.beta.-Adrenoceptor studies. 5. Proton NMR and IR spectroscopic analysis of the conformation of the hydrohalide salts of .beta.-adrenoceptor-blocking aryloxypropanolamines. Evidence for a seven-membered ring structure with participation of two hydrogen bonds

1979 ◽  
Vol 22 (4) ◽  
pp. 441-449 ◽  
Author(s):  
Johan Zaagsma
Keyword(s):  
Hydrogen Bonds ◽  
Spectroscopic Analysis ◽  
Proton Nmr ◽  
Ring Structure ◽  
Membered Ring ◽  
Beta Adrenoceptor ◽  
Ir Spectroscopic

Diastereoselective formation of 18-membered ring BINOL-hydrogen phosphonate dimers - Quasi-covalent hydrogen bonds?

2007 ◽  
Vol 85 (7-8) ◽  
pp. 466-474 ◽  
Author(s):  
Hossein A Dabbagh ◽  
Nader Noroozi-Pesyan ◽  
Ali R Najafi-Chermahini ◽  
Brian O Patrick ◽  
Brian R James
Keyword(s):  
Hydrogen Bonds ◽  
Computational Analysis ◽  
Ring Structure ◽  
Membered Ring ◽  
Hydrogen Atoms ◽  
Constrained Geometry ◽  
Decomposition Point ◽  
Point Data ◽  
Hydrolysis Of ◽  
Hydroxyl Hydrogen

Diastereoselective syntheses of the unusual dimers, 4-heptyl-2-(2′-hydroxy-binaphthyl)hydrogen phosphonate (5) and the cyclohexyl analogue (7), are achieved by hydrolysis of 4-(3,5-dioxa-4-phosphacyclohepta[2,1-α;3,4-α′]-dinaphthalene-4-yloxy)heptane (4) and the cyclohexane analogue (6), respectively. Two out of eight possible pairs of monomers units are involved in the stereoselective formation of the dimer 5a of configuration BINOLR-PS:BINOLR-PS; this is determined by X-ray crystallographic data, which reveal a centrosymmetric, 18-membered ring structure with Ci symmetry, consisting of two monomers strongly hydrogen-bonded between the oxygen of P=O units and hydroxyl hydrogen atoms. Mass spectrometric, melting point, and thermal decomposition point data, as well as NMR data, support the presence of strong, quasi-covalent hydrogen bonds. Computational analysis suggests that the diastereoselectivity is controlled by molecularly constrained geometry of the monomer. Compound 7, although not characterized crystallographically, appears to be analogous to 5.Key words: 18-membered ring, phosphonate dimer, diastereoselectivity, hydrogen-bonds, computational analysis.

Understanding the microcrystal tests of three related phenethylamines: theortho-metallated (±)-amphetamine formed with gold(III) chloride, and the tetrachloridoaurate(III) salts of (+)-methamphetamine and (±)-ephedrine

2013 ◽  
Vol 69 (4) ◽  
pp. 388-393 ◽  
Author(s):  
Matthew R. Wood ◽  
Roger A. Lalancette
Keyword(s):  
Drug Use ◽  
Illicit Drug ◽  
Illicit Drug Use ◽  
Ring Structure ◽  
Membered Ring ◽  
Asymmetric Unit ◽  
Organic Components ◽  
Bidentate Complex

Theortho-metallation product of the reaction of (±)-amphetamine with gold(III) chloride, [D,L-2-(2-aminopropyl)phenyl-κ2N,C1]dichloridogold(III), [Au(C9H12N)Cl2], and the two salts resulting from crystallization of (+)-methamphetamine with gold(III) chloride, D-methyl(1-phenylpropan-2-yl)azanium tetrachloridoaurate(III), (C10H16N)[AuCl4], and of (±)-ephedrine with gold(III) chloride, D,L-(1-hydroxy-1-phenylpropan-2-yl)(methyl)azanium tetrachloridoaurate(III), (C10H16NO)[AuCl4], have different structures. The first makes a bidentate complex directly with a dichloridogold(III) group, forming a six-membered ring structure; the second and third each form a salt with [AuCl4]−(each has two formula units in the asymmetric unit). The organic components are all members of the same class of stimulants that are prevalent in illicit drug use. These structures are important contributions to the understanding of the microcrystal tests for these drugs that have been employed for well over 100 years.

scholarly journals 14,15-Didehydrohellebrigenin

2012 ◽  
Vol 68 (6) ◽  
pp. o1614-o1615
Author(s):  
Tong Yu ◽  
Hai-Yan Tian ◽  
Xiao-Feng Yuan ◽  
Shu-Zhi Hu ◽  
Ren-Wang Jiang
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Lactone Ring ◽  
Three Dimensional ◽  
Membered Ring ◽  
Envelope Conformation ◽  
Compound C ◽  
Dimensional Network ◽  
Hydroxy Groups

The title compound, C24H30O5, is the didehydro product of the steroid hellebrigenin (systematic name: 3β,5,14-trihydroxy-19-oxo-5β-bufa-20,22-dienolide). It consists of three cyclohexane rings (A, B and C), a five-membered ring (D) and a six-membered lactone ring (E). The stereochemistry of the ring junctions are A/B cis, B/C trans and C/D cis. Cyclohexane rings A, B and C have normal chair conformations. The five-membered ring D with the C=C bond adopts an envelope conformation. Lactone ring E is essentially planar with a mean derivation of 0.006 (4) Å and is β-oriented at the C atom of ring D to which it is attached. There is an O—H...O hydrogen bond in the molecule involving the hydroxy groups. In the crystal, O—H...O hydrogen bonds link the molecules into chains propagating along [010]. The chains are linked by C—H...O contacts into a three-dimensional network.

scholarly journals Crystal structure of creatininium 5-(2,4-dinitrophenyl)-1,3-dimethylbarbiturate monohydrate: a potential anticonvulsant agent

2016 ◽  
Vol 72 (5) ◽  
pp. 620-623
Author(s):  
Ponnusamy Poornima Devi ◽  
Doraisamyraja Kalaivani
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Three Dimensional ◽  
Pyrimidine Ring ◽  
Membered Ring ◽  
Anticonvulsant Agent ◽  
The Mean ◽  
Anions And Cations ◽  
Molecular Salt

In the anion of the title hydrated molecular salt, C4H8N3O+·C12H9N4O7−·H2O [systematic name: 2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium 5-(2,4-dinitrophenyl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate monohydrate], the 2,4-dinitrophenyl ring is inclined to the mean plane of the pyrimidine ring [r.m.s. deviation = 0.37 Å] by 43.24 (8)°. The five-membered ring of the creatininium cation (2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium) is essentially planar with an r.m.s. deviation of 0.015 Å. In the crystal, the anions and cations are linkedviaN—H...O hydrogen bonds, forming sheets parallel to theabplane. The sheets are linkedviaO—H...O hydrogen bonds involving the water molecule, forming a three-dimensional framework. Within the framework, there are C—H...O hydrogen bonds present. The title molecular salt displays anticonvulsant and hypnotic activities.

Synthesis, crystal structure and molecular conformation of (±)-1-oxoferruginol and (±)-shonanol

2004 ◽  
Vol 219 (10) ◽  
Author(s):  
Swastik Mondal ◽  
Monika Mukherjee ◽  
Arnab Roy ◽  
Debabrata Mukherjee
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Diffraction Data ◽  
Molecular Conformation ◽  
Membered Ring ◽  
Methyl Groups ◽  
Single Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Structures

Abstract(±)-1-oxoferruginol and (±)-shonanol, two potential intermediates in the synthesis of tricyclic diterpenoid ferruginol, have been prepared and crystal structures of the compounds have been investigated using single-crystal X-ray diffraction data. The methyl groups of the isopropyl moiety in (±)-shonanol are disordered over two positions with occupation factors 0.65(1) and 0.35(1), respectively. Although the chemical structures of two compounds are very similar, a C—C single bond in the terminal six-membered ring of (±)-1-oxoferruginol is replaced by a C=C bond in (±)-shonanol, the quantitative isostructurality index calculations indicate that the structures are not isostructural. Intermolecular O—H…O hydrogen bonds between pairs of molecules in the compounds related by center of inversion lead to characteristic dimers forming R

scholarly journals Chemometric and IR spectroscopic analysis of adhesive tapes

2013 ◽  
Vol 17 (3) ◽  
pp. 339-344 ◽  
Author(s):  
A. M. Tsikin ◽  
Y. B. Monakhova ◽  
S. P. Kurchatkin ◽  
S. P. Mushtakova
Keyword(s):  
Spectroscopic Analysis ◽  
Ir Spectroscopic
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