Synthesis and Some Biological Properties of Pyrrolo[1,2‐a]indoles

The procedures for the synthesis of substituted pyrrolo[1,2‐a]indoles and some of their biological properties are reviewed.     

Synthesis of Some 3-Substituted 1,2-Dihydroindoles

The reaction of 4-oxo-2-(2-oxo-1,2-dihydroindol-3-ylidene)hydrazone-1,3-thiazin-6-methyl carboxylate 2 with hydrazine hydrate in methanol gave 4-oxo-2-(2-oxo-1,2-dihydroindol-3-ylidene)hydrazone-1,3-thiazin-6-carbonylhydrazine 3. Furthermore, the reaction of 3 with carbon disulfide and then hydrazine hydrate afforded 3-[6-(4-amino-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)-4-oxo-1,3-thiazin-2-yl] hydrazone-1,3-dihydroindol-2-one 5. the latest reacted with DMAD to give {6-hydroxy-3-[4-oxo-2-(2-oxo-1,2-dihydroindol-3-ylidene)hydrazone-1,3-thiazin-6yl]-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-7-ylidene}methoxycarbonylmethylene 6.     

Synthesis and Antimicrobial Properties of Fluorinated 1,2-Aminopropanethiols

Reactions of 1,2-aminopropanethiols with methyl trifluoropyruvate were studied, and the antibacterial and fungicidal activity of the resulting trifluoromethyl derivatives as additives to lubricants was examined.     

The Synthesis and Some Chemical Properties of New 1,2:5,6-DI-O-Isopropylidene-α -D-Glucofuranose Hydrophosphoryl Derivatives

Methods for the synthesis of major monosaccharide hydrophosphoryl derivatives have been developed with the phosphorylation of 1,2:5,6-di-O-isopropylidene-α -D-glucofuranose (diacetoneglucose) as an example. The study of their chemical transformations has been launched.     

Structure,Synthesis, and Properties of Some Persubstituted 1,2-Dintroethanes. In Quest of Nitrocyclopropyl-Anion Derivatives

Attempts to deprotonate nitrocyclopropane led to solutions which showed strong ESR. signals (Fig. 1)and from which 1-nitro- l′-nitroso-bicyclopropyl ( 3 ) and 1,1′-dinitro-bicyclopropyl ( 2 ) were isolated. The activation energy for rotation about the central C, C-bond of 2 is estimated to be about 12 kcal/mol (¹ H-NMR. spectra in Fig. 2). In contrast, the oven-chain analogue 2,3-dimethyl-2,3-dinitrobutane ( 1 ) shows a methyl singlet down to ?70° C. Low-temperature X-ray analyses of 1, 2, 3 , and also of 1,1′-dinitro-bicyclobutyl ( 4 ) show that all four molecules have gauche-conformations but reveal striking structural differences between the openchain and the cyclic derivatives (Fig. 4–6): the central C, C-bond is long in 1 (1.575 Å), short in 2 (1.479 Å); the C, N-bonds are long in 1 (1.549 Å), short in 2 (1.488 Å); the orientation of the nitro groups is bisected in 2 and perpendicular in 1. The crystal structure of the nitro-nitroso compound 3 is isomorphous with that of the dinitro compound 2 and thus disordered (Fig. 15–16). The effect of the nitro group as π-electron acceptor on the molecular conformations and bond lengths is discussed. From analysis of the anisotropic vibrational parameters of 2 the root-mean-square librational amplitude of the nitro groups about their C, N-bonds is estimated to be about 5.8° at 95 K, corresponding to a rotational barrier of about 9 kcal/mol, i. e. the same order of magnitude as the NMR. estimate of about 12 kcal/mol for C, C-rotation.     

Synthesis with 1,2-Oxazines. II. Synthesis and Properties of 2,3-dimethyl-5,6-dihydro-4H-1,2-oxaziniumiodide

Preparation of 2,3-Dimethyl-5,6-dihydro-4H-1,2-oxaziniumiodide was achieved by N-alkylation of 3-methyl-5,6-dihydro-4H-1,2-oxazine. Reactions with C-nucleophiles led to the corresponding N-methyl-perhydro-1,2-oxazine derivatives. Reaction with sodium hydride in triglyme led to 3-methyl-4-aza-1,3-pentadiene.     

二茂钛苄氧基衍生物的合成及性质研究

Ｃｐ２ＴｉＣｌ２及（ＭｅＣｐ）２ＴｉＣｌ２在Ｅｔ３Ｎ或ＮａＮＨ２存在下与苄醇类化合物反应，高产率地合成了６个未见文献报道的二茂钛（Ⅳ）苄氧基衍生物，甲基二茂钛（Ⅳ）苄氧基化合物，经元素分析，ＨＮＭＲ和ＩＲ光谱确定了化合物的结构，并对其部分性质进行了讨论。     

Synthesis and Some Properties of Cerium Dioxide Hydrosols

Cerium dioxide hydrosols are synthesized by peptizing with nitric acid a precipitate obtained by hydrolyzing cerium(III) nitrate. The synthesized sols are stable with respect to aggregation in both acidic (pH 1.5–3.0) and alkaline media (pH 9.0–11.0). The mean hydrodynamic radius of particles is about 25 nm. The isoelectric point corresponds to pH 6.2. The phase composition of sol particles is determined by X-ray diffraction at pH of the dispersion medium ranging from 1.5 to 3.0. The sol coagulation thresholds are determined in the presence of sodium nitrate and sulfate, as well as of mixed magnesium salt at various pH values of the dispersion medium. Assumptions are made concerning the nature of the aggregative stability of sols.     

Synthesis and Antioxidant Properties of Novel 1,3,2-Oxazaphospholanes Incorporating 1,2-Dihydropyridines

Novel chiral 1,3,2-oxazaphospholane-2-sulfides incorporating a dihydropyridine ring have been synthesized via phosphorylation of 2-aminopyridinium salts, followed by in situ oxidation and cyclocondensation with 2-(alkylamino)ethanol. Cyclic organothiophosphates thus obtained have been screened for their antioxidant properties.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Synthesis and Hydrogenation of 1,2-1,4-1,2-Stereotriblock Polybutadienes and the Study of Their Properties

The effects of various polar modifiers, their concentration, and the polymerization temperature on the microstructure of poly-butadiene obtained during anionic polymerization using lithium α-methyl naphthalene as the bifunctional initiator were studied. 1,2-1,4-1,2-Stereotriblock polybutadiene was synthesized by polymerization in cyclohexane to a certain conversion and polymerization was completed in the presence of diethylene glycol dimethyl ether. The microstructure of the stereotriblock copolymer was characterized by IR and ¹H-NMR. GPC showed that the stereo-block polybutadiene has a narrow MWD. Two T_g's of the copolymer with higher molecular weight exist, as shown by dynamic mechanical test. The stereotriblock copolymer was hydrogenated using cobalt 2-ethyl hexanoate and triisobutyl aluminum as the catalyst. The hydrogenated product was shown to be a (butene-1-ethylene-butene-1) triblock copolymer which consists of more than 30% crystallinity and exhibits the behavior of a thermoplastic elastomer. The relationship between stress-strain properties arid the contents of the blocks was also studied.     

Synthesis and Complexation Properties of Some Novel Lariat-Crown Ethers

Summary.  Several new lariat-crown ethers bearing either bridged bisdioxine or tetraoxaadamantane units as chiral substituents are prepared by reacting the corresponding amino-crown ether derivatives with the dimeric α-oxoketene, the latter obtained by flash vacuum pyrolysis of a furan-2,3-dione precursor. Complexation properties towards differently charged metal ions are investigated by ¹H NMR titration to obtain complexation constants (K _c -values for potassium/sodium rhodanides: 480–1100 mol dm⁻³), as well as extraction experiments to explore the metal ion transportation abilities of the new lariat crown derivatives. In particular, a significantly increased ability to transport metal ions from water into chloroform was found with spherical tetraoxaadamantyl derivatives when compared with the free amino-benzocrown ethers. Corresponding author. E-mail: kollenz@kfunigraz.ac.at Received July 5, 2002; accepted July 19, 2002     

The Synthesis and Properties of Some Fluorinated Dialkyl Phosphoramidates

The synthesis and physical properties of the first fluorinated dialkyl phosphoramidates of structure (RCH 2 O) 2 P(O)NHCH 2 R F , where R = CH 3 , CF 3 or CCl 3 and R F = CF 3 or C 2 F 5 , are described. They were obtained by treatment of the respective dialkyl phosphorochloridates with trifluoroethylamine or pentafluoropropylamine in ether in the presence of triethylamine.     

Synthesis and Properties of Some New 1,3,2-Oxazaphospholane Derivatives

Abstract

A series of new 1,3,2-oxazaphospholane derivatives(I) have been synthesized by the reaction of P(NEt₂)₃ with RNHCH₂O₂OH at 80°C. When they were refluxed with sulfur in benzene, compounds II were obtained conveniently.     

1,3,4-恶二唑啉类化合物的合成及波谱性质

研究２－苯基－１,２,３－连三唑－４－甲醛芳酰腙（Ⅳ）和乙酰二茂铁芳酰腙（Ⅴ）分别在Ａｃ２Ｏ中的环化反应,制得１０种新的２,５－二取代基－３－乙酰基－１,３,４－恶二唑啉类化合物,并对其波谱性质进行了讨论。     

The Synthesis of Some Novel 1,2‐Dihydroisoquinoline Derivatives

Treatment of methyl 2‐aryl‐1,2,3,4‐tetrahydroisoquinoline‐3‐carboxylates 5 with N‐bromosuccinimide followed by heating in the presence of an acid catalyst resulted in the formation of the corresponding methyl 2‐aryl‐1,2‐dihydroisoquinoline‐3‐carboxylates 10 via an oxidation–dehydration sequence.     

Synthesis and Physical Properties of Sterically Congested Cycloalkenes, 1,2-Di-tert-butyl-3,3,5,5-tetramethylcyclopentene and 1,2-Di-tert-butyl-3,3,6,6-tetramethylcyclohexene

Two sterically congested cycloalkenes (9 and 10), congeners of tetra-tert-butylethylene, were synthesized and characterized. Oxidation of the bicyclic 1,3-dithietane 8 with dimethyldioxirane (DMD) gave the endo,endo-disulfoxide 13, thermal isomerization of which to the endo,exo-disulfoxide 15 followed by oxidation with DMD gave the trioxide 18. Heating 18 in refluxing 1,3-dimethyl-2-imidazolidinone furnished 1,2-di-tert-butyl-3,3,5,5-tetramethylcyclopentene (9) in 69% yield by a 2-fold extrusion process. The reaction of the 1,6-diketone dihydrazone 23 with Se(2)Cl(2) gave the selenadiazoline 34 and the 1,3-diselenetane 35. Heating 34 at 115-130 degrees C gave 1,2-di-tert-butyl-3,3,6,6-tetramethylcyclohexene (10), a "didehydro" derivative of tetra-tert-butylethylene, in 43% yield. The C=C bond in 10 is strained in degree comparable to those of most strained alkenes reported so far.     

Synthesis and Some Properties of Tungstophosphatozincates and Their Thermolysis Products

Russian Journal of General Chemistry - Tungstophosphatozincates with the Keggin anion structure Kt5[PW11O39Zn(H2O)]?nH2O, Kt = Rb+, Cs+, (CH3)4N+; (C2H5)4N+ were synthesized. Their...