Henry condensation at high pressures

The hitherto inaccessible nitroolefin (VII), which is the most convenient intermediate for the synthesis of the psychotropic amine (VIII), has been obtained by the direct condensation at high pressures (up to 1500 MPa) of piperonal (V) with 1-nitropropane (VI). The structure of (VII) was confirmed by direct synthesis from pyrocatechol (X). The amine (VIII) was obtained in three steps from (VII). This synthesis of (VIII) is shorter than that previously reported.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 829–832, April, 1990.     

Halogenated arenes in the Duff reaction at high pressures

The reaction of fluorobenzene with urotropine in trifluoroacetic acid (TFAA) at high pressures and temperatures affords predominantly fluorobenzaldehydes andN-(fluorophenylmethyl)trifluoroacetamides. The yields of these products depend considerably on the reaction conditions. The rates of their formation have the maximum values at the momemt of the phase transition (PT) of TFAA. A new efficient cyclic (dynamic) regime is proposed for the synthesis at high pressures. The regime involves periodically occurring PT of the solvent. The change in the relative rate of product formation with the degree of fluorobenzene conversion is wave-like.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 319–323, February, 1995.     

Generalized criterion of solvent polarity as a tool for control of chromatographic process

The generalized (reductive) criterion of solvent polarity was obtained by the method of multiparametric optimization of the Snyder index P", Hildebrand parameter _T , permittivity _r , and solvatochromism parameter E _T (30). Possibilities of employing this criterion for estimation of the elution power of normal and reversed mobile phases used in high-performance liquid chromatography were considered.     

Synthesis of condensed pregnano[17,16-<Emphasis Type="Italic">d</Emphasis>]triazolines under high pressure

Condensed pregnano[17,16-d]triazolines were produced in 1,3-dipolar cycloaddition of 16-dehydropregnenolone acetate with organic azides at 10 kbar. The structure of the synthesized compounds was determined by using two-dimensional NMR spectroscopy (¹H—¹H COSY, NOESY, HSQC, and HMBC).     

Formation of 1,2-oxazine derivatives: A novel type of reaction between 2-aminooxazoles and maleic acid imide

N,N-Disubstituted 2-aminooxazoles in acetic acid at 20°C undergo addition of maleinimide, converting to alkylidene succinimides or 1,2-oxazine derivatives.N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913; e-mail: zhulin@cacr.ioc.ac.ru. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1128–1131, August, 2000.     

13C and1H NMR spectra of substituted dihydropyrroles prepared by the reaction of 2-aminooxazoles and maleimide

Substituted dihydropyrroles were characterized by¹³C and¹H NMR spectra. The spectral patterns of these compounds and reversible hydrogen—deuterium exchange are discussed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 697–700, April, 2000.     

Products from heterodiene synthesis and 1,3-cycloaddition in the reaction of N,N-disubstituted 2-aminooxazoles with maleimide

N,N-Disubstituted 2-aminooxazoles react with maleimide in two directions: heterodiene synthesis with the formation of imides of 2-aminopyridine-3,4-dicarboxylic acids and/or 1,3-cycloaddition, forming imides of 2-amino-5-acyl-¹-pyrrolidine-3,4-dicarboxylic acids.     

Synthesis and Structure of 5-Indolyl-6-thienyl-1,2,4-triazines

Acylation of indole and 2,5-dimethylthiophene with 2-(3-indolyl)-2-oxoacetyl chloride afforded the corresponding diketones. 1-(2,5-Dimethyl-3-thienyl)-2-(3-indolyl)ethanedione reacted with thiosemicarbazide under atmosperic and elevated pressure to give 6-(2,5-dimethyl-3-thienyl)-5-(3-indolyl)-2,3-dihydro-1,2,4-triazine-3-thione whose structure was studied in detail by the X-ray diffraction method. Reactions of 6-(2,5-dimethyl-3-thienyl)-5-(3-indolyl)-2,3-dihydro-1,2,4-triazine-3-thione with amines and hydrazine resulted in formation of fused triazolo- and tetrazolotriazines.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 6, 2005, pp. 895–902.Original Russian Text Copyright © 2005 by Krayushkin, Yarovenko, Sedishev, Zavarzin, Vorontsova, Starikova.Dedicated to Full Member of the Russian Academy of Sciences V.I. Minkin on his Jubilee     

Henry condensation under high pressure 2. Effect of aromatic aldehyde type and pressure on the yield of ω-nitrostyrenes and secondary processes

Condensation of aromatic aldehydes (I)-(XX) with EtNO₂ and n-PrNO₂ in AcOH in the presence of AcONH₄ or i-BuNH₂ gives primarily-nitrostyrenes (Ia, b)-(XXa, b) and small quantities of nitriles (Ic)-(XXc), oximes (Id)-(XXd), and ketones (Ie, f)-(XXe, f). The yields of (Ia, b)-(XXa, b) at P=1 atm are higher for acceptor substituents on the aromatic ring whereas at P=10 kbar, they are higher for donor substituents. High pressures suppress the formation of (Ic-f)-(XXc-f) and the Z-isomers of (Ia, b)-(XXa, b). The high pressure technique is especially useful in the preparation of donor-substituted (Ia, b)-(XXa, b) which are intermediates in the synthesis of the psychotropic -phenylethylamines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 426–433, February, 1991.     

Synthesis and Structure of 4-Indolyl-5-(thieno[3,2-<Emphasis Type="Italic">b</Emphasis>]pyrrol-6-yl)imidazoles

A procedure was proposed for regioselective acylation of methyl 2-methyl-4H-thieno[3,2-b]-pyrrole-5-carboxylate with 2-(3-indolyl)-2-oxoacetyl chloride. Reactions of the resulting methyl 6-[2-(3-indolyl)-1,2-dioxoethyl]-2-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylate with aromatic aldehydes and ammonium acetate in acetic acid afforded the corresponding methyl 6-[2-aryl-4-(3-indolyl)imidazol-5-yl]-2-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylates. The structure of methyl 6-[2-(4-chlorophenyl)-4-(3-indolyl)imidazol-5-yl]-2-methyl-4H-thieno[3,2-b]pyrrole-5-carboxylate was studied by X-ray analysis.