Synthesis of 11,12,12a,13-tetrahydro-6H-indolo[1,2-b]-[2,4]benzodiazepines

Alkylation of 2,3,3-trimethyl- and 2,3,3,5-tetramethyl-3H-indoles with 2-bromomethylbenzonitrile gave 2-methylene-1-(2-cyanobenzyl)-2,3-dihydro-1H-indoles. When treated with lithium aluminum hydride the latter are cyclized to 11,12,12a,13-tetrahydro-6H-indolo[1,2-b][2,4]benzodiazepines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 815–817, June, 1990.     

[2+2]-Photocycloaddition von Cyclohexen an 2-Acetyl-5,5-dimethyl-1,3-cyclohexandion und 3-Acetyl-1,5,5-trimethyl-2,4-pyrrolidindion

Summary Irradiation of solutions of excess cyclohexene and 2-acetyl-5,5-dimethyl-1,3-cyclohexanedione (1), and 3-acetyl-1,5,5-trimethyl-2,4-pyrrolidinedione (4) results mainly in the formation of 1,5-diones2 and5. These originate from intermediate cycloadducts of cyclohexene and theexo-enols of the cyclic 1,3-diketones. The yields decrease with increasing polarity of the solvent. In solution2 and5 are in equilibrium with the cyclic hemiacetales3 and6.

     

Study of reaction of 2,3,3-trimethyl-3H-indole with haloacetic acid amides. Synthesis of 1,2,3,9a-tetrahydro-9H-imidazo[1,2-a]indol-2-ones

In the reaction of 2,3,3-trimethyl-3H-indole with -chloro- and -iodoacetamides, 1-carbamoylmethyl-2,3,3-trimethyl-3H-indolium salts are formed, which by the action of bases convert into imidazo[1,2-a]indol-2-one and 1-carbamoyl-2-methylene-2,3-dihydroindole. The latter compound can by cyclized into imidazo[1,2-a]indol-2-one by the action of acetic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 933–935, July, 1985.     

1,2,3,9a-Tetrahydro-9H-imidazo[1,2-a]indoles

When derivatives of 1,2,3,9a-tetrahydro-9H-imidazo[1,2-a]indol-2-one or 1-carbamoylmethyl-2-methylene-2,3-dihydroindole are reacted with lithium aluminum hydride, derivatives of 1,2,3,9a-tetrahydro-9H-imidazo[1,2-a]indole are formed. Under the same conditions 1-(N-phenylcarbamoylmethyl)-2-methylene-2,3-dihydroindole is not cyclized to an imidazo[1,2-a]indole. WHen treated with proton acids imidazo[1,2-a]indoles are converted to 3H-indolium salts. Opening of the imidazolidine ring is also found when imidazo[1,2-a]indole is acylated with benzoyl chloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 227–230, February, 1987.     

Reaction of 2-methylene-2,3-dihydroindoles with acrylamide

1,3-Dihydrospiro[2H-indolo-2,2-piperidine] derivatives were obtained by the reaction of 2-methylene-2,3-dihydro-1H-indole derivatives with acrylamide in proton-containing solvents. 2-(3-Carbamoylpropyl)-3H-indolium perchlorates were formed when the 1,3-dihydrospiro[2H-indolo-2,2-piperidine] derivatives were treated with perchloric acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 902–904, July, 1988.     

Spontaneous Bi-modification of polycrystalline Pt electrode: fabrication, characterization, and performance in formic acid electrooxidation

Spontaneous modification of polycrystalline Pt by irreversibly adsorbed bismuth was performed in BiCl₃ solution in concentrated hydrochloric acid under open-circuit conditions. After spontaneous modification, followed by extensive rinsing with water and drying, the surface was characterized using X-ray photoelectron spectroscopy and electrochemistry. Bi-oxy(chloride), oxide species, and metallic Bi were found at a submonolayer coverage on the Pt surface after spontaneous modification. The electrochemical response of Bi-modified polycrystalline Pt electrode in sulfuric acid solution exhibits a complex multi-peak feature, which is resulting in about constant redox charge (Bi species coverage) in the potential region from 0 to 0.9 V (vs. a standard hydrogen electrode). The spontaneously Bi-modified Pt catalyst in model studies exhibits a superior activity towards formic acid oxidation at fuel cell anode relevant potentials. The catalytic effect of bismuth oxy-species is explained in terms of both inhibition of CO_ad formation and oxidation of CO_ad in reaction with Bi-oxy-species.     

Carrier envelope phase stabilization of a Yb:KGW laser amplifier

In this paper we report on the active stabilization of the carrier envelope phase (CEP) of a Yb:KGW chirped pulse amplifier laser system seeded by a Yb-doped solid-state Kerr-lens mode-locked oscillator. The regenerative amplifier delivers 180 fs CEP stable pulses of 30 μJ-1 mJ energy at a repetition rate tunable from 1 to 200 kHz. The bandwidth of the feedback loop was extended by a factor of 5 using a specially designed high-pass filter, which resulted in a dramatic decrease of CEP jitter below 0.45 rad after the amplifier.     

Algebraic and abelian solutions to the projective translation equation

Let \({{\mathrm x}=(x,y)}\). A projective two-dimensional flow is a solution to a 2-dimensional projective translation equation (PrTE) \({(1-z)\phi({\mathrm x})=\phi(\phi({\mathrm x}z)(1-z)/z)}\), \({\phi:\mathbb{C}^{2}\mapsto\mathbb{C}^{2}}\). Previously we have found all solutions of the PrTE which are rational functions. The rational flow gives rise to a vector field \({\varpi(x,y)\bullet \varrho(x,y)}\) which is a pair of 2-homogenic rational functions. On the other hand, only very special pairs of 2-homogenic rational functions, such as vector fields, give rise to rational flows. The main ingredient in the proof of the classifying theorem is a reduction algorithm for a pair of 2-homogenic rational functions. This reduction method in fact allows us to derive more results. Namely, in this work we find all projective flows with rational vector fields whose orbits are algebraic curves. We call these flows abelian projective flows, since either these flows are described in terms of abelian functions and with the help of 1-homogenic birational plane transformations (1-BIR), and the orbits of these flows can be transformed into algebraic curves \({x^{A}(x-y)^{B}y^{C}\equiv{\mathrm{const.}}}\) (abelian flows of type I), or there exists a 1-BIR which transforms the orbits into the lines \({y\equiv{\mathrm{const.}}}\) (abelian flows of type II), and generally the latter flows are described in terms of non-arithmetic functions. Our second result classifies all abelian flows which are given by two variable algebraic functions. We call these flows algebraic projective flows, and these are abelian flows of type I. We also provide many examples of algebraic, abelian and non-abelian flows.     

Comparison of analytical and semi-preparative columns for high-performance liquid chromatography-solid-phase extraction-nuclear magnetic resonance

The application of analytical and semi-preparative columns in reversed-phase liquid chromatography-solid-phase extraction-nuclear magnetic resonance (HPLC-SPE-NMR) was compared. The work was aiming at separating a higher sample amount in a single run and in this way to reduce the necessary NMR measurement time of separated compounds. Several parameters for compound separation and trapping procedures were optimised: flow rate of HPLC and make-up water pumps, choice of stationary phase cartridges and drying time. The separation and loadability of nine model compounds on analytical and semi-preparative columns was determined, as well as the focussing capacity of SH-type SPE cartridges. It was found that a semi-preparative column--or multiple peak trapping on analytical columns--gave better results than a standard 4.6mm analytical column for non-polar compounds (e.g. flavonoid aglycones, sesquiterpene lactones, non-polar terpenes, logP>2), but for polar compounds (logP<-2) did not offer any advantage over an analytical column, or was even disadvantageous. For intermediately polar compounds (-2相似文献