Studies in the area of 2,3′-biquinolyl. 1. Arylation and hetarylation of 2,3′-biquinolyl dianion

The 2,3-biquinolyl dianion, when reacting with aryl- and hetaryl halides, forms arylation products at the 4 position, and treatment of these products with alkyl halides or water yields 1-alkyl-4-aryl-1,4-dihydro-2,3-biquinolyls or 4-aryl-1,4-dihydro-2,3-biquinolyls, respectively. Oxidation of the latter yields 4-aryl-2,3-biquinolyls. The cation dependence of the arylation reaction is demonstrated.Stavropol' State University, Stavropol' 355009. Russian Chemical Engineering University, Moscow 125190. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1094–1099, August, 1997.     

Thermal degradation of bromine-containing polymers. Part 9—Copolymers of 2,3-dibromopropyl methacrylate and 2,3-dibromopropyl acrylate with styrene

The products of the thermal degradation of copolymers of styrene (S) with 2,3-dibromopropyl methacrylate (2,3-DBPM) and 2,3-dibromopropyl acrylate (2,3-DBPA) have been analysed quantitatively using thermal analysis, infra-red spectroscopy, mass spectrometry and gas-liquid chromatography. The products are generally similar to those which result from the degradation of the two homopolymers and no significant interaction occurs between the two types of units in the polymer chains. The only abnormal feature is the fact that the yield of 2,3-DBPA increases as the 2,3-DBPA content of copolymers of 2,3-DBPA and S decreases but this is consistent with previous observations in related copolymer systems.     

Investigations in the region of 2,3′-biquinolyl 4. Alkylation of the dianion of 2,3′-biquinolyl

With alkyl chlorides and alkyl phenyl ethers the dianion of 2,3-biquinolyl forms the products from alkylation at position 4. Their treatment with alkyl halides or water gives 1, 4-dialkyl-1, 4-dihydro-2,3-biquinolyls or 4-alkyl-1,4-dihydro-2,3-biquinolyls respectively.For communication 3, see [1].Stavropol State University, Stavropol, Russia 355009. Russian Chemical Technology University, Moscow 125190. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1214–1217, September, 1998.     

Investigations of 2,3′-biquinolyl. 9. Reaction of 1′,4′-dihydro-2,3′-biquinolyl with organolithium compounds

The 1,4-dihydro-2,3-biquinolyl reacts with organolithium compounds to form the mixture of 4-R-1,4-dihydro-2,3-biquinolyls and 2-R-1,2-dihydro-2,3-biquinolyls in the ratio analogous to the conversion in the series of 2,3-biquinolyl. The utilization of the complex, the organolithium compound-TMEDA, in this process leads, after treatment of the reaction mixture with water, exclusively to 2-R-1,2-dihydro-2,3-biquinolyls. Treatment with methyl iodide leads to 1-methyl-2-R-1,2-dihydro-2,3-biquinolyls.     

Synthesis and protonation of 2,3′-biquinolyl dianions

It has been shown that the reaction of 2, 3-biquinolyls with an excess of lithium in tetrahydrofuran leads to the formation of dianions, treatment of which with water or D₂O gives 1, 4-dihydro-2, 3-biquinolyls or their 4-D derivatives in good yield. Oxidation of the latter leads to 4-D-2,3-biquinolyl. The reduction of 2, 3-biquinolyl has been studied.Stavropol State University, Stavropol 355009. Rostov State University, Rostov-on-Don 344090. Russian University of Chemical Technology, Moscow 125190. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1391–1394, October, 1996. Original article submitted September 10, 1996.     

Dramatic Solvent Effect in the Reduction of 2,3—Allenoic Acid Esters.A Simple Synthesis of 2,3—Allenols from 2,3—Allenoates

2，3－Allenols were prepared conveniently from the reduction reaction of 2,3-allenoates with DIBAL-H(Diisobutylaluminum hydride) in toluene.A dramatic solvent effect was observed for this reaction.     

Enzymatic dissymmetrization of meso-2,3-dimethylbutane-1,4-diol and its diacetate. Synthesis of scalemic (–)-lasiol

Acylation of meso-2,3-dimethylbutane-1,4-diol with vinyl acetate in the presence of porcine pancreatic lipase (PPL) leads to the dextrorotatory monoacetate of the above diol with enatiomeric excess (ee) 58—64%. Absolute configuration of this scalemic specimen was determined by its sequential transformation to levorotatory lasiol, a metabolite of the Lasius ants. Partial hydrolysis of the corresponding meso-diacetate, mediated by PPL or by the Pseudomonas sp. lipase affords the monoacetate of opposite configuration with ee 72—86%, a formal intermediate in the synthesis of (3S,4R)-faranal. Other microbial lipases used are distinctive in low chemoselectivity.     

Synthesis and Structural Characterization of 2,3-Bis（hydroxymethyl）-2,3-dinitro-1,4-butanediol

2,3-Bis(hydroxymethyl)-2,3-dinitro-1,4-butanediol(C6H12N2O8) was synthesized by condensation,cyclization,oxidative dimerization and deketalization of nitromethane with a total yield of 42.4%.The structure of the title compound was characterized by 1H NMR,13C NMR,FT-IR,elementary analysis,and X-ray single-crystal diffraction analysis,which reveals that the title compound crystallizes in triclinic,space group P with a = 0.6324(2),b = 0.6454(3),c = 0.7062(3) nm,α= 111.550(4),β= 95.505(4),γ= 113.395(4)°,V = 0.23595(16) nm3,Z = 1,Mr = 240.18,Dc = 1.690 g·cm-3,μ = 0.159 mm-1,F(000) = 126,R = 0.0304 and wR = 0.0907.     

Reaction of β-Cyclodextrin with N-2,3-Epoxypropylphthalimide. Preparation, Characterisation and Study of a New Substituted Cycloheptaamylose. Effects on the Water Solubility of Drugs

The reaction of -cyclodextrinwith N-2,3-epoxypropylphthalimide yielded a set of newamorphous host compounds with high solubility whichwas transmitted to the corresponding host-guestcomplexes. The structure was determined by comparing the 1H- and 13C-NMR spectra with those of theparent compound, the degree of substitution by integration of the corresponding NMR signals, and C, H,and N elemental analysis.     

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.     

Investigations in the region of 2,3′-biquinoline. 3. Synthesis of 2′-alkyl(aryl)-1′,2′-dihydro-2,3′-biquinolines and 2′-alkyl(aryl)-2,3′-biquinolines

A method was developed for the synthesis of 2-alkyl(aryl)-1,2-dihydro-2,3-biquinolines, based on the addition of organolithium compounds to 2,3-biquinoline in the presence of tetramethylethylenediamine. Their oxidation with manganese dioxide led to 2-alkyl(aryl)-2,3-biquinolines.For Communication 2, see [1].Stavropol State University, Stavropol 355009, Russia. Russian Chemical-Technology University, Moscow 125190. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 350–354, March, 1998.     

Syntheses of Methyl 2,3-di-O-Glycyl-α-D-glucopyranoside and 4,6-di-O-Glycyl-2,3-di-O-methyl-α-D-glucopyranoside,and Removal of Aminoacyl Groups from Sugar Moieties

Abstract

To confirm the potential usefulness of amino acid residues as protecting groups for sugar hydroxyls, methyl 2,3-di-O-glycyl-α-D-glucopyranoside (5) and methyl 4,6-di-O-glycyl-2,3-di-O-methyl-α-D-gluco-pyranoside (7) were synthesized as reference compounds. Conditions were then established for the removal of these aminoacyl groups from the sugar molecules. The reference compounds were easily prepared by condensation of methyl α-D-glucopyranoside derivatives with N-protected glycine in the presence of dicyclohexyl-carbodiimide (DCC). The aminoacyl groups were removed by alkaline treatment, as were conventional acyl groups and also with ease by enzymatic hydrolysis using Pronase E. Conventional ester and ether protecting groups are not removed by such enzymatic treatment. Removal of aminoacyl group from sugar moieties on a practical scale is also described.     

Synthesis and Structure of 2,3-Tetra-Methylene-5,6-Trimethylene-4-Pyrone

Weattemptedtosynthesizecompound(I)bythtereactionofadipylchloridewithcyclohexanonepiperidineenamineI'1-However,weobtainedinsteadthederivativeofa4-pyrone(U)whichmaybepossiblyapotentialmedicinef[2.3]EXPERIMENTALToastirredaolutioncontainingcyclohexanonepiperidineenamine,triethylamine'andchloroform,adipy1chloridedissolvedinchloroformwasaddeddropwiseatroomtemperature.Themixturewasrefluxedfor1h,cooledandhydrolyzedwithhydrochloricacidforanother1h.Theorganiclayerwasseparated,wasbedwithwater,drie…     

Vibronic spectra and normal coordinate analysis of substituted anilines—I. 2,3-, 2,4-, and 2,5-dimethylanilines

Vibronic spectra of 2,3-, 2,4-, and 2,5-dimethylanilines (DMA) have been recorded in the vapor phase and analysed primarily for ascertaining the frequencies of certain low lying fundamentals (< 1000 cm⁻¹) which were observed earlier in infrared and Raman spectra with rather poor intensities. In most cases, the investigation of vibronic spectra has supported the data observed in infrared and Raman spectra. However, a new frequency has been observed at ∼120 cm⁻¹ in each molecule and has been assigned to the CNH₂ out-of-plane wag. A detailed analysis of the vibronic spectra of these three molecules revealed that an interaction-induced blue-shift of nearly 1700 cm⁻¹ is caused in the (0, 0) band of all the three DMAs due to an electrostatic interaction between the NH₂ and CH₃ groups.The normal coordinate analyses (NCA) of the above three molecules have been carried out using a general valence force field (GVFF) with 21 principal and 30 interaction force constants, assuming an averaged structure, a planar geometry, and a C_s symmetry in each case. The fundamental frequencies were mostly taken from an earlier work reported from this laboratory. Some frequencies were also picked up from the investigation of the vibronic spectra reported herein. The force field calculations were carried out using the least-squares iterative technique. During final calculations, all the 51 force constants were allowed to iterate simultaneously, which reproduced the 52 experimentally observed fundamentals out of the 54 (35a′+ 19a″) expected ones within an average error of ± 1.0% with a reasonable potential energy distribution (PED) among the various normal modes.     

Thermolysis and [3+2]‐Cycloaddition Reactions of 2,3‐Diferrocenyl‐ and 2,3,‐Diruthenocenylcyclopropenones

Abstract

2,3‐Diferrocenyl‐ and 2,3‐diruthenocenylcyclopropenone undergo thermolysis at ～180°C with opening of the small ring via ketenocarbenes. Intramolecular transformation of the latter occurs with elimination of CO to yield dimetallocenylacetylenes. Alternatively, they enter into 1,3‐dipolar cycloaddition reactions with C≡C or C?C multiple bonds to give cyclopentadienone or cyclopentenone derivatives, respectively.     

Improved One-pot Synthesis of 4,6-Dihydroxyisophthalic Acid and 2,3-Dihydroxyterephthalic Acid

An improved method for the large-scale preparation of 4,6-dihydroxyisophthalic acid and 2,3-dihydroxyterephthalic acid has been developed.Compared to the previous procedures,this new process-requires much lower CO2 pressure of 0.3 Mpa and shorter reaction time.thus providing a convenient access for large-scale synthesis.The yield is high （93% and 65%,respectively）, and the oxidation of phenol is nearly inhibited,neither decolorization nor further chromatographic purification is required.     

Thermal degradation of bromine-containing polymers: Part 10—Copolymers of 2,3-dibromopropyl methacrylate and 2,3-dibromopropyl acrylate with methyl acrylate

The products of the thermal degradation of copolymers of methyl acrylate (MA) with 2,3-dibromopropyl methacrylate (2,3-DBPM) and 2,3-dibromopropyl acrylate (2,3-DBPA) have been analysed quantitatively using thermal analysis, infra-red spectroscopy, mass spectrometry and gas-liquid chromatography. The dominant products from the first of these systems are 2,3-DBPM monomer and chain fragments reflecting the behaviours of the homopolymers of 2,3-DBPM and MA, respectively. The yield of methyl bromide is at a maximum when the proportion of interunit bonds between the two monomers is at a maximum. From the second system, the dominant products are methyl bromide and the chain fragment or cold ring fraction. The mechanisms by which these and the many other products are formed are discussed with reference to related systems which have been studied previously.     

Stereoselective synthesis of 2,3-diamino-2,3-dideoxy-β-D-mannopyranosyl uronates

With the aim to find an efficient synthetic procedure for the construction of 2,3-diamino-2,3-dideoxy-β-D-mannuronic acids, we evaluated three mannosyl donors: (S)-phenyl 4,6-di-O-acetyl-2,3-diazido mannopyranoside, (S)-phenyl 2,3-diazido-4,6-O-benzylidene mannopyranoside, and (S)-phenyl 2,3-diazido mannopyranosyl methyl uronate. The first two mannosylating agents are rather unselective or slightly α-selective in their condensation with three different acceptors. The mannuronic acid donor on the other hand reliably provides the desired β-mannosidic linkage. A mechanistic rationale is put forward to account for the different behavior of the three donor types. Suitably protected 2,3-diazido mannuronic acids were employed to construct the all-cis-linked tetrasaccharide repeating unit of the capsular polysaccharide of Bacillus stearothermophilus , featuring two 2,3-diacetamido-2,3-dideoxy-β-D-mannuronic acids.     

Investigations of 2,3′-biquinolyl. 7. Thiolation of 1-alkyl-3-(2-quinolyl)quinolinium halides

Thiolation of 1-alkyl-3-(2-quinolyl)quinolinium halides by a mixture of sulfur with KOH in DMF leads to formation of 1-alkyl-1,4-dihydro-2,3-biquinolyl-4-thiones, rearrangement of which in boiling ethylene glycol makes it possible to obtain 4-alkylthio-2,3-biquinolyls.