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.     

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     

Synthèse d'analogues furanniques et nitro-2 furanniques du diméthyl-7,12 benzanthracène

A route to 1-formyl-2-hydroxy-9-methylanthracene and 1-formy 1-2-hydroxy-9,10-dimethylanthracene is desribed. These two aldehydes were further converted into mono- or dimethylanthra[2,1-b]furans, besides the corresponding acids and esters, by condensation with ethyl bromoacetate. The related mono- or dimethyl-2-nitroanthra[2,1-b]furans were also prepared by reaction between the above aldehydes and bromonitromethane, followaed by heating in toluene in the presence of p-toluene-sulfonic acid.     

Sur une attaque inhabituelle de l'hetérocycle du benzofuranne,par action de chlorure de sulfuryle sur l'acétamido-3 nitro-2 benzofuranne

Sulphuryl chloride transforms 3-acetamido-2-nitrobenzofuran into 3-acetylimino-2-chloro-2-nitro-2,3-dihydrobenofuran instead of proceeding to the expected chlorination. When the reaction was carried out in the presence of an alcohol, 3-acetamido3-alkoxy-2-chloro-2-nitro-2,3-dihydrobenzofuran was obtained.     

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.