A FACILE SYNTHESIS OF 3-GLYCOSYL-5-SUBSTITUTED-2-ISOXAZOLES

The 1,3-dipolar cycloaddition reaction between a 2-deoxy-D-aldose oxime (D-gluco or D-ribo) and an alkyne as dipolarophile (phenylacetylene, 2-propyn-1-ol, 3-chloro-1-propyne, or 3-bromo-1-propyne) is described. The new 3-glycosyl-5-substituted-2-isoxazoles are characterized physically and spectroscopically.     

The polymerization of 3-chloro-1-propyne and 3-bromo-1-propyne with Mocl5 and WCL6 based initiators and the structure of the resulting polymers

The WCl₆ and MoCl₅ initiated polymerizations of 3-chloro-1-propyne and 3-bromo-1-propyne were performed in both halogenated and aliphatic non-nucleophilic and in aromatic nucleophilic solvents. The structure of the obtained polymers suggested that the polymerization reaction occurs in two steps. In both nucleophilic and non-nucleophilic solvents, the first step consists of the metathesis polymerization of 3-chloro(bromo)-1-propyne followed by electrophilic cis–trans isomerization leading to polymers containing trans-cisoidal allyl chloride or bromide structural units. When the polymerization is performed in non-nucleophilic solvents, in the second step an intramolecular electrophilic addition followed by elimination takes place. The resulting polymers contain a highly conjugated cyclopentadiene ladder structure. When the polymerization is performed in nucleophilic aromatic solvents, the intramolecular electrophilic addition competes with the electrophilic substitution of the solvent resulting in polymers containing high concentrations of arylpropenyl structural units. Subsequently, depending on the nucleophilicity of the polymerization solvent, the polymer structure contains structural units based on cyclopentadiene and/or arylpropenyl groups.     

Synthesis of homopropargyl alcohols via sonochemical Barbier-type reaction

A series of homopropargyl alcohols were synthesized from the reaction mixture of zinc powder, 1,2-diiodoethane, 3-bromo-1-propyne and aldehyde or ketone in anhydrous THF under ultrasound. The homopropargyl alcohols were obtained as the only product in all cases when aldehydes were reacted with 3-bromo-1-propyne under this sonochemical Barbier-type reaction condition. The homopropargyl alcohol was produced as the major product and the low contamination of allenyl alcohol was also obtained when ketone was used as substrate under the reaction condition.     

Acetylenchemie, 14. Mitt.: PTC-Umsetzung von 9(10H)-Acridinon mit 3-Chlor-3-phenyl-1-propin und 3-Brom-1-phenyl-1-propin

Summary Reaction of 9(10H)-acridinone (2) with 3-chloro-3-phenyl-1-propyne under PTC conditions affords 1-methyl-2-phenyl-6H-pyrrolo[3,2,1-de]acridin-6-one (1 b), 10-(2-chloro-1-methyl-2-phenyl-ethenyl)-9(10H)-acridinone (4), 10-(3-phenyl-1-propynyl)-9(10H)-acridinone (7), and 10-(4-methylene-2,3-diphenyl-2-cyclobuteneylidenemethyl)-9(10H)-acridinone (5). The structure of the last compound which crystallizes in the triclinic system with the space group , was confirmed by X-ray diffraction. Under the same conditions 10-(3-phenyl-2-propynyl)-9(10H)-acridinone (3) and 10-(3-phenyl-1-propynyl)-9(10H)-acridinone (6) were obtained from 9(10H)-acridinone (2) and 3-bromo-1-phenyl-1-propyne.

     

Chromatographic properties and polarity evaluation of poly(1-trimethylsilyl-1-propyne) and poly(1-phenyl-1-propyne)

The chromatographic properties of poly(1-trimethylsilyl-1-propyne) (PTMSP) and poly(1-phenyl-1-propyne) (PPP) were studied by gas chromatography using packed columns. The selectivity and efficiency of columns packed with PTMSP and PPP were compared to the data obtained for columns with other known adsorbents and stationary phases. The McReynolds and Rohrschneider constants, on the basis of which the polarity of the new phases was evaluated, were calculated. The results of the investigation of chromatographic properties allow PTMSP to be brought in line with the polymeric adsorbents Porapak Q, Porapak QS, and Chromosorb 106, while PPP, with the methyphenylsilicon phases SE-52 and OV-3.     

Chromatographic and adsorption properties of the mixed stationary phase poly(1-trimethylsilyl-1-propyne)/poly(1-phenyl-1-propyne)

Adsorption and chromatographic properties of the mixed stationary phase poly-(1-trimethylsilyl-1-propyne)/poly(1-phenyl-1-propyne) (PTMSP/PPP) composed as 97: 3 by weight have been investigated by methods of low-temperature nitrogen adsorption and gas chromatography on packed columns. The resultant phase has uniform mesoporous structure. The chromatographic properties of the mixed phase are significantly different from the properties of the original porous polymers PTMSP and PPP. The adsorbent obtained by modifying Chromosorb P NAW with a mixture of polymers provides the selective separation of chlorosubstituted, saturated, and aromatic hydrocarbons.     

Chemical modification of poly(vinyltrimethylsilane) and poly(1-trimethylsilyl-1-propyne) using highly reactive metallating systems

Poly(vinyltrimethylsilane) and poly(1-trimethylsilyl-1-propyne) are metallated using normal and secondary butyllithium chelate complexes with tetramethylethylenediamine and superbases based on complexes of normal and secondary butyllithium with potassium tert-pentoxide as metallating agents. Optimal conditions ensuring metallation of poly(vinyltrimethylsilane) and poly(1-trimethylsilyl-1-propyne) with a high yield without degradation of macrochains are determined. Poly(vinyltrimethylsilane) and poly(1-trimethylsilyl-1-propyne) are functionalized via reactions of metallated polymers with CO₂, trimethylsilyl chlorosulfone, diethyl disulfide, and ethylene oxide. COOH, SO₃H, OH, and thioester groups are introduced into poly(vinyltrimethylsilane), and SO₃H and COOH groups are incorporated into poly(1-trimethylsilyl-1-propyne). Upon introduction of carboxyl groups into poly(vinyltrimethylsilane), its hydrophilicity and permselectivity with respect to H₂O/N₂, H₂O/H₂, and H₂O/CH₄ pairs increase. The introduction of SO₃H groups into poly(1-trimethylsilyl-1-propyne) and poly(vinyltrimethylsilane) leads to the appearance of proton conductivity of these polymers.     

Copolymerization of 4-methyl-2-pentyne with 1-trimethylsilyl-1-propyne and 1-trimethylgermyl-1-propyne with Nb-containing catalysts

It has been shown that the copolymerization of 4-methyl-2-pentyne with 1-trimethylsilyl-1-propyne or 1-trimethylgermyl-1-propyne with the use of niobium pentachloride-based catalytic systems in the presence of Ph₃Bi, Et₃SiH, and Bu₄Sn as cocatalysts yields corresponding copolymers of various compositions. The technique of determining the composition of copolymers from their IR spectra has been developed. The reactivity ratios of the monomers have been estimated. It has been demonstrated that these values increase in a sequence 4-methyl-2-pentyne > 1-trimethylsilyl-1-propyne > 1-trimethylgermyl-1-propyne.     

Acetylenchemie 12. Mitt.: Weitere studien über die phasentransfer-katalysierte umsetzung des 9(10H)-acridinons mil alkinylhalogeniden

By the phase transfer catalyzed reaction of 9(10H)-acridinone with 1-bromo-2-propyne, 10-(2-propynyl)-9(10H)-acridinone is synthesized. As prototropic rearrangement products of this 10-(1,2-propadienyl)-9(10H)-acridinone and 10-(1-propynyl)-9(10H)-acridinone are obtained, Under the given conditins 1-bromo-2butyne leads to 10-(2-butynyl)-9(10H)-acridinone and 2-chloro-3-butyne leads to 10-(1-methyl-1,2-propddienyl)-9(10H)-acridinone, 10-(1-methyl-2-propynyl)-9(10H)-acridinone, 9-(1-methyl-2-propynyloxy)acridine and 10-[1-methyl-3-(3,4-dimethylphenyl-2-propynyl)]-9(10H)-acridinone. The formation of the products is experimentally confirmed and with published work compared.     

Phase equilibrium and rheology of poly(1-trimethylsilyl-1-propyne) solutions

The phase equilibrium and rheological properties of poly(1-trimethylsilyl-1-propyne) solutions obtained with tantalum catalysts are studied. For three polymers with different molecular masses, phase diagrams are determined in a number of solvents. From these diagrams, the Hansen solubility parameters of poly(1-trimethylsilyl-1-propyne) are calculated by the method proposed in this work. Dilute solutions of poly(1-trimethylsilyl-1-propyne) behave as Newtonian liquids, whereas the viscosity of viscoelastic concentrated systems decreases as the shear rate grows. The molecular and rheological characteristics of studied poly(1-trimethylsilyl-1-propyne) samples are compared with the samples prepared with NbCl₅ catalysts. Poly(1-trimethylsilyl-1-propyne) obtained with a catalytic system involving tantalum pentachloride is characterized by high intrinsic viscosity and solution viscosity compared to poly(1-trimethylsilyl-1-propyne) prepared with niobium catalyst. The difference in properties is due to the dissimilar ratios of cis and trans units in the samples.     

A Facile and Stereoselective Synthesis of Arylethers of Vicinal Bromohydrins by Mitsunobu Reaction

A straightforward, high yielding and stereoselective synthesis of 3,4-dihydro-4-aryloxy-3-bromo-2H-1-benzopyrans, compounds 8 and 9 by Mitsunobu coupling of the corresponding bromohydrins is reported.     

Silver-catalyzed one-pot synthesis of arylnaphthalene lactones

Arylnaphthalene lignan lactones are valuable natural products with promising anticancer and antiviral properties. In an effort to simplify their synthesis, we investigated a one-pot multicomponent coupling reaction between phenylacetylene, carbon dioxide, and 3-bromo-1-phenyl-1-propyne. After the corresponding 1,6-diyne was generated in situ, cyclization afforded the desired product. The level of regioselectivity was enhanced through the tuning of electronic properties. The use of cinnamyl bromide which led to the formation of a 1,6-enyne intermediate was also studied.     

Synthesis and properties of homo- and copolymers of trifluoropropyldimethylsilyl-1-propyne with trimethylsilyl-1-propyne

Homopolymerization of 1-(3,3,3-trifluoropropyldimethylsilyl)-1-propyne is investigated in the presence of catalysts based on tantalum (V) chloride and niobium (V) pentachloride with various cocatalysts. As a result of homopolymerization, an insoluble polymer is formed. It is established that the insolubility of the homopolymer is connected with the presence in the polymer of “pseudocrystalline” regions playing the role of physical links. Copolymerization of 1(3,3,3-trifluoropropyldimethylsilyl)-1-propyne and trimethylsilyl-1-propyne under the action of the TaCl₅-Ph₃Bi system is studied. The relative activity constants of monomers, whose ratio points to the formation tendency of copolymers enriched with trimethylsilyl-1-propyne at the early stages of polymerization, are estimated. It is shown that the structures and solubilities of the obtained copolymers depend on their compositions. Gas-transport and hydrophobic-hydrophilic properties for soluble samples are studied. Soluble copolymers have good film-forming properties, improved hydrophobicity, stability against hydrocarbons, and high levels of gas permeability: properties that make them promising materials for the separation of various liquids and gaseous water-organic media.     

1,2-双[2-甲基-5-(3,4-二氟苯基)噻吩-3-基]全氟环戊烯的合成

在冰浴条件下, 2-甲基噻吩(1)与液溴反应生成3,5-二溴-2-甲基噻吩(2); 在－78 ℃条件下, 硼酸三丁酯加入2, 得到2-甲基-3-溴-5-硼酸基噻吩(3); 3,4-二氟溴苯与3反应得到2-甲基-3-溴-5-(3,4-二氟苯基)噻吩(4); 在－78 ℃下全氟环戊烯与4反应, 得到一种新的二芳基乙烯类光致变色化合物1,2-双[2-甲基-5-(3,4-二氟苯基)噻吩-3-基]全氟环戊烯(DT-1). 用IR, NMR, MS和元素分析确定了化合物DT-1的结构, 并对该化合物的光致变色特性进行了初步研究.     

STEROIDAL 2-AMINO-1,3,4-THIADIAZINES AND AMINOTHIAZOLES

Abstract

The reaction of 16-bromo-17-ketones and 2-bromo-3-ketones reacted readily-upon heating for short periods of time with thiosemicarbazide in isopropanol in a 1:2 ratio to give 2-amino-1,3,4-thiadiazines. Extension of this reaction to 21-bromo-33-hydroxy-5-pregnen-20-one produced the corresponding thiadiazine.     

Copolymers of 1,2-disubstituted acetylenes containing trifluoropropyl groups synthesized in the presence of NbCl<Subscript>5</Subscript>-based catalyst systems: Structure and gas-transport behavior

Using a NbCl₅-based catalyst system, random copolymers of 1-(3,3,3-trifluoropropyldimethylsilyl)-1-propyne and 1-trimethylsilyl-1-propyne are synthesized in a wide range of comonomer contents. The dependences of gas-transport behavior on the composition and supramolecular organization of the copolymer are studied. Composition regions and conditions of preparing copolymers combining high permeability coefficients with resistance against nonpolar organic solvents are ascertained. The copolymers demonstrate a high selectivity in the separation of butane from a methane–butane mixture.     

Acetylenic α-aziridinylcarbinols in reactions with hydrazine and methyl-substituted hydrazines

It is shown that hydrazones of phenylpropiolaldehyde are formed in the reaction of an acetylenic -aziridinylcarbinol — 1-hydroxy-1-aziridinyl-3-phenyl-2-propyne — with hydrazine and methyl — and 1, 1-dimethylhydrazine. The reaction of this carbinol with sym-dimethylhydrazine leads to the formation of phenylacetylene and 1-formyl-1, 2-dimethylhydrazine,1-aziridinyl-1-hydrazino-3-phenyl-2-propyne, or 3, 6-diphenylethynyl-1,2,4,5-tetramethyltetrazine, depending on the reaction conditions. It was established that the reaction of 1-hydroxy-1-aziridinyl-3-phenyl-2-propyne and 1-hydroxy-1-(2-methylaziridinyl)-2-propyne with hydrazine and methyl-substituted hydrazines is realized through an intermediate step involving the decomposition of the acetylenic aziridinylcarbinols to an -alkynyl aldehyde and ziridine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 753–757, June, 1978.     

2-Bromo-3,4,4-trichlorobut-3-enoates of certain natural alcohols, phenols, and oximes of carbonyl compounds

Previously undescribed 2-bromo-3,4,4-trichlorobut-3-enoates 1b-23b were synthesized in 84–91% yield from natural alcohols including terpenes and steroids, plant phenols, and oximes of natural carbonyl compounds 1a-23a by reaction of 2-bromo-3,4,4-trichlorobut-3-enoyl chloride in the presence of pyridine. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 212–215, May–June, 2006.     

Reactions of Cyanothioacetamide: Synthesis of Several New Thioxohydro-pyridine-3-carbonitrile and Thieno[2,3-b]pyridine Derivatives

Cyanothioacetamide (f 1) reacted with α,β -unsaturated carbonyl compounds 2a–d to afford thioxohydropyridine-3-carbonitriles 5a–d, which were used as the starting materials for the preparation of several thienopyridines via their reactions with active halogen-containing compounds, e.g., 2-bromo-1-phenylethanone (7a), 2-bromo-1-p-tolyl-ethanone (7b), chloroacetone (10a), α -chloroacetylacetone (10b), and chloroacetic acid ethyl ester (13). The structure of the newly synthesized heterocyclic compounds were established based on the data of elemental analyses, IR, ¹ H NMR, and mass spectra.     

Natural product chemistry,Part 132: Synthesis and oxidative cyclisation of 1,3-dihydroxy-10-methyl-4-(3-methylbut-2-enyl)-9(10H)-acridinone (glycocitrine-II)

Summary Reaction of 1,3-dihydroxy-10-methyl-9(10H)-acridinone (1) and 1-bromo-3-methylbut-2-ene (mol. ratio 1:1) in tetrahydrofuran at 20°C in the presence of alumina gave prenylacidinones2 (glycocitrine-II) and8 and the diprenylacridinone9; with an excess of 1-bromo-3-methylbut-2-ene, the prenyldihydropyranoacridinones12 and13 were formed. Oxidation of glycocitrine-II (2) withm-chloroperbenzoic acid furnished the furanoacridinone5 and the pyranoacridinone6; dehydration of the latter compound gave noracronycine (10).(the late)