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 stereochemistry of chiral azetidin-2-ones and azetidine-2-thiones. 3. Stereodirected construction of theβ-lactam fragment of the thienamycin molecule

It has been shown possible to introduce an -hydroxyethyl group trans-stereospecifically into position 3 of 4-methyl-1-(-methyl-benzl)azetidin-2-one. The stereochemistry of the asymmetric centers C₍₃₎, C₍₃₎, and C₍₄₎ of the diastereoisomers of the 3--hydroxyethyl derivative obtained in larger amount and of the corresponding three adjacent chiral centers C₍₈₎, C₍₆₎, and C₍₅₎ in thienamycin are the same.For part 2 see [1].M. V. Lomonosov Moscow State University, Moscow, 119899. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 254–257, February, 1995. Original article submitted December 14, 1994.     

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.     

Living Cationic Polymerization of α-Methylstyrene. 2. Synthesis of Block and Random Copolymers with 2-Chloroethyl Vinyl Ether and End-Functionauzed Polymers†

Abstract

Both AB and BA block copolymers of α-methylstyrene (αMeSt) and 2-chloroethyl vinyl ether (CEVE) were synthesized by the sequential living cationic polymerization initiated with the HCl-CEVE adduct (1a)/SnBr₄ system in CH₂Cl₂ at -78°C. αMeSt-CEVE (AB) block copolymers with narrow molecular weight distributions ([Mbar]_w/[Mbar]_n ～ 1.15) were obtained when αMeSt was polymerized first, followed by addition of CEVE to the resulting αMeSt living polymer solution. The reverse order of monomer addition, from CEVE to αMeSt, also led to a BA-type block copolymer. In the polymerization of a mixture of the two monomers, almost random copolymers were obtained. Living polymerizations of αMeSt were also induced with functional initiating systems, HCl-functionalized vinyl ether adducts (1b-1d)/SnBr₄, to give end-function-alized poly(αMeSt)s with a methacrylate, an acetate, or a phthalimide terminal.     

Metallation of benzyl selenides and of α-aryl selenoacetals. Scope and limitations.

α-Metallo benzylselenides and α-metallo selenoacetals derived from aromatic aldehydes have been conveniently prepared by metallation of the corresponding carbon acids. KDA in THF proved among the various basic systems tested, the most efficient.α-Metallo benzylselenides and α-metallo selenoacetals derived from aromatic aldehydes have been conveniently prepared by metallation with KDA of the corresponding carbon acids. These reactions have been used for the synthesis of arylalkanes, including those bearing a trialkylated benzylic carbon, from aromatic aldehydes.     

Copolymers from α-Pinene. 2. Cationic Copolymerization of Styrene and α-Pinene

A study of the copolymerization of α-pinene and styrene has been carried out at 10°C using anhydrous AlCl₃ as the initiator. It is found that styrene forms copolymer with α-pinene at all mono-meric ratios. A copolymer of 2320–3080 molecular weight is obtained. The softening range of the copolymer is 82 to 85°C. The copolymers are of commercial value.     

Synthesis and properties of furan derivatives. 3. Synthesis of 1,2-disubstituted δ2-imidazolines containing furfuryl and tetrahydrofurfuryl groups

The condensation of N-furfuryl- and N-tetrahydrofurfurylethylenediamines with hydrochloride salts of iminoesters of carboxylic acids gives 1,2-disubstituted ²-imidazolines containing furfuryl or tetrahydrofurfuryl groups at N¹.For communication 2, see [1]Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1312–1315, October, 1992.     

Condensation reactions of α-lithio-imidazolines: Preparation and conjugate additions of 2-alkenyl-2-imidazolines.

Whereas 1-benzyl-2-lithiomethyl-2-imidazoline undergoes reversible 1,2-addition to aldehydes and ketones, a derived phosphonate salt affords the condensation products, 2-(1-alkenyl)-2-imidazolines; the latter undergo conjugate addition with carbon nucleophiles.     

Infrared spectroscopy and modeling of co-crystalline CO2·C2H2 aerosol particles. I. The formation and decomposition of co-crystalline CO2·C2H2 aerosol particles

Aerosol particles composed of co-crystalline CO(2)·C(2)H(2) were generated in a bath gas cooling cell at cryogenic temperatures and investigated with infrared spectroscopy between 600 and 4000 cm(-1). Similar to results obtained for thin films of the co-crystal [T. E. Gough and T. E. Rowat, J. Chem. Phys. 109, 6809 (1998)], this phase was found to be metastable and decomposed into pure CO(2) and pure C(2)H(2). These decomposed aerosols were characterized through (i) a comparison to experimentally prepared aerosols of mixed CO(2) and C(2)H(2) of known architectures and (ii) the modeling of infrared spectra. A likely architecture after decomposition are C(2)H(2)-CO(2) core-shell particles with a disk-like shape. The co-crystalline CO(2)·C(2)H(2) aerosols prior to decomposition are modeled and analyzed in detail in the subsequent paper (Part II).     

Infrared spectroscopy and modeling of co-crystalline CO2·C2H2 aerosol particles. II. The structure and shape of co-crystalline CO2·C2H2 aerosol particles

Infrared absorption spectra of co-crystalline CO(2)·C(2)H(2) aerosol particles were modeled using a combination of two methods. Density functional theory was used to model several bulk CO(2)·C(2)H(2) co-crystal structures and to calculate their lattice energies and frequency-dependent dielectric tensors. This was necessary as there currently exists no crystallographic or refractive index data on co-crystalline CO(2)·C(2)H(2)due to its metastability. The discrete dipole approximation was then used to calculate infrared absorption spectra of different model particles using the dielectric tensors calculated using density functional theory. Results from these simulations were compared to the experimental spectrum of co-crystalline CO(2)·C(2)H(2) aerosol particles. The aerosol particles after the decomposition of the co-crystalline phase were studied in Part I.     

Rearrangement of 1-oxa-2-azoles. 5. Synthesis and rearrangement of α-oximodimethyl-hydrazones of 1,2,4-oxadiazolyl-3-glyoxal

The acid halides of 1,2,4-oxadiazol-3-carbohydroxamic acids react with formaldehyde dimethylhydrazone to give the corresponding -oximohydrazones, which with hydrochloric acid rearrange to yield the dimethylhydrazone of 3-amino-4-formylfurazane. In the absence of an acid catalyst, the 5-trifluoromethyl derivative undergoes a rearrangement to give 1-dimethylamino-4-nitroso-3-trifluoroacetamidopyrazole.For Communication 4, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 976–978, July, 1991.     

Reaction of 2-chloromethylbenzimidazoles with acetylacetone and benzoylacetone. Basic breakdown ofβ-diketones

Base treatment of the products of alkylation of-diketones by 2-chloromethylbenzimidazole under phase transfer catalysis (PTC) conditions causes loss of the acetyl group and formation of methylethyl- or ethylphenyl ketones.Rostov State University, Rostov-on Don 344090. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1067–1071, August, 1996. Original article submitted March 25, 1996.     

Synthesis and properties of furan derivatives. 1. Synthesis of 3,5-disubstituted Δ2-isoxazolines containing furfuryl fragments

3,5-Disubstituted ²-isoxazolines containing furan fragments have been synthesized by 1,3-dipolar cycloaddition reactions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 449–452, April, 1991.     

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.     

Acetals of lactams and acid amides. 73. Synthesis and some properties of derivatives of 6-nitro-γ-carboline

We have developed two synthesis routes for 4-amino derivatives of 6-nitro--carbolines: 1) consecutive conversion of 1,2-dimethyl-3-formyl-5-nitroindole to the 3-cyano derivative, condensation of the latter with DMF diethyl acetal, and cyclization of the enamine formed in this case with ammonia and benzylamine; 2) N-oxidation of 9-substituted 6-nitro--carbolines, transformation of N-oxides to the corresponding -carbolin-4-ones, from which the target compounds are obtained through the 4-chloro derivatives.For Communication 72, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 502–505, April, 1992.     

Gas-Phase reactions of NO2− with nitrobenzenes and quinones. Electron transfer,clusters and formation of phenoxide and quinoxide negative ions. Use of NO2 as a negative ion chemical ionization reagent

Negative-ion/molecule reactions in systems containing methane as the major gas (∼ 4 torr), with NO₂ and compounds A at mtorr pressures were studied in a pulsed electron, high pressure mass spectrometer. The compounds A were substituted nitrobenzenes and quinones. All these A compounds have positive electron affinities. Three types of reactions were observed and examined. (1) Electron transfer: A⁻ + NO₂ = A + NO₂⁻. The exothermic electron transfer reactions proceeded with ADO collision rates for exothermicities from 30 to ∼ 10 kcal mol⁻¹. Lower exothermicities led to low collision yields. (2) Adduct formation: NO₂⁻ + A = NO₂⁻·A. The equilibria for adduct formation were determined. Stable adducts are formed when A has hydrogens with partial protic character. The stability of the adducts NO₂⁻·A increased with increase in the electron affinity of A, when A was a substituted nitrobenzene. Substituents that increase the electron affinity of nitrobenzene are electron-withdrawing groups which also increase the protic character of the hydrogens involved in bonding in NO₂⁻·A. (3) Some of the compounds A were converted to phenoxy negative ions on reaction with NO₂⁻. For example, para-dinitrobenzene leads to formation of the para-nitrophenoxide negative ion. The oxy-negative-ion-forming reaction can be isomer specific. The utility of reaction types (1)–(3) is examined from the standpoint of negative ion chemical ionization where the reagent gas is NO₂ in methane and the reagent ion is NO₂⁻.     

Synthesis and characterization of diblock copolymer of butadiene and 2-ethyl-2-oxazoline

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Optically active cyclopropanols from the enzymatic resolution of dimethyl α-alkylsuccinates. Synthesis of chiral 2-vinylcyclobutanones and cyclohexenones.

(+)-(R) [or (-)-(S)] dimethyl α-methylsuccinates, obtained by the enantioselective hydrolysis of the racemic diester by porcine pancreatic lipase, undergo acyloin cyclization followed by stereoselective ring contraction to provide 1-alkenylcyclopropanols with high enantiomeric excesses.