Synthese de polymeres a proprietes pharmacologiques. Introduction de sequences peptidiques au sein de la chaine macromoleculaire

The introduction of peptidic sequences into polymers with pharmacological properties may increase the biocompatibility of the macromolecular prodrug. The synthesis of polypeptides from N-carboxyanhydrides bearing the active principles defines this objective. The l-lysine blocked as copper complex reacts with steroidic chloroformates (cholesterol-testosterone). After deblocking of the complex and treatment by phosgene, the corresponding N-carboxyanhydrides are obtained. Polymerization and copolymerization (with glycine N-carboxyanhydride) give oligopeptides bearing steroidic backbone as side-group. The low molecular weight of the synthesized compounds, the limited water solubility and the presence of secondary products limit the development of the method. Pharmacological tests are being undertaken to study delayed effects due to slow release of the steroid, to compare the biocompatibility of such prodrugs.     

Synthese anionique de polymeres comportant une fonction vinylsilane a l'une ou aux deux extremites de la chaine macromoleculaire

The reaction of vinyldimethylchlorosilane with a living polymer (ω or α,ω carbanionic) leads under certain conditions to the quantitative formation of a vinylsilane group to one or two ends of the macromolecular chain.     

Synthese et application de nouveaux sulfures a chaine perfluoree

Metallation of thiols R_FC₂H₄SH followed by alkylation with iodides R′_FC₂H₄I leads either to symmetrical or to unsymmetrical sulphides R_FC₂H₄SC₂H₄R′_F (with R_F=R′_F or R_F ≠ R′_F). All compounds obtained are good solvents of gases (particularly O₂, CO, CO₂, N₂).This property allows their application as biological carriers of dissolved gases.     

Synthese de polymeres possedant des fonctions du type carbonate-alcool et thiol carbonate-alcool en extremites de chaines

Anionic polymerization permits the synthesis of polymers having various functional endgroups by deactivation of living polymers with the aid of electrophiles. These functional end-groups, as in the case of low molecular weight polymers, are easily accessible to reagents and can be subjected to chemical modification. Using this method, it is possible to obtain oligomers carrying functional end-groups of types which cannot be created by direct polymerization. This technique was applied to the synthesis of polydienes having carbonate alcohol and thiolcarbonate alcohol functional end-groups. These end functions were obtained by chemical modification of existing alcohol groups. In order to specify the experimental conditions, a model study of such a reaction was carried out. The polymers and their models are characterized by NMR, i.r. and physico-chemical measurements. This type of chemical modification leads to prepolymer having easily hydrolysed carbonate and thiolcarbonate linkages, reactive points for the subsequent degradation of the corresponding reticulated systems.     

Synthese de materiaux polymeres transparents. Partie I Synthese du trifluoroacrylate de trideuteromethyle

The acrylic ester F₂CCFCO₂CD₃ is prepared from a mixture of difluorotetrachloroethanes CFCI₂CFCI₂ and CF₂CICCI. The dehalogenation of these Freons, followed by the addition of CFCI₃ by means of AICI₃ leads to a mixture of chlorofluoropropanes. The hydrolysis with oleum gives the acid chlorides which are then esterified by CD₃OD. The dehalogenation of the mixture by the zinc stirred in oxalic acid enables isolation of the expected ester by distillation. This compound, the refractive index of which n²⁰_D=1.3667 does not show a major absorption in the near infra-red between 0.6 and 1.4 μm. Thus the corresponding polymer is likely to provide a good material for the core of optical fibers.     

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.     

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.     

Synthese,caracterisation et reactivite de polymeres porteurs de fonctions chloroformiates

Chemical modification of low molecular weight polymers having functional groups along the chain, can lead to new macromolecular compounds which direct synthesis cannot be studied by classical polymerization ways. Synthesis of polymers possessing chloroformate groups has been obtained by a double modification reaction of polydienes backbones. Reactivity of new functions has been used for fixation of various organic compounds on the macromolecular chain. On the resulting polymers, the organic products are linked by carbonate, urethane or thiolcarbonate bounds varying with the nature of starting molecules: alcohol, amine or thiol which has reacted on the chloroformate groups.     

Synthese de sucres a chaine allongee heptose et octose par c-acylation nucleophile

The synthesis of extended chain; heptoses and octoses was achieved by nucleophilic C-acylation using carbanions derived from 1,3-dithiane 1 and 2-methyl-1,3-dithiane 10 on 1,2:3,4-di-O-isopropylidene-α-d-galacto-1, 5-hexodialdopyranose 2. The diastereoisomeric products 3 and 4 or 11 and 12 are formed in different proportion according to the solvent used. 11 was transformed by azidolysis into dithiepane derivatives 14, 15 and 16. From the intermediate 12, the diol 18, a precursor of lincosamine, was obtained.     

Preparation et etude des proprietes complexantes de polycondensats contenant des diazapolyoxamacrocycles dans la chaine principale

Some diazapolyoxamacrocycles have been polycondensed with different difunctional compounds to give polymers and gels. Their synthesis and their complexing properties towards alkali metals and calcium cations are reported.     

Synthese de polymeres liquides par reaction de telomerisation entre le butadiene et le tetrachlorure de carbone

This abstract deals with the telomerization of butadiene with carbon tetrachloride. By changing experimental conditions (the nature of the catalyst [Cu⁺, Cu²⁺, Fe³⁺, Fe (CN)₆^3?, Fe (CN)₆^4?, Mg], the ratio “r” of the concentration of taxogen to that of telogen, the ratio “c” of the concentration of catalyst to that of telogen) we have obtained chlorinated liquid polymers; their molecular weights range between 208 and approx 70,000. The dispersity of these polymers is calculated to be between 1.4 and 1.6. Addition 1–4 is the most frequent, (>80%). The correspondence between ratios r and c and the average molecular weight is established.     

Comportement en photooxydation de quelques polymeres du chlorure de vinyle contenant des structures oxygenees

We have studied the photooxidation of PVC samples modified by introduction of oxygen, carbon monoxide or acetylenic diester (ADCE) in the polymerisation medium. The presence of O₂ and (or) CO results in photosensitization, principally due to the conjugated polyenes. These groups are formed in a zip elimination reaction initiated by thermolabile oxygenated groups such as α-chloro peroxide or β chloroketones. The fumarate structures, formed during the PVC-ADCE copolymerization, play a stabilizing role at a concentration near to 0.10%. The inhibition mechanism has not been elucidated.     

Evolution des complexes catalytiques de rhodium supportes sur polymeres en catalyse d'hydrogenation

A set of styrene—chloromethylstyrene—divinylbenzene macroporous copolymers was phosphinated and treated with chlorocarbonyl rhodium and chlorophosphino rhodium complexes. The influence of the porous texture and functional group density of the resin on phosphination, fixation of the complexes and their extractibility by triphenylphosphine was studied. Measurement of their catalytic activity with respect to hydrogenation of hexene and benzene was carried out, before and during an ageing treatment under hydrogen or argon for up to 30 days. Results are very complex and suggest the existence of several families of active sites, their nature being discussed. Once again it is found that the structure of the support has a large influence on the evolution of catalytic activity.     

Synthese de polyphosphonates et polyphosphonamides a partir de monomeres diphosphoniques polycondensation en solution

Synthesis of linear polyphosphonates and polyphosphonamides is achieved by polycondensation in solution of aromatic diols and diamines with alkyldiphosphonyl tetrachlorides, in the presence of a hydrochloric acid trapping agent (triethylamine). The main limiting factors for chain growth are the insolubility of the polymers and the occurrence of side reactions.     

Synthese de polymeres porteurs d'un antivitamine k, la phenindione

Synthesis of methacryl monomeric derivative of phenindione (vitamin k antagonist) has been achieved. These new monomers, characterized by NMR and i.r., have been polymerized by a radical process. Resulting homopolymers have been analysed and compared with polymers bearing phenindione, previously synthesized by chemical modification.     

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.