Hydrocarbomethoxylation of C5-C9 olefins with formic acid and methanol under conditions of catalysis with phosphoric acid

Conclusions The methyl esters of branched carboxylic acids containing quaternary and tertiary C atoms in the-position, together with a small amount of the corresponding carboxylic acids, are formed during the hydrocarbomethoxylation of the straight-chain C₅-C₉ olefins at atmospheric pressure in the presence of concentrated H₃PO₄.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 454–456, February, 1973.     

Synthesis of the perfluoroacetyldiisopropylmethyl radical

A stable trifluoroacetylperfluorodiisopropylmethyl radical has been prepared by interaction of the (-fluorosulfonyloxytetrafluoroethyl)perfluorodiisopropylmethyl radical with anhydrous CsF. This reaction is the first example of a chemical transformation of a C-centered radical which is not resonance-stabilized with retention of the radical center.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 226–227, January, 1993.     

Synthesis of new unsaturated derivatives of functionally substituted 2-imino-2,5-dihydrofurans

5,5-Substituted 2-imino-4-methyl-2,5-dihydrofuran-3-carbonitriles reacted with aromatic aldehydes to give the corresponding 5,5-substituted 2-imino-4-(2-R-vinyl)-2,5-dihydrofuran-3-carbonitriles. The latter were converted into hydrochlorides which were hydrolyzed to 3-cyano-4-(2-R-vinyl)-2,5-dihydrofuran-2-ones whose condensation with malononitrile afforded dicyanomethylidene derivatives.     

Yerevan synchrotron injector electron beam transversal scan with vibrating wire scanner

We have developed extended-aperture (20 mm) vibrating wire scanner (VWS) for transversal scanning of electron beams with large transversal size. Test experiments were performed in open atmosphere on the 40 MeV electron beam of the Yerevan synchrotron injector with the 4–10 μA at outlet. A construction of VWS is elaborated for scanning beams with larger transversal size. This elaboration is a new precision tool for diagnostics of beams in accelerators, which may be successfully employed, because of universality of the used operation principle, for profiling of as well large-aperture proton and ion beams.     

Analysis of generation of terahertz radiation by nonlinear mixing of laser frequencies in GaAs crystal

Generation of terahertz (THz) radiation by nonlinear mixing of laser frequencies in GaAs crystal is considered for the case of free and guided propagation of THz waves. In the first case the strong diffraction of the THz radiation leads to the deviation from the known square-law growth of the generator power with increasing crystal length, In the second case the spatial divergence of the exciting laser beam results in the appearance of a maximum in the generated power dependence on the radius of the nonlinear waveguide. According to estimations, the optimal radius of the laser beam is 18 μm for the waveguide length of 6 mm and the maximal generated THz power is ～27 W at the laser beam power of 10 kW.     

Synthesis of Isatin and 5-Bromoisatin Derivatives

New N-derivatives of isatin were synthesized by treating ethyl chloroacetate, N-(2-chloroethyl)morpholine, and 1,4-di(chloromethyl)benzene with isatin sodium salt. N-Derivatives of isatin and 5-bromoisatin were also prepared by Mannich reaction.     

Reactions of aromatic dithiols with diethyl 2-alkyl-2-(oxiran-2-ylmethyl)malonates

New sulfur-containing butano-4-lactones were synthesized by reaction of diethyl 2-alkyl-2-(oxiran-2-ylmethyl)malonates with biphenyl-4,4′-dithiol, (biphenyl-4,4′-diyl)dimethanethiol, and (2,4,6-trimethylbenzene-1,3-diyl)dimethanethiol. Opening of the oxirane ring in the initial ester followed the Krasuskii rule.     

Synthesis and some chemical transformations of novel functionalized 2-imino-2,5-dihydrofurans

Hitherto unknown functionalized 2-imino-3-(N-cyclohexylcarbamoyl)-2,5-dihydrofurans were synthesized by the reactions of tertiary α-hydroxy ketones with N-cyclohexyl(cyano-acetamide). Several reactions of thus synthesized compounds at the imino group were carried out.     

Homogeneous operators and homogeneous integral operators

We introduce and study in a general setting the concept of homogeneity of an operator and, in particular, the notion of homogeneity of an integral operator. In the latter case, homogeneous kernels of such operators are also studied. The concept of homogeneity is associated with transformations of a measure—measure dilations, which are most natural in the context of our general research scheme. For the study of integral operators, the notions of weak and strong homogeneity of the kernel are introduced. The weak case is proved to generate a homogeneous operator in the sense of our definition, while the stronger condition corresponds to the most relevant specific examples—classes of homogeneous integral operators on various metric spaces—and allows us to obtain an explicit general form for the kernels of such operators. The examples given in the article—various specific cases—illustrate general statements and results given in the paper and at the same time are of interest in their own way.