule in the asymmetric unit, but the molecule of (V) is located on a crystallographic mirror plane, implying twofold disorder of the central aromatic ring, the S atom and one of the methyl groups bonded to the S atom. In (I), (II) and (III), the B atom is three-coordinated, and in (IV) and (V) it is four-coordinated. The geometric parameters of the –BBr2group in these five structures agree well with those of comparable structures retrieved from the Cambridge Structural Database. The C—B and B—Br bond lengths in the molecules with a three-coordinated B atom are significantly shorter than those in the molecules with a four-coordinated B atom. In the compounds with a three-coordinated B atom, the –BBr2group tends to be coplanar with the aromatic ring to which it is attached.

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