Synthesis and properties of oxytocin analogues modified in the tripeptide side chain

1984 ◽  
Vol 49 (3) ◽  
pp. 642-652 ◽  
Author(s):  
Zdenko Procházka ◽  
Michal Lebl ◽  
Tomislav Barth ◽  
Jan Hlaváček ◽  
Antonín Trka ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Carboxylic Acid ◽  
Biological Activities ◽  
The Other ◽  
Side Chain ◽  
H Nmr ◽  
Fragment Condensation

Two oxytocin analogues were synthesized by fragment condensation (6 + 3) in the presence of dicyclohexylcarbodiimide and 1-hydroxybenzotriazole. In one of the analogues, proline in the position 7 and leucine in the position 8 were substituted by 2-[1-(2-oxo-3-aminopyrrolidinyl)]-4-methylpentanoic acid, in the other proline was replaced by 1-aminocyclopropane-1-carboxylic acid. Biological activities of the first analogue were strongly reduced and dissociation of the uterotonic and galoctogogic activities was observed with both the analogues. The structure of 2-(3-tert-butyloxycarbonylaminopyrrolidin-2-on-1-yl)-4-methylpentanoylglycine and its amide was confirmed by mass and 1 H NMR spectroscopy.

scholarly journals Electron Release and Proton Acceptance Reactions of (dpp-BIAN)Mg(THF)3

2008 ◽  
Vol 63 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Igor L. Fedushkin ◽  
Valentina A. Chudakova ◽  
Markus Hummert ◽  
Herbert Schumann
Keyword(s):  
Nmr Spectroscopy ◽  
Carboxylic Acid ◽  
Ir Spectroscopy ◽  
The Other ◽  
X Ray ◽  
H Nmr ◽  
Trigonal Bipyramidal ◽  
Electron Release ◽  
Coordination Spheres ◽  
Centrosymmetric Dimers

(dpp-BIAN)Mg(THF)3 (1) (dpp-BIAN = 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) and (PhCOO)2 react with splitting of the peroxide bridge and formation of the dimeric magnesium benzoate [(dpp-BIAN)MgOCOPh(THF)]2 (2). The reaction of 1 with PhCOOH yields the dimeric magnesium benzoate [(dpp-BIAN)(H)MgOCOPh(THF)]2 (3), whereas 1 and furanyl-2-carboxylic acid react with liberation of hydrogen and formation of (dpp-BIAN)Mg[OCO(2-C4H3O)]2 Mg(dpp-BIAN)(THF) (4). Compounds 2, 3, and 4 have been characterized by elemental analysis, IR spectroscopy, and X-ray structure analysis, compound 3 also by 1H NMR spectroscopy. The eightmembered metallacycles of the centrosymmetric dimers 2 and 3 are almost completely planar. The two magnesium atoms in 4 show different coordination spheres; one is surrounded by its ligands in a trigonal bipyramidal manner, the other one in a tetrahedral fashion. The Mg···Mg separations in 2, 3 and 4 are 4.236, 4.296, and 4.030 Å, respectively

Gehinderte Ligandbewegungen in Übergangsmetallkomplexen, XXXI [1]. Synthese und Dynamik von Acetyl-carbonyl-η5-cyclopentadienyl-η4-dien-wolfram-Komplexen / Hindered Ligand Movements in Transition Metal Complexes, XXXI [1]. Syntheses and Dynamics of Acetyl-carbonyl-η5-cyclopentadienyl-η4-diene-tungsten Complexes

1986 ◽  
Vol 41 (5) ◽  
pp. 599-605 ◽  
Author(s):  
Cornelius G. Kreiter ◽  
Kurt Nist ◽  
Joachim Kögler
Keyword(s):  
Nmr Spectroscopy ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Conjugated Dienes ◽  
The Other ◽  
Molecular Plane ◽  
H Nmr ◽  
Tungsten Complexes ◽  
Diene Ligands

Tricarbonyl-η5-cyclopentadienyl-methyl-tungsten (1) reacts upon UV irradiation with conjugated dienes, like 1,3-butadiene (2), E-1,3-pentadiene (3), 2-methyl-1,3-butadiene (4), 2,3-dimethyl-1,3- butadiene (5), 1,3-cyclopentadiene (6) and 1,3-cyclohexadiene (7), to give the corresponding, quasisquare- pyramidal [(η5-C5H5)W(CO)(COCH3)(η4-diene)] complexes (8-13). With the unsymmetrically substituted dienes 3 and 4, only one of the possible diastereotopic complexes are obtained. At 200 to 230 K, 8-12 show two isomers, which are distinguished by the orientations (o or u) of the diene with respect to the other ligands. The interconversion of the o- and u-isomers was studied by dynamic 1H NMR spectroscopy and is explained by an intramolecular ±180° rotation of the diene ligands in the molecular plane. The barriers o f activation ⊿G* 300 are between 57.8 and 61.0 ± 1 kJ/mol.

Liquid crystalline vinylcyclopropane derivatives bearing cholesteryl side groups: synthesis, characterization and polymerization

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Valentina Alupei ◽  
Helmut Ritter
Keyword(s):  
Phase Transition ◽  
Nmr Spectroscopy ◽  
Carboxylic Acid ◽  
Ir Spectroscopy ◽  
Radical Polymerization ◽  
Liquid Crystalline ◽  
Optically Active ◽  
H Nmr

AbstractNew optically active 1,1-disubstituted 2-vinylcyclopropanes ,3a, b were synthesized by esterification of the corresponding 1-ethoxycarbonyl-2-vinylcyclopropane- 1-carboxylic acid 2a,b with cholesterol and characterized by 1H NMR and IR spectroscopy. The liquid crystalline properties of the obtained monomers are reported. The effect of the structure of the 2-vinylcyclopropane monomers on the phase transition of the mesogen was investigated. Radical polymerization of the asymmetrically substituted monomers 3a,b in solution and in bulk resulted in liquidcrystalline polymers with 1,5-opened units, as evidenced by 1H NMR spectroscopy.

Steroids with the β-crotonate (2-butenoate) side chain

1986 ◽  
Vol 51 (1) ◽  
pp. 128-140 ◽  
Author(s):  
Ivan Černý ◽  
Vladimír Pouzar ◽  
Pavel Drašar ◽  
František Tureček ◽  
Miroslav Havel
Keyword(s):  
Double Bond ◽  
Nmr Spectroscopy ◽  
Lithium Salt ◽  
Side Chain ◽  
H Nmr ◽  
C Nmr

Ethyl (20E)-3β-methoxymethoxy-24-nor-5,20(22)-choladien-23-oate (Va) and analogous derivatives with 5α,5β and Δ5,14 steroid moiety (Vb,Vc and Vd, respectively) were prepared by Wittig-Horner reaction of the corresponding ketones IIa-IId with diethyl ethoxycarbonylmethylphosphonate. In this case the reaction affords exclusively the (E)-isomers, in contrast with the Peterson reaction with lithium salt of ethyl 2-(trimethylsilyl)acetate which gives a mixture of (E)- and (Z)-isomers at the Δ20(22) double bond. The structure of the products was confirmed by 1H NMR and 13C NMR spectroscopy. The crotonates Va-Vd were further converted into the 3-O-succinyl derivatives VIIIa-VIIId.

Multinuclear magnetic resonance studies of the aqueous products of the complexes cis- and trans-Pt(Ypy)2(NO3)2 where Ypy = pyridine derivative

2002 ◽  
Vol 80 (4) ◽  
pp. 379-387 ◽  
Author(s):  
Fernande D Rochon ◽  
Christian Tessier
Keyword(s):  
Nmr Spectroscopy ◽  
The Other ◽  
Basic Medium ◽  
Pyridine Derivative ◽  
Neutral Medium ◽  
Coupling Constant ◽  
Magnetic Resonance Studies ◽  
H Nmr ◽  
Cis And Trans ◽  
Ortho Substituent

The hydrolyis or the aquation reactions of compounds of the types cis- and trans-Pt(Ypy)2(NO3)2 (Ypy = pyridine derivative) were studied in D2O and characterized by multinuclear (195Pt, 13C, and 1H) NMR spectroscopy. In acidic pD, the product of the cis complexes is cis-[Pt(Ypy)2(D2O)2]2+, whereas in basic medium cis-Pt(Ypy)2(OD)2 is formed. The 195Pt NMR resonances of the products containing ligands with an ortho substituent were observed at lower fields than the other complexes. The average coupling constant (3J(195Pt–1H) and 3J(195Pt–13C)) is 44 Hz for the diaqua species and 42 Hz for the dihydroxo compounds. At neutral pD, several hydrolyzed species were observed, except for the 2-picoline and 2,4-lutidine complexes, which contained only one compound, cis-[Pt(Ypy)2(D2O)(OD)]+. The other hydrolyzed products for the ligands with no ortho substituent were identified as the dihydroxo-bridged dimer, the monohydroxo-bridged dimer, the trimer, and possibly the tetramer. The trans analogues have shown two signals in acidic pD corresponding to the diaqua monomer and the monohydroxo-bridged aqua dimer. Two species (the dihydroxo compound and the monohydroxo-bridged hydroxo dimer) were also observed in basic pD. In neutral medium, a third signal assigned to a longer chain hydroxo-bridged oligomer or polymer was detected.Key words: platinum, pyridine derivative, nitrato, hydrolysis, NMR, aquation.

Stereochemistry of some substituted 2-furyl- and 2-thienyl ethylene derivatives. 1H NMR study

1982 ◽  
Vol 47 (12) ◽  
pp. 3412-3417 ◽  
Author(s):  
Miloslava Dandárová ◽  
Jaroslav Kováč ◽  
Daniel Végh ◽  
Vladimír Žvak
Keyword(s):  
Double Bond ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Side Chain ◽  
H Nmr ◽  
Nmr Study ◽  
Thiophene Derivatives

Stereochemistry of (E)- and (Z)-1-(5-nitro-2-furyl)-2-Y-ethylenes and 1-(5-nitro-2-thienyl)-2-Y-ethylenes (where Y = CH3O, 4-CH3C6H4O, N3 and Br) and of E and Z isomers of methyl 2-methyl-3-(2-furyl)propenoate and methyl 2-methyl-3-(2-thienyl)propenoate was studied by 1H NMR spectroscopy. With 1-(5-nitro-2-furyl)-2-Y-ethylenes, it was found that the preferred conformation of the furyl substituent relative to the side chain double bond is s-trans in the E isomers and s-cis in the Z isomers. The s-cis conformation is prevailing in both isomers of methyl 2-methyl-3-(2-furyl)propenoate. The E and Z isomers of all studied thiophene derivatives exist in the s-trans conformation.

Cycloaddition Reactions of Arylmethylenemalonaldehydes with Olefins

1992 ◽  
Vol 57 (11) ◽  
pp. 2337-2358 ◽  
Author(s):  
Dalimil Dvořák ◽  
David Šaman ◽  
Zdeněk Arnold ◽  
Ivana Císařová ◽  
Václav Petříček
Keyword(s):  
Nmr Spectroscopy ◽  
Carboxylic Acid ◽  
Vinyl Ether ◽  
Aromatic Nucleus ◽  
Ethyl Vinyl Ether ◽  
Cycloaddition Reactions ◽  
Ethyl Vinyl ◽  
X Ray ◽  
H Nmr ◽  
Conformational Equilibria

A series of 2,4-disubstituted 3,4-dihydro-2H-pyran-5-carboxaldehydes II-XIX was prepared by reaction of substituted arylmethylenemalonaldehydes I with 2-methylpropane, 1,1-diphenylethylene, styrene, ethyl vinyl ether, 1,1-dimethoxyethylene and 1,1-bis(methylthio)ethylene. In the case of the reaction with ethyl vinyl ether the dependence of the ratio of the arising cis- and trans- 2-ethoxy-4-aryl-3,4-dihydropyran-5-carboxaldehydes VII-XIV on the substitutent on the aromatic nucleus was studied. Information on the mechanism of this reaction was obtained and conformational equilibria of 2-ethoxy-4-aryl-3,4-dihydropyran-5-carboxaldehydes in solution were studied by 1H NMR spectroscopy. The structure of trans-2-ethoxy-4-(4-chlorophenyl)-3,4-dihydropyran-5-carboxaldehyde (trans-VIII) was confirmed by X-ray analysis of the corresponding carboxylic acid trans-XXII.

scholarly journals Starazo triple switches – synthesis of unsymmetrical 1,3,5-tris(arylazo)benzenes

2020 ◽  
Vol 16 ◽  
pp. 22-31
Author(s):  
Andreas H Heindl ◽  
Hermann A Wegner
Keyword(s):  
Nmr Spectroscopy ◽  
Smart Materials ◽  
Storage Capacity ◽  
Aryl Halides ◽  
Information Storage ◽  
The Other ◽  
Coupling Reactions ◽  
Efficient Synthesis ◽  
H Nmr ◽  
New Class

Multistate switches allow to drastically increase the information storage capacity and complexity of smart materials. In this context, unsymmetrical 1,3,5-tris(arylazo)benzenes – ‘starazos’ – which merge three photoswitches on one benzene ring, were successfully prepared. Two different synthetic strategies, one based on Baeyer–Mills reactions and the other based on Pd-catalyzed coupling reactions of arylhydrazides and aryl halides, followed by oxidation, were investigated. The Pd-catalyzed route efficiently led to the target compounds, unsymmetrical tris(arylazo)benzenes. These triple switches were preliminarily characterized in terms of their isomerization behavior using UV–vis and 1H NMR spectroscopy. The efficient synthesis of this new class of unsymmetrical tris(arylazo)benzenes opened new avenues to novel multistate switching materials.

scholarly journals Synthesis of multivalent carbohydrate mimetics with aminopolyol end groups and their evaluation as L-selectin inhibitors

2015 ◽  
Vol 11 ◽  
pp. 638-646 ◽  
Author(s):  
Joana Salta ◽  
Jens Dernedde ◽  
Hans-Ulrich Reissig
Keyword(s):  
Nmr Spectroscopy ◽  
Carboxylic Acid ◽  
Amide Bonds ◽  
H Nmr ◽  
End Groups ◽  
Full Conversion ◽  
Purification Protocol ◽  
Micromolar Range

In this article a series of divalent and trivalent carbohydrate mimetics on the basis of an enantiopure aminopyran and of serinol is described. These aminopolyols are connected by amide bonds to carboxylic acid derived spacer units either by Schotten–Baumann acylation or by coupling employing HATU as reagent. The O-sulfation employing the SO3·DMF complex was optimized. It was crucial to follow this process by 700 MHz 1H NMR spectroscopy to ensure full conversion and to use a refined neutralization and purification protocol. Many of the compounds could not be tested as L-selectin inhibitor by SPR due to their insolubility in water, nevertheless, a divalent and a trivalent amide showed surprisingly good activities with IC50 values in the low micromolar range.

Mixed behavior of p-phenylenediaminium guest binding with the inverted cucurbit[6]uril host

2015 ◽  
Vol 13 (30) ◽  
pp. 8330-8334 ◽  
Author(s):  
De-Qing Zhang ◽  
Rui-Lian Lin ◽  
Wen-Qi Sun ◽  
Zhu Tao ◽  
Qian-Jian Zhu ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Sandwich Structure ◽  
The Other ◽  
Binding Interaction ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Guest Binding ◽  
Different Types ◽  
Inclusion Structure

The binding interaction between inverted cucurbit[6]uril (iQ[6]) and p-phenylenediaminium has been investigated by X-ray crystallography, 1H NMR spectroscopy and ITC. Our data indicate that the host and the guest can form two different types of complexes: one is an inclusion structure and the other is a sandwich structure.

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