Two-fragment α-adrenolytics. 4. Synthesis of phosphorylated derivatives of 2-aryloxyethylamines and N-phenylpiperazine

The reactions of 3-chloropropylphosphonates, 3-chloropropylthiophosphonates, or 3-chloropropylphosphinates with 2-aryloxyethylamines or N-phenylpiperazine afford the corresponding 3-(2-aryloxyethylamino)propylphosphonates and -phosphinates or 3-(4-phenylpiperazin-1-yl)propylphosphonates and -phosphinates. The compounds obtained exhibit -adrenolytic and hypotensive activities, the latter being found to depend on the substituents at the P atom.     

Synthesis and properties of thiazole halohydrazones. 2. Interaction of 2-α-chlorobenzylidenehydrazino-4-ethoxy-carbonylthiazole with nucleophiles

In the interaction of 2--clzlorobenzylidenehydrazino-4-ethoxycarbonylthiazole with nucleophiles, two competing reactions take place. 1) nucleophilic replacement of the chlorine atom to form the corresponding substitution product; 2) elimination of a hydrogen chloride molecule, concluding in cyclization of the intermediate nitrilimine to form 3 phenyl-5-ethoxycarbonylthiazolo(2, 3-c]-1, 2, 4-triazole. The direction taken by the interaction depends on the nature of the nucleophile and is determined primarily by the ratio of basicity and nucleophilicity of the agent.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, 256–259, February, 1994. Original article submitted December 30, 1993.     

2-Benzopyrylium salts. 41. Intramolecular transformations of 4-1′-dimers of α-unsubstituted 2-benzopyrylium salts

Recyclization reactions of 4-1-dimers of 2-benzopyrylium salts leading to naphthalene derivatives are described. A new variant of the intramolecular Cannizzaro rearrangement has been discovered.For communication 40, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 175–180, February, 1991.     

Studies on the Synthesis of Sesamin-Group Lignans Ⅷ. A Simplified Sythesis of 2-Aryl-4-phenyloxazoles and 2-Alkyl-4-phenyloxazoles

SubstitutedoxazolesareusefulstartingrnaterialsinthepeisOffurans'-2.InaformerpaPee.wehaverePOrtedamethodofpreParing2-arel49henyloxazoles1bophenaCylbenZOatederivatives2'(whichisreadilyavailableviarellbongaromahcadds3nd2hromoacetophoe'inalcohoI-watersoluhon)andabodcinboilingxyleneunderthecatalySsofBF3.(SChemeI)SchemeISincela-barebuildingblocksinournetvlydesignedSynthehcroutetOedn-grouPlignanS,wehopedthattbereportedpndurecollldbeadaptedonlargerscales.Whnwedidso,however,wefoundthatedonhmesw…     

Oxidation of β-Hydroxynitrosamines to β-Ketonitrosamines with KMnO4-Metal.SO4.XH2O in Non-Aqueous Media

The oxidation of β-hydroxynitrosamines to the corresponding β-ketonitrosamine is reported. The reactions carried out in benzene or dichloromethane using powdered KMnO₄-CuSO₄.5H₂O, or KMnO₄-MgSO₄.7H₂O. Work-up of the reaction and purification of the product requires only a filtration through magnesium sulfate and chromatography through a short Florisil column.     

Thermodynamics of the Dissociation of Carbonic Acid in Mixed Solvent.4. The System of NaHCO_3-Na_2CO_3-NaCl-Ethanol-Water

Theeffectofethanol-watermixtureontheseconddissociationconstantofcarbonicacidwasofinterestnotonlyforbiologistsbutalsoforchefestsandchemicalengineers,becauseitmayprovideusefulinformationinregardtotheidentificationofthenatureofthesesolute-solventinteractionpatternsinbinarysolventsystem"'.ThispaperreportStheseconddissociationconstantsofcarbonicacid,K,,atfivetemperaturesfrom278.15to318.15Kin5,15,25mass%ethanol-water"dxedsolventsdeterminedfrompreciseelnfmeasurementsincell(A)withoutliquidjunction:Pt…     

Synthesis,crystal structure of Gd(H2O)(C2O4)2 · NH4 and of La(C2O4)2 · NH4. Characterization of the Ln(H2O)(C2O4)2 · NH4 with Ln=Eu…Yb

Single crystals of two lanthanide complexes, presenting similar formula Ln(H₂O)_x(C₂O₄)₂ · NH₄ with Ln=La, x=0 and Ln=Gd, x=1, have been prepared, in closed system at 200 °C. The gadolinium complex is bi-dimensional. A layer is built by the packing of the basic unit, [Gd(C₂O₄)]₄. The gadolinium atoms are related only by bischelating oxalate ligands, the ammonium ion and the water molecule (bound to the gadolinium atom) are localized into the interlayer space. The lanthanum complex is tri-dimensional. The basic building unit remains approximately the same and the packing of these units form a layer. However, within these units, the lanthanum atoms are related by either an oxalate ligand or an edge. Moreover, an oxalate ligand assumes the connection between the layers. The ammonium ion is localized into two sets of intersecting channels. Pure phase of the gadolinium complex has been prepared at 100 °C and extended to some lanthanide elements, Eu…Yb. As the size of the lanthanide ionic radius is decreasing, it is noticeable that the a unit–cell constant follows an expansion pattern while the others two follow an usual contraction one. The thermal behavior of this family shows that the anhydrous compounds are obtained and that some water molecule is sorbed during the cooling. Thus, the anhydrous compounds present a relatively open-framework with some small micropores.     

Autoassembly of cage structures. 4. Stereochemistry of 2,5-di-tert-butyl-γ-butyrolactone-4-carboxy-s-(α)-phenylethylamide

The diastereoisomeric lactonamides (2a, b), obtained from the dilactone (1) and S-phenylethylamine, have been separated. X-ray crystallography shows that the high-melting isomer (2a) has theR-configuration at the chiral centers C² and C⁴, the enantiomeric conformation of the -lactone ring being of theS-type in thetwist form, intermediate between envelope ² E and semi-chair ₃ ² T. It is shown by molecular mechanics that the minimum steric energy of2a corresponds to a conformation of the heterocycle close to the envelope form₃E. Examination of van der Waals interactions shows that the calculated structure for2a is preferred. The reasons for the nonidentity of the forms of the -lactone ring of2a in the crystal and the free state are discussed. The crystal structure of2a is composed of two geometrically similar independent molecules associated along the axis by weak hydrogen bonds of two types, the energies of which have been estimated from the v_XH values, which are related by the expression v_XH=f(R_X...O), where X=N, O.For previous communication, see [1].N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1601–1611, July, 1992.     

Derivatives of heterocyclic α-iminocarboxylic acids. 4. Reduction of N-alkoxycarbonyl derivatives of α-iminocarboxylic acids

When N-methoxycarbonyl and N-benzoxycarbonyl derivatives of methyl esters of aziridine-2-carboxylic acid, L-proline, L-thioproline, and pipecolic acid interact with NaBH₄ in tert-butanol/methanol, the products of reduction of the C-methoxycarbonyl group of the original compounds are accompanied by bicyclic urethanes and oxazolidines. Reduction of N-maleates and N-fumarates of heterocyclic -iminocarboxylic acids leads to the formation of -hydroxymethyl-N-[4-(2-oxo-2,5-dihydrofuryl)] derivatives of pyrrolidine, piperidine, 1,3-thiazolidine, and 1,4-thiazan. In the latter case, 1-aza-2-hydroxymethyl-4-oxo-5-oxa-9-thiabicyclo [5.4.0]undecene-2 is also obtained. The N-maleates and fumarates of aziridine-2-carboxylic acid are reduced anomalously by sodium borohydride, forming 2-hydroxymethyl-2-(-hydroxyethyl)-3-oxa-1-azabicyclo[3.1.0]hexanes.For Communication 3 see [2].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1567–1573, November, 1993.     

Au-catalyzed cyclization of allenylsilanes. Regioselective conversion to 2-amino-4-silylmethylene γ-butyrolactone

The Au(I)-catalyzed cyclization of an allenylglycine, which possessed a silyl group attached to the opposite side of the allenic terminus, occurred at the allenic center to produce the 2-amino-4-silylmethylene-substituted γ-butyrolactone 2a in a highly regio- and stereoselective manner. The presence of a silyl group at the allenic terminus is crucial for the present 5-endo-dig γ-butyrolactonization.     

Chemical Modification of Kanamycin A. II. Nucleophilic Displacement Reactions of Kanamycin-A-4″-sulfonates

Abstract

Reactions of 2′,3′,4′,2″,6″-penta-O-acetyl-tetra-N-tert-butyloxycarbonyl-kanamycin-A-4″-brosylate (4b) or-4″-triflate (4c) with acetate, thiolacetate, azide, and fluoride, respectively, result in the formation of the corresponding derivatives of 4″-epi-kanamycin A (5a-d). While 4b invariably forms an elimination byproduct (9), the only side—reaction of 4c consists in a neighboring group attack with formation of a 3″-epi-4″-cyclic urethane (7). Removal of the protecting groups yields 4″-epi-(6a), 4″-thio-4″-epi-(6b), 4″-deoxy-4″-fluoro-4″-epi-(6d), 4″-azido-4″-deoxy-4″-epi-(6c), and after hydrogenation of the latter, 4″-amino-4″-deoxy-4″-epi-kanamycin A (6f).

Methyl 2,6-di-O-acetyl-3-amino-3-N-tert-butyloxycarbonyl-3-deoxy-4-O-triflyl-β-D-glucopyranoside (1b) served as a model to anticipate preparation, handling, and reactivity of 4c.     

4-hydroxy-2-quinolones. 149*. Synthesis,chemical transformations,and biological properties of β-N-acylhydrazides of 1-R-4-hydroxy-2-oxo-1,2-dihydro-quinoline-4-carboxylic acids

Two methods of preparation have been proposed and the synthesis has been effected of a large series of β-N-acylhydrazides of 1-R-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acids. The possibility of using various condensing agents for converting them into the corresponding 1,3,4-oxa-diazoloquinolines has been studied. Results are given of an investigation of the antitubercular activity of the synthesized compounds. * For Communication 148 see [1]. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1655–1663, November, 2008.     

Low-molecular-weight bioregulators 4. Synthesis of 2-isopropyl-2,5-dimethyl-2,3-dihydrofuran — The sex pheromone of the leather-winged sailorHylecoetus Dermestoides L.

A new four-stage method has been developed for obtaining racemic 2-isopropyl-2,5-dimethyl-2,3-dihydrofuran — the sex pheromone of the leather-winged sailorHylecoetus Dermestoides L.For Communication 3, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 468–471, April, 1992.     

Synthesis and properties of thiazole halohydrazones. 1. Synthesis and interaction of 2-α-chlorobenzylidenehydrazino-4-ethoxycar-bonyl-thiazole with triethylamine in the presence of dipolarophiles

In the interaction of 2--chlorobenzylidenehydrazino-4-ethoxycarbonylthiazole with triethylamine, a nitrilimine is formed as an intermediate that does not react with dipolarophiles, but rather undergoes intramolecular 1, 5-dipolar cyclization to form 3-phenyl-5-ethoxycarbonylthiazolo[2,3-c]-1,2,4-ttiazole.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, 253–255, February, 1994. Original article submitted November 30, 1993.     

The influence of medium on the stability of coordination compounds 4.The system In(tiron)~--NaClO_4-C_2H_5OH-H_2O

The stability constants of complex anion In(tiron)~-in mixed solvents of ethanol-water withweight percentages of ethanol being 0,5,15,25,35 and 50 have been measured spectrophotometricallyat 293 K,using NaClO_4 as supporting electrolyte with ionic strength ranging from 0.1 to 3.3mol·dm~(-3).The thermodynamic stability constants of In(tiron)~-in various mixed solvents have been obtained bya polynomial approximation equation based on Pitzer's theory.As a comparison,the traditionalDebye-Hückel equation has also been used to treat the same data.The results show that this polynomialapproximate method is obviously superior to the old one.It was discovered that there is a linear rela-tion between the thermodynamic stability constants of In(tiron)~-and the mole fraction of organiccomponent in mixed solvents or the reciprocal of dielectric constants of mixed solvents.The mediumeffect and the standard free energy of transfer,ΔG_(tr)~0,for the coordination reaction:In~(3+)+tiron~(4-)=In(tiron)~-,have also been discussed.     

Crystal Structure of 4, 5-trans-2-Amino-1, 3, 3-tricyano-4, 5-di (4-chlorophenyl)cyclopentene. Ethanol. Monohydrate

1mTRODUCT10NSincethetimeKaganhasdem0nstratedasimplepreparationofsamariumdiio-didefromsamariummetaland1,2-diiodoethanet1),SmI2hasbeenwidelyusedinsyntheticreactionst23.Thereactivityofsamariumdiiodidetowardsvariousnitrogen-containingcomP0undshasalreadybeenexamined.Thereare,toourknowledge,noliteratureexamplesforthereductionofcyanogrouptoproduceaminowiththisreagent.Inthispaper,wediscussedthecrystalstructureofthetitlecomP0undsyn-thesizedbythereactionofsamariumdii0didereagentwithp-chloroben-zyli…     

Studies on Agarofurans VIII. Synthesis of the Metabolites of 4-Butyl-a-agarofuran

Agarofurans have been found to be active on the nervous system in our institute. 4-Butyl-a-agarofuran 1 is a promising drug candidate. In order to explore the pharmacokinetics of 1, the metabolism of 1 in vitro was studied with liver microsomes from rats. Five metabolites were isolated and structures were identified as compounds 2-6. But the absolute configuration of 2,4,5 and the position of carbonyl in 3 could not be unambiguously determined. Further determination was limited by the smal…     

Reaction of aminoquinolines with unsaturated carboxylic acids. 2. Cyclization of N-quinolyl-β-alanines

The cyclization of N-(3-quinolyl)- and N-(6-quinolyl)--alanines was carried out to give uncondensed hexahydropyrimidine derivatives, while the cyclization of N-(5-quinolyl)- and N-(8-quinolyl)--alanines gave tetrahydrophenanthrolinone derivatives.Communication 1, see ref. [1].Kaunas Technological University, 3028 Kaunas, Lithuania, Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 653–657, May, 2000.     

Photocrosslinking of Silicones. Part XV. Cationic Photocrosslinking of α, ω, 4-Terminated Disiloxanes

Abstract

The photoinduced cationic crosslinking of α, ω-terminated disiloxanes (epoxy, vinyl ether, propenyl ether) has been investigated by means of Real-Time IR spectroscopy. A lipophilic iodonium salt and three lipophilic sulfonium salts were used as photoinitiator. The crosslinking rate is influenced by the type of α, ω-terminated disiloxane used and differed by a factor of more than 100 from the aliphatic epoxy to the vinyl ether derivatives. Moreover, the sulfonium salts were found to have a lower initiation efficiency than the lipophilic iodonium salt in the various systems studied. These results are in good agreement with the quantum yield of proton formation in a hexamethyldisiloxane/dimethoxyethane mixture. The final degree of conversion is larger with the ene derivatives than with the epoxy derivatives. The application of a kinetic method allows us to estimate the rate constant of the termination step (k_t and for the propenyl derivative the rate constant of the propagation step kp. The termination step can be described by means of a first order reaction. k_t was found to depend on the light intensity and the type of initiators used, whereas k_p is independent of the initiator used.