Synthese et proprietes ionophores de macrocycles tetrapyrazoliques

The synthesis of a tetraaza-porphyrinogen tetra-substituted by dimelhylamino groups (electrodonor groups) has shown the influence of those substitutions above the ionophoretic properties of this macrocycle. The complexation of alkali, ammonium and calcium cations by these compounds has been studied by the extraction method. In all cases, the complexing ability of the substituted compound is higher than its unsubstituted homologue. This effect is less pronounced for the transport of the same cations across a liquid membrane.     

Prototropie et synthèses nouvelles dans la série des dihydro-5,6 hydroxy-4 pyrones-2 et pyridones-2

The multistep catalytic reduction of 6-methyl-4-hydroxy-2-pyrone allows isolation of two intermediate compounds: the biologically active parasorbic acid ( 5 ) and the 6-methyl-5,6-dihydro-4-hydroxy-2-pyrone ( 2 ). The desmotropic keto-enol equilibrium lies on the enol side, with the 4rhydroxy structure. Primary arylamines readily react with 2 , leading to corresponding 2-pyridones 8 ; with methylamine, the aliphatic intermediate 7 resulting from ring attack at the 2 position can be isolated. Also further functionnalization of both dihydropyrone and 2-pyridone is possible by selective bromination at position 3.     

Telomeres photoreticulables—2. Synthese de telomeres photoreticulables a partir des hydroxy-2-ethyl acrylate et methacrylate et des β-cinnamoyl oxy ethyl acrylate et methacrylate

Photocrosslinkable telomers based on cinnamoyl derivatives of polyacrylates and methacrylates can be prepared either by reaction of cinnamoyl chloride with telomers of hydroxy-2-ethyl acrylate and methacrylate, or by direct telomerisation of β-cinnamoylethyl acrylate and methacrylate. The first method gives products containing at least 70% of the theoretical maximum olefinic unsaturation but with low $\text{DP}$_n [1–20]; the second method gives telomers of high $\text{DP}$_n with the maximum number of cinnamoyl side-chains.     

Action des composes organomagnesiens sur les pyrones-2-VII : Etude de la stabilite relative des hydroxy-6 dihydro-5,6 2h-pyrannes et des cetols tautomeres correspondants

In the reaction between organomagnesium compounds and 2-pyrones, the relative stability of the 6-hydroxy 5,6-dihydro 2H-pyrans and their tautomeric forms (ketols) has no influence on the reaction pathway. When ethylenic ketols are obtained, the corresponding tautomeric dihydropyranols are prepared in a selective way by reaction of nucleophilic reagents on the 3,6-dihydro-2-pyrones. In the other hand, the exclusive formation either of the dihydropyranols or of the unsatured ketols E, during these two reactions, shows up that here is no equilibrium between these two entities in the experimental conditions.     

Stereochimie de la cycloadditton des diarylnitrilimines sur les n-alkyl et les dialkyl-1,2 dihydro-1,2 isoquinoleines

The PMR spectroscopic properties (60 MHz) of cycloadducts of diarylnitrilimins towards 1,2-dihydroisoquinolines mono alkylated at the N-atom or dialkylated at the C¹ -carbor and N-atoms have been studied.Date allow us to determine the stereochemistry of the cycloaddition reaction which is regio and diastereospecific. Configuration and conformation of the cycloadducts are specified.     

Synthese et proprietes d'ethers β-monofluores

Two methods have been used for the synthesis of β-monofluorinated ethers. One is the methylation of α-fluorinated alcoholates obtained from corresponding 2-fluoroalcohols by action of NaH in T.H.F. The second method is the nucleophilic substitution of tosyl group by fluorine in 2-methoxy-tosylates. Spectral properties of these β-fluorinated ethers have been studied. Furthermore ¹⁹F N.M.R. spectrum of the E 2-methoxyfluorocyclohexane has been investigated at low temperatures.     

Heterocycles tellures:Synthese et proprietes de tellurochromannones-4

A general method of preparation of tellurochromanones is described by Friedel-Crafts intramolecular cyclisation of the corresponding acids. The structure was determined by chemical evidence, analysis, uv, ir and nmr spectra. The first tellurochromannols and tellurochromene are also described.     

Relations entre les caracteristiques physico-chimiques des charges et les proprietes mecaniques des polymeres (PVC) plastifies et charges

Some rheological and mechanical properties of polyvinyl chloride filled with up to 80 phr CaCO₃ have been evaluated with a view to rationalizing results in terms of polymer/filler interfacial interactions. These interactions have been characterized by inverse chromatography using a series of acid-base vapour probes selected from literature classifications. Both pure and industrially pretreated CaCO₃ samples were employed; in addition, one of the pure materials was surface-modified by exposure to selected vapours in a microwave plasma apparatus. Though the data are not adequate to develop exact correlations linking interaction parameters and the physical properties of the filled systems, it is clear that favourable interaction (wetting, adhesion) states at the polymer-filler interface promote ease of dispersion of solids in the molten polymer, enhance mechanical properties (such as elongation at break and the yield stress in the stress/strain curve of the materials) and reduce the rates at which these properties deteriorate when compounds are exposed to weathering. This preliminary work therefore confirms the apparent importance of interfacial effects to property development in filled polymers, suggests the usefulness of acid-base concepts as an index of these effects, and shows inverse chromatography data to be convenient for their quantification. Plasma treatment appears to be a particularly flexible approach to the tailoring of diverse surface properties in filler particles. Detailed development of the various concepts is indicated.     

Reactions retrodieniques XIII - thermolyse eclair des (Z) et (E) dihydroxy-11, 12 ethano-9,10 dihydro-9,10 anthracenes : synthese des (Z) et (E) ethenediols-1,2

The flash vacuum thermolysis of diols $\text{3}$ and $\text{4}$ affords, via a retro-Diels-Alder cleavage, the simplest enediols $\text{1}$ and $\text{2}$ for which the NMR and IR spectra as well as their thermal evolution are reported.     

Synthese de F-alkyl-2 hydroxy-4 quinoleines

F-alkynes and F-alkynyl esters are versatile intermediates for the synthesis of F-alkyl substituted heterocyclic compounds.Condensation of these compounds with aniline and its derivatives, followed by cyclisation of intermediates obtained (enamines and imines), is in fact the only way of synthesis of hydroxy-4 quinolines substituted in position 2 by a F-alkyl chain other than CF₃.     

Synthese et caracteristiques spectrales de f-alkyl-2 dihydro-3, 4 oxo-4 quinazolines

In this paper, we report the preparation of a series of 4(3H) quinazolinones substituted in the 2 position by a linear perfluoroalkyl-chain with R_Fas C_n F_2n+1(n=1, 3, 5, 7).These compounds are obtained in two steps, action of F-acid chlorides on 2-aminobenzonitrile which affords the corresponding F-amides followed by cyclization of this intermediate with alkaline hydrogen peroxide. We isolated a reaction intermediate in the cyclization of N-(2-cyanophenyl) F-octanamide. All compounds were identified by the usual spectroscopic methods (IR, NMR¹H, ¹⁹F, mass spectrometry).     

Action du fluorure de potassium sur les tosylates α-fluores: Synthese et proprietes de derives 1,2-difluores.

Fluorinated alcohols, synthesised from epoxides by action of trimethylamine fluorhydrate, can be transformed to 1,2-fluorotosylates when they are treated with tosyl chloride in pyridine. The physico-chemical propreties of these fluorotosylates are studied. The action of KF, in diethylen glycol, on these α-fluorinated tosylates gives the corresponding 1,2-difluorinated compounds in good yield. The stereochemical course of the last reaction can be elucidated from an analysis of the ¹⁹F NMR of the 1,2-difluorocyclohexane.     

Beiträge zur Chemie des Phosphors. Synthese und Eigenschaften des 1,2-Diphospha-3,4-diboretans (t-BuP)2(BNMe2)2

Contributions tot he Chemistry of Phosphorus. 148. Synthesis and Properties of the 1,2-Diphospha-3,4-diboretane (t-BuP)₂(BNMe₂)₂ The first 1, 2-diphospha-3,4-diboretane (1,2-diphospha-3, 4-diboracyclobutane) (t-BuP)₂(BNMe₂)(1) was prepared by [2+2] cyclocondensation of K(t-Bu)P? P(t-Bu)K with Cl(Me₂N)B? B(NMe₂)Cl. 1 could be isolated in the pure state and was NMR spectroscopically characterized as a compound with a planar P₂ B₂ ring skeleton.     

Heterocyclisations des hydroxy-6 methoxy-2 hexene-2 et heptene-2 oates de methyle.

Tetrahydropyran derivatives – and – are formed in good yields by cyclisation of methyl-6-hydroxy-2-hexenoate or 2-heptenoate mediated by various electrophilic reagents (mCPBA, benzeneselenyl chloride, N-bromosuccinimide, iodine). Cyclisations of Z and E isomers are stereospecific. The diastereoselectivity of cyclisation of the secondary alcohol varies with the nature of the electrophilic reagent.