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.     

Reactions SRN1 en serie heterocyclique: I - reactivite de sels de nitro-5 tetrahydrooxazines-1,3

Heterocyclic nitronate anions prepared from 3-ethyl-5-hydroxymethyl-5-nitrotetra-hydro-1,3-oxazine are found to be suitable nucleophiles for S_RN1 reactions. Base-promoted nitrous acid elimination from C-alkylation product gives rise to new tetrahydro-1,3 oxazines with a trisubstituted ethylenic double bond in the 5 position.     

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.     

Synthesis of nitro- and aminoindoles

Optimal conditions are proposed for the direct nitration of 2,3-dimethylindoles containing methyl and methoxy groups in the benzene ring. In contrast to 5- and 6-methylindoles and 5- and 6-methoxyindoles, nitration of 7-methyl-and 7-methoxy-2,3-dimethylindoles proceeds differently under the same conditions. A series of previously unreported aminoindoles was obtained by reduction of the nitroindoles.Mordova State Pedagogical Institute, 430007 Saransk, Russia; e-mail:mgpi@si.moris.ru and M. V. Lomonosov State University, 119899 Moscow, Russia, e-mail:yumar@org.chem.msu.su. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1630–1636, December, 1999.     

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     

Synthesis of nitro- and aminoalkylphosphonates

Conclusions Some new O, O-dialkyl nitroalkylphosphonates were synthesized by the addition of dialkyl phosphites and thiophosphites to nitroolefins. The corresponding aminophosphonates were obtained from them by reduction. The hydrolysis of the latter gave the corresponding aminoalkylphosphonic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1164–1168, May, 1972.     

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.     

Synthèse de derivès du nitro-5 imidazole potentiellement actifs en chimiothèrapie

The synthesis of six derivatives of 2-methyl-5-nitroimidazole 1-substituted by a CH₂CH₂Het group (Het being a pyridinium or a 1-substituted imidazolium) has been carried out. A careful ¹H and ¹³C nmr study of these compounds and other nitroimidazoles has been made. None of the synthesized compounds show any significant cytostatic kactivity.     

Acetylenic derivatives of nitro- and aminonaphthalenes

Conclusions We synthesized a number of acetylenic and diacetylenic alcohols, which are derivatives of nitro- and aminonaphthalenes by the condensation of substituted halonaphthalenes with acetylenic alcohols.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 407–409, February, 1984.     

Cyclisation de dinitrodiarylamines en nitro-3 carbazoles inhibition sterique de la substitution nucleophile SNAr par effet ortho d'un groupement methyle

As a first step in the total synthesis of pyrido [4, 3-b] carbazoles, the S_NAr reaction of p.aminophenol is very easy with chlorodinitrobenzene but is hindered when a methyl group is adjacent to the nitro groups.     

Benzindoles. 24. Reduction of nitro-2,3-dimethyl[4,5]- and nitro-2,3-dimethyl[6,7]benzindoles

The reduction of nitro-2,3-dimethyl[4,5]- and -[6,7]benzindoles was studied; Benzindoles were obtained with an amino group in the benzene ring. Individual isomers can be separated as the acyl derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1481–1484, November, 1986.     

Mass-spectrometric behavior of isomeric nitro- and nitroaminoindolizines and indoles

Peaks of [M — NO]⁺ and [M — NO₂]⁺ ions are characteristic for the mass spectra of nitroindolizines, whereas peaks of ions of the indole type, viz., [M — HCN]⁺ and [M- H,- HCN]⁺ (for alkylindoles), are not characteristic. In the mass spectra of nitroindoles the latter ions give more intense peaks, while the loss of a nitro group or its rearrangement is a considerably less significant process. When a dialkylamino group is introduced in the nitroindolizine molecule, the primary processes in the fragmentation of such compounds are due to fragmentation of the alkylamino group.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 765–768, June, 1982.     

Planar and out-of-plane normal vibrations of nitro- and aminobenzenes

The normal vibrations of halogenobenzenes with a polyatomic para substituent (NO₂, NH₂ ) are reported.The specific vibrations of NO₂ and NH₂ groups and of the CN and CX bonds (X is F, Cl, Br, I) have been assigned using the G.F. method of Wilson. The potential energy distribution shows that the inplane and outofplane vibrations of CN bonds exhibit different behaviour in nitro and aminobenzenes. Indeed, the CN stretching and planar bending are vibrational modes coupled respectively with the symmetric deformation and rocking of NO₂ whereas in the case of the amino molecules they are coupled with the skeletal modes only. Consequently the CN planar bending vibrations have frequencies lower than the CX ones in the nitro compounds. In contrast, the CN bending frequencies are higher in the amino molecules. For the outofplane bending of amino and nitro molecules the γ(CN) frequencies are always higher than γ(CX) frequencies because there is no coupling with the wagging of the polyatomic substituent. Our experimental results by Raman spectroscopy are in good agreement with the theoretical calculations we have performed. They also agree with the spectra published by other authors. We have recorded the splitting of some NO₂ bands in pdinitrobenzene, which is probably due to isomeric positions of the two NO₂ groups relative to the plane of the skeleton.