Recherches sur le benzofuranne,LVII. Sur une chloration inhabituelle de l'hétérocycle au cours de la réduction des (nitro-4 phényl)-2 ou -3 benzo-furannes par le chlorure stanneux

Reductions of 2-(4-nitrophenyl)- and 3-(4-nitrophenyl)benzo-furans by stannous chloride in presence of hydrochloric acid yield not only the expected 2-(4-aminophenyl)- and 3-(4-amino-phenyl)-2-chlorobenzofurans but also the 2-(4-aminophenyl)-3-chloro- and 3-(4-aminophenyl)-2-chlorobenzofurans the structures of which have been ascertained by their ¹³C nmr spectra, by comparison with those of 2-phenyl- and 3-phenylbenzofurans. These interfering chlorinations are most likely due to a radical mechanism.     

Sur un transformation inattendue de l'amino-3 nitro-2 benzofuranne par l'acide acétique

Pure or highly concentrated acetic acid slowly transforms 3-amino-2- nitrobenzofuran into 3-diazo-2,3-dihydro-2-benzofuranone, the structure of which has been confirmed by its spectroscopic characters as well as by its chemical reactivity     

Recherches sur le benzofuranne. LIX. Orientation de l'aroylation de l'éthyl-2 benzofuranne selon la nature du chlorure d'aroyle utilise

While both hindered and unhindered alkanoyl chlorides and some aroyl chlorides react with 2-ethylbenzofuran at the 3 position, most aroyl chlorides also react with 2-ethylbenzofuran at the 6 position and to a lesser extent at the 4 position.     

Réactions induites par ies halogénures de pyridinium. XXVII. Sur la formation d'ethers cycliques par action du chlorure ou du bromure de pyridinium sur l'hexanediol-2,5

It has been shown that cyclodehydration of 2,5-hexanediols into 2,5-dimethyltetrahydrofurans can be effected with pyridinium chloride or bromide as well as with any other reagent formerly used for the purpose. The various secondary reactions accompanying this cyclodehydration have been determined, and plausible mechanisms for the ring closure are outlined.     

Etude de l'acylation de l'acétyl-3 acétoxy-8 indolizine par action de chlorures d'acide en présence de chlorure d'aluminium

Study of acylation of 3-acetyl-8-acetoxyindolizine by miscellaneous acid chlorides in the presence of aluminium chloride shows that this reaction is either limited to a transesterification (in the case of benzoyl chloride) or leads to introduction of an acyl group in position 1 with simultaneous liberation of the phenol function in position 8. When acylation takes place, acetyl chloride resulting from the cleavage of the acetoxy group competes with the acid chloride used in the reaction. Predominant acylation by the latter is observed when the reaction is performed with ethoxalyl chloride or with non branched aliphatic acid chlorides; by contrast solely acetylation takes place when pivaloyl or phenylacetyl chloride is used. These results are tentatively explained by a process related to the Fries rearrangement. The hypothesis of intramolecular transfer of an acyl group from the ester function in position 8 can be discarded by the observed results.     

Sur une transformation inhabituelle de nitro-2 benzofurannes dans les conditions de la reaction de friedel et crafts

On treatment with acetyl chloride or acetic anhydride in presence of aluminium chloride in methylene chloride. 2-nitro and 5-chloro 2-nitro benzofurans yield 2,3-dichloro benzofurans, 3-chloro 2-coumaranones and 2-acetoximino 3-chloro coumarans. By the action of acetyl chloride, in presence of titanium (IV) chloride in methylene chloride, on 2-nitro benzofuran, 2,3-dichloro benzofuran can be obtained with a fairly good yield beside a relatively restricted quantity of 3-chloro 2-coumaranone. In the same conditions, 5-chloro-2-nitro benzofuran yields not only 2,3,5-trichloro benzofuran but also 2,2,3,3,5-pentachloro coumaran and, occasionally. 3,5-dichloro 2-coumaranone.     

Etudes sur les composés organométalliques I action du chlorure de benzylmagnésium et du bromure de phénylmagnésium sur le tétrachlorure de titane

The reactions between phenylmagnesium bromide or benzylmagnesium chloride and titanium tetrachloride have been studied. The influence of the introduction order of the reagents is mentioned. Decomposition of the (non-isolated) compounds R_nTiX_4-n is shown to be essentially intermolecular, and rarely intramolecular.     

Action du cyanure mercurique sur quelques halogénures de désoxy-3-trifluoroacétamido-3-D-ribofurannosyle. Note de laboratoire

Reactions of Some 3-Deoxy-3-trifluoroacetamido-D -ribofuranosyl Halides with Mercuric Cyanide The expected 2,5-anhydro-D -allononitrile 11 was obtained when the 2-O-benzoyl-3-deoxy-3-trifluoroacetamido-D -ribofuranosyl bromide reacted with mercuric cyanide, whereas the isomeric 1,2-O (1-cyanoethylidene) derivative was formed from the 2-O-acetylated halide; no reaction occurred when the halide was 2-O-p-nitrobenzoylated.     

Addition du chlorure de nitrosyle et de l'oxyde d'azote(III) sur l'allyltriméthylsilane et sur l'allylbenzyldiméthylsilane

Additions of Nitrosyl chloride and Dinitrogen trioxide to Allyltrimethylsilane and Allylbenzyldlmethylsilane. The reaction of nitrosyle chloride and dinitrogen trioxide with allyltrimethylsilane and allylbenzyldimethylsilane leads to nitrosochlorides and to pseudonitrosites. The structures of these compounds are proved by reduction to amines.     

Synthèse univoque du nitro-2 methoxy-3 benzofuranne et des naphtofurannes correspondants

3-Methoxyarenofurans were obtained from 3-counmaranone, from ts three corresponding isomeric naphtofuranones and from 7-methoxynaphtho[2,1-b]furan-1-one in good overall yields by carboxymethylation followed by saponification and subsequent decarboxylation, Their regioselective nitration in the 2-position was performed by successive treatment with t-butyllithium, trimethyltin chloride and tetranitromethane.     

Recherches sur le benzofuranne. LXII. Orientation de la nitration de benzofurannes substitués en 2 par un groupement électro-attracteur

Nitration of 2-acetyl-, 2-carbethoxy- and 2-cyanobenzofurans by nitric acid in acetic anhydride mostly succeeds on the 5 and 6 positions, and in some instances on the 4 position and possibly on the 7 position. Moreover, in the first two cases, the substituent     

Action du chlorure de nitrosyle sur le trichloréthylène et sur le tétrachloréthylène

Nitrosyl chloride is only chlorinating in darkness and above 100°. In the sun light and at room temperature it reacts as a chlorinating, nitrosating, nitrating and oxidizing agent. With trichlorethylene in fact pentachlorethane 1,1,1,2-tetrachloro-2-nitrosoethane, 1,1,1,2-tetrachloro-2-nitroethane, dichloracetic acid and a compound of empirical formula C₄H₂Cl₅NO₂ are obtained. Tetrachloroethylene carried to hexachlorethane, pentachloronitrosoethane and tetrachloro-2-(pentachlorethyl)-1,2-oxazetidine. Introduced nitrosyl chloride provided nitrogen monoxide prouved by gaz chromatography. This monoxide reacted afterwards to give nitrogen which is the single nitrogenous gazeous compound. Carbondioxide is a minor component of the gaz.     

Obtention d'hétérocycles par action de binucléophiles diazotés sur des chalcones: Influence du substituant en position 2

Reactivity of 2-susbituted chalcones against diaza binucleophiles (hydrazines, thiourea, guanidine) has been studied. Various heterocycles (pyrazoles, pyrazolines, pyrimidines) or substituted hydrazines were obtained. A general interpretation is given according to the substituent of the enone system, R, the nature of binucleophile and the medium.     

Précisions apportées au mécanisme de la polymérisation du chlorure de vinyle par le chlorure de tertiobutyle-magnésium en milieu tétrahydrofurannique. Etude par résonance magnétique nucléaire

NMR analysis of the low molecular weight poly(vinyl chloride) obtained from polymerizations initiated by t-BuMgCl in THF solution suggests that all the polymer chains have the structure: Enhanced signal/noise ratio by NMR spectrum accumulation confirms this structure in products of higher molecular weights. Examination of the NMR spectrum of vinyl chloride monomer in THF solution reveals the formation of a monomer–THF complex; it seems that the initiation step of the polymerization is governed by this complexation phenomenon.     

Sur la synthèse d'alkoxy-2 nitro-3 2H-chroménes

2-Alkoxy-3-nitro-2H-chromenes have been obtained by the reaction of β-nitroacetaldehyde dialkyl acetals with some salicylic aldehydes in the presence of triethylamine p-toluene sulfonate.     

Sur l'orientation et les anomalies de l'acetylation des Bz-méthoxy nitro-2 benzofurannes

4-Methoxy-, 5-methoxy- and 7-methoxy-2-nitrobenzofurans have been acetylated via the Friedel-Crafts reaction under the same reaction conditions. 2-Nitrobenzofuran does not undergo acetylation while 6-methoxy-2-nitrobenzofuran only produces decomposition products. As a result of the positive acetylation reactions, 7-acetyl-4-methoxy-, 4-acetyl-5-methoxy- and 4-acetyl-7-methoxy-2-nitrobenzofuran have been prepared. As side products in the acetylation reactions, 4-methoxy-3-(4′-methoxy-2′-nitro-7′-benzofuranyl)-2,3-dihydrobenzofuran-2-one was isolated when 4-methoxy-2-nitrobenzofuran was the starting material and, likewise, when 5-methoxy-2-nitrobenzofuran was the starting material, 3-chloro-5-methoxy-2,3-dihydrobenzofuran-2-one was obtained. Furthermore, 5-methoxy-2-nitrobenzofuran participated in an unexpected chlorination leading to 4-chloro-5-methoxy-2-nitrobenzofuran.