Synthèse de systèmes comportant deux cycles thiophéniques orthocondensés à un hétérocycle à sept chainons

The reduction of the carbonyl group of bithienyls carrying on each thiophene ring a formyl group bonded to the carbon atom next to the intercyclic bond leads to the expected primary di-alcohols. These dialcohols can give the corresponding bis-halogeno-methylated bithienyls. The dehydration of the alcohols and the action of sodium sulfide or amines upon the obtained halides leads respectively to the dihydrodithieno[c,e] oxepines, thiepines and azepines. The tetramethyl derivatives of the previous oxepines have been obtained from diacetylbithienyls.     

Synthèse de composés cyclopentaniques chiraux,di, tri et tétrasubstitués. Application à la synthèse de dérivés Oxa-13-prostanoïques

The cyclopentenecarbaldehyde 1a , acetals 2a , 2b and the cyclopentenone 2c have been transformed through regio and stereocontrolled reactions into a variety of enantiomerically pure substituted cyclopentanes. Using appropriately selected Wittig reagents, aldehyde 1a furnished the condensation products 3 , 4 , 5 . Michael addition of diethyl malonate on the α,β-unsaturated aldehyde 1a under phasetransfer conditions led efficiently to 7 . Reduction of the cyclopentenone 2c gave 21 in high yield. The cyclopentenes 2a , 2b and 23 , submitted to hydroboration-oxidation furnished the cyclopentanols 10 , 13 and 24 , respectively, in 30, 70 and 50% yields, reflecting the substitution pattern of the starting alkenes. The salient feature of these reactions is the stereospecificity due to the chiral centre of the molecules 1a , 2a , 2b and 2c , leading to compounds with two, three and four asymmetric centres. The straightforward synthesis of 11α-hydroxy-13-oxaprostanoic acid 20 is described and an approach towards the preparation of 9α, 11α-dihydroxy-13-oxaprostanoic acid 34 is also presented. The structure of these products has been determined by ¹H- and ¹³C-NMR spectroscopy.     

Synthèse et propriétés des aroylhydrazones du benzoate d'éthyle. Synthèses d'hétéroscycles azotes

The aroylhydrazones of ethyl benzoate have been prepared in fair yield by the action of aroylhydrazines on ethyl benzimidate hydrochloride. These products give rise, quantitatively, at their melting point, to 5-aryl-2-phenyl-1,3,4-oxadiazoles, and, in the presence of hydrazine hydrate, in boiling 1-propanol to 4-amino-5-aryl-3-phenyl(4H)-1,2,4-triazoles (Yields 50%). The addition of methylmagnesium iodide to these products give aroylhydrazones of acetophenone.     

Une synthèse générale des tétraazamacrocycles mono-C-fonctionnalisés

A General Synthesis for Mono-C-Functionalized Tetrazamacrocycles A new synthesis, under usual conditions of concentration, medium, and temperature, of a series of mono-C-functionalized tetraazamacrocycles is given. The method may easily be generalized. The new procedure allows the modification of the length of the side-chain or the size of the cavity by choosing fitted staring materials. The key intermediate has a tosylated linear side-chain susceptible to be transformed into a large variety of functional groups.     

Synthèse d'oxaphénalènes substitués en position 2 par un groupement électro-attractif

Up to now, little is known about naphtho[1,8-bc]pyran (oxaphenalene) derivatives, although some of them have been detected in the vegetable kingdom. However, very recently [6], 2-nitronaphtho[1,8-bc]pyran and 6-methoxy-2-nitronaphtho[1,8-bc]pyran proved to be powerful mutagenic agents (the most efficient on mammal cells in culture hitherto known). This fact prompted us to investigate further this class of products by studying compounds bearing an electron-withdrawing group in the 2-position. We report in the present paper that, in certain cases, this synthesis can be achieved by the yet unattempted péri-heterocyclization of 8-hydroxy-1-naphthaldehydes with an halogenated active methylene compound in acetone in the presence of potassium carbonate. Thus, among others, 2-acetyl, 2-benzoyl and (4-methoxybenzoyl)naphtho[1,8-bc]pyrans, as well as the corresponding derivatives bearing a methoxy group in the 6-position have been prepared. Nevertheless, such a condensation according to Rap [1] cannot be carried out in certain cases, particularly with acetonitrile.     

Composés hétérocycliques à partir (testers cyaniques. 4. Synthèse de nouvelles aroxy-2 quinazolinones-4

The cyclisation of ethyl anthranilate and ethyl N-methyl-anthranilate with aryl cyanates, catalyzed by benzoic acid, provides a simple and general method in high yields for the synthesis of 2-aroxy-4-quinazolinones and 2-aroxy-l-methyl-4-quinazolinones.     

Systèmes aromatiques à 10 électrons π derivés de l'aza-3a pentalène. XVII. Tautomérie azido/tétrazole dans la série du pyrazole

The IR and NMR study of twelve 3- (or 5-) azidopyrazoles shows that the azide is the only tautomer present under neutral conditions. The most stable isomer (tautomer) is 3-azido in N-acetyl and N-H derivatives. 3-Azidopyrazoles are the only polyazoles in which coupling with the N-H in NMR (solvent: DMSO) is observed. In a basic medium, the corresponding anions of the 3-azidopyrazoles N-H are formed: these anions slowly evolve, following first-order kinetics, to the bicyclic anions of pyrazolo-[1,5-d] tetrazoles, derived from 3a-azapentalene. This evolution has been checked by means of IR and NMR spectroscopy.     

Synthèse d'hétérocycles dérivés du (+)-camphre

Diamines react with 3-dimercaptomethylenecamphor giving either a bis-oxothioamide or a heterocyclic compound via in oxoaminothioamide intermediate. In this last reaction, there is cleavage of both C? S bonds. Similarly, diamines react with β-oxothioamides to produce the same heterocyclic derivatives. In these reactions, a transamination is involved and the carbonyl group of camphor is preserved. A distinctly different reaction occurs when the same camphor derivatives are treated with hydrazine; thioxo- alcoylamino- or arylaminoindazoles are then obtained. Ring closure occurs on the carbonyl carbon of the camphor molecule.     

Synthèse d'azido dithiényl-1,2 éthènes et éthanes

Two convenient preparations of azido-1,2-dithienylethenes are described. The synthesis of azido-1,2-dithienylethanes proceeds via metalation (n-Buli) and subsequent treatment by tosylazide of bromo-1,2-dithienyl-ethanes. The structures of the obtained derivatives were established on the basis of ¹H nmr, ir, and mass spectral data.     

Propriétés thermodynamiques des mélanges binaires. Volume et énergie interne de formation des solutions de l'hexadécane dans les isomères de l'hexane

The volumes of mixing of hexadecane and each of the isomers of hexane have been measured for the equimolar mixtures at 20°C. The results have been used together with previously measured values of ΔH to obtain ΔU_v. A very good correlation is found between the energy of mixing and the properties of the pure alkanes.     

Structure électronique de dérivés sulfurés : Partie V. spectres électroniques d''hétérocycles thio-carbonylés

The experimental and theoretical spectra of thiocarbonyl heterocyclic compounds with two heteroatoms in the position to the thiocarbonyl group have been studied.

The theoretical interpretation of the CNDO/S results including an extension to the third period, i.e. 3d orbitais, is in good agreement with the saturation effect as well as with the influence of the intracyclic heteroatoms on the typical absorptions of the thiocarbonyl group.     

Hétérocycles à fonction quinone. 7. Benzo[f]quinazolinediones-7,10 à action antitumorale potentielle

Few benzo[f]quinazoline-7,10-diones 4a-c are prepared by oxidation, with potassium nitrosodisulfonate, of the corresponding benzo[f]quinazolinamines, made by reduction of the nitro analogues which were obtained from 8-methoxybenzo[f]quinazolin-1(2H)-one. The compound 4a shows an interesting cytotoxicity.     

Propriétés électriques du trioxyde de tungstène a proximité de sa composition stoechiométrique. Influence des conditions thermodynamiques de préparation et phénomènes de trempe

The experimental study of variations in electrical conductivity of WO_3−x vs oxygen partial pressure and temperature shows evidence of interstitial W⁶_i· as being the major defect. Under certain conditions, point defects can order themselves in extended defects. The behavior of electrical conductivity can be interpreted in terms of thermodynamic equilibrium between point defects and extended defects, the latter leading to structural modifications beyond a certain departure from stoichiometry. Moreover, WO_3−x shows evidence of quenching phenomena allowing it to keep electrical features characteristic of high temperatures down to room temperature. These properties may explain discrepancies between previous data.     

Substitutions homolytiques intramoléculaires. 17. Décomposition de peroxydes de ϵ-alcényle et de t-butyle. Accès à des tétrahydropyranes substitués

The induced decomposition of t-butyl hex-5-enyl peroxide in good hydrogen donor solvents led to 2-substitude tetrahydropyrans and adduct peroxides. The presence of substituents on the hexenyl moinety influenced seriously the relative ratio of the heterocycle and the adduct peroxide.     

Synthèse d'hétérocycles polycondensés à partir de benzopyranno-1 as-triazinones

From benzopyranno-1-as-triazinones 1 and 2 , chloro, hydrazino and aminobenzopyranno-1-as-triazinehsa ve easily been prepared by transformation of the carbonyl function. These compounds lead to triazolo and imidazolobenzopyranno-1-as-triazines by reaction with acids or α-bromoketones. Tetrazolotriazines have been obtained by reaction of sodium nitrite with hydrazinotriazines.     

β-Dicéto énamines hététrocycliques: 1. Indanediones-1,3 substituées en 2 par un hétérocycle azoté

The condensation of methylated N-heterocycles and espically monomethyl- and polymethylpyridinets on phthalic enhydrides leads to 2-ary1-1,3-indanediones. The 3alklidenylphthalides formed in an intermediary state have been isloated. The influence of solvents and temperature on the velocity and yeild of formation of 2-(2- and 4-pyridyl)-1,3-indandiobnes has been studies. The ir and nmr spectra confirm taht these compunds exist under a β-diketoenamine form resonating witj a betaine form.     

Synthèse, à partir du (+) — camphre,d'hétérocycles dérives des tétrahydroxanthone,tétrahydroacridone,tétrahydroacridine et octahydroacridine

Derivatives of acridine, acridone and xanthone were prepared from (+)-camphor, 3-Arylidene, 3-arylmehtyl or 3-aroylcamphors with an halogen in the ortho position and dibornanonylarylmethanes may be uased aas precursors. Ring closure may be induced by ammonia, armoatic amines or potassium hydroxide with or without a catalyst. Good yaields were obtained. In come casaes, the reaction goes with an aromatisation of the heterocyclic moiety.     

Polymères à propriétés pharmaceutiques potentielles. III. Etude sur molécules modèles

4-Methyl, 4-octene model molecules of the 1–4 polyisoprenic chain have been chemically modified in corresponding alcohol and chloroformate. These model molecules have been allowed to react with pharmaceuticals such as testosterone, cholesterol, and quinine to link the drug with a carbonate bound. Spectral data of these compounds are compared to those of previously synthetized polymers with potential pharamaceutical properties.     

Fluorénacènes et fluorénaphènes Synthèses dans la série des indéno-fluorènes,XIX Dérivés tétraméthylés du trans-fluorénaphène et du trans-fluorénacène

By condensation of isophthaloyldichloride resp. of terephthaloyldichloride with 4-bromo-1,2-xylene according Friedel-Crafts, followed in each case by a double cyclisation and a final reduction, the 2,3,9,10-tetramethyl-7,12-dihydro-indeno[1,2-a]fluorene resp. the 2,3,8,9-tetramethyl-6, 12-dihydro-indeno[1,2-b]fluorene are synthesized.     

Etude dans la série des radicaux hétérocycliques: partie XIV. Radicaux diméthyl-3, 4-isoxazolyl-5. Réactivité en série aromatique et hétéroaromatique: nouvelle voie d'accès à des diméthyl-3, 4-isoxazoles subsitués en C(5) par des groupements aryle et hétéroaryle

The aprotic decomposition of 5-amino-3, 4-dimethyl-isoxazole with excess isoamyl nitrite in aromatic solvents (alkylbenzenes, polyalkylbenzenes, anisole etc.) and in heteroaromatic solvents (thiophene, 2, 4-dimethylthiazole, pyridine, 4-alkylpyridines, dimethyl- and trimethyl-pyridines) leads to 5-aryl- and 5-heteroaryl-isoxazoles in yields of about 40%. This method provides a new way of obtaining 5-iodo-3, 4-dimethyl-isoxazole by the aprotic decomposition of the corresponding amine in the presence of iodine (yield: 30%). The relative reactivity of the 3,4-dimethylisoxazol-5-yl radical in alkyl benzenes, in anisole and in alkylpyridines is very similar to that of other heteroaromatic radicals with the radical site next to a sulfur or an oxygen atom. The radical shows electrophilic character because of the inductive effect of the oxygen atom. In the pyridine series an abnormally high percentage of 2-substitution occurs. This may be explained by a solvatation effect. The characteristic GLC., NMR. and MS. data are reported for most of the compounds studied.