Showing papers on "Derivative (chemistry) published in 2002"

Structure-activity relationships in 4-aminoquinoline antiplasmodials. The role of the group at the 7-position

Abstract: Antiplasmodial activities versus the chloroquine sensitive D10 strain of Plasmodium falciparum of a series of N1,N1-diethyl-N2-(4-quinolinyl)-1,2-ethanediamines with 11 different substituents at the 7-position on the quinoline ring have been investigated in vitro. Electron-withdrawing groups at the 7-position have been shown to lower the pKa of both the quinoline ring nitrogen atom and the tertiary amino nitrogen in the alkyl side chain. The quinoline nitrogen pKa ranges from 6.28 in the nitro derivative to 8.36 in the amino derivative, while the tertiary amino nitrogen has a pKa ranging between 7.65 in the trifluoromethyl derivative and 10.02 in the amino derivative. Calculation suggests that the resulting pH trapping of these compounds in the parasite food vacuole ranges between about 7% of that observed in chloroquine for the NO2 derivative and 97% in the amino derivative. A direct proportionality between antiplasmodial activity normalized for pH trapping and β-hematin inhibitory activity was observed....

3-phenoxy-4-pyridazinol derivative and herbicide composition containing the same

Abstract: A compound represented by the general formula (I) (wherein R1 is hydrogen, halogeno, alkyl, etc.; R2 is hydrogen, halogeno, alkyl, etc.; R3, R4, R5, R6, and R7 each independently is hydrogen, halogeno, optionally substituted alkyl, optionally substituted alkenyl, alkynyl, optionally substituted cycloalkyl, etc., provided that any adjacent two of R3, R4, R5, R6, and R7 may form an optionally substituted ring in cooperation with the carbon atoms bonded thereto; and m and n each independently is 0 or 1) or a salt or ester derivative of the compound; an agricultural chemical containing any of these as the active ingredient; and a herbicidal composition containing the compound and a second herbicidal compound as the active ingredients.

Thiazole compounds useful as inhibitors of protein kinase

Abstract: The present invention provides a compound of formula I: or a pharmaceutically acceptable derivative thereof. These compounds are inhibitors of protein kinases, particularly inhibitors of GSK3, Aurora2, and Syk mammalian protein kinases. The invention also provides pharmaceutically acceptable compositions comprising the compounds of the invention and methods of utilizing those compounds and compositions in the treatement of various protein kinase mediated disorders.

Diaryl sulfide derivative, addition salt thereof, and immunosuppressant

Abstract: A diaryl sulfide derivative having excellent immunosuppressive activity and reduced in side effects. The diaryl sulfide derivative is represented by the general formula 1: 1 {e.g., 2-amino-2-[4-3-benzyloxyphenylthio-2-chlorophenyl]propyl-1,3-propanediol}.

Diaryl ether derivative, addition salt thereof, and immunosuppressant

Abstract: A diaryl ether derivative having excellent immunosuppressive activity and reduced in side effects. The diaryl ether derivative is represented by the general formula (1): (1) {e.g., 2-amino-2-[4-(3-benzyloxyphenoxy)-2-chlorophenyl]propyl-1,3-propanediol}.

Formation of Transient Intermediates in Low-Temperature Photosensitized Oxidation of an 8-13C-Guanosine Derivative

Abstract: An 8-13C-labeled guanosine derivative, 2‘,3‘,5‘-O-tert-butyldimethylsilyl-N-tert-butyldimethylsilyl-8-13C-guanosine, was synthesized and its photosensitized oxidation with singlet oxygen carried out below −100 °C. Two transient intermediates that decompose directly to the final major product 5 and CO2 were detected by 13C NMR between −100 and −43 °C. The two intermediates are carbamic acids based on 13C NMR and 2D NMR (HMQC, HMBC) spectra and the formation of final product 5 and of 8-CO2. No endoperoxide intermediate could be detected by low-temperature NMR spectroscopy even at −100 °C. A reaction mechanism is proposed involving initial [4 + 2] cycloaddition of singlet oxygen to the imidazole ring to form an unstable endoperoxide, subsequent rearrangement of the endoperoxide to a dioxirane, and decomposition of the dioxirane to the two observed intermediates. Both oxygen atoms of CO2 are derived from a single oxygen molecule, which strongly supports a dioxirane structure for the precursor of the two obser...

Low-temperature photosensitized oxidation of a guanosine derivative and formation of an imidazole ring-opened product

Abstract: An organic-soluble guanosine derivative, 2‘,3‘,5‘-O-(tert-butyldimethylsilyl)guanosine (1), was prepared and its photosensitized oxidation was carried out in several solvents at various temperatures. Singlet oxygen is the reactive oxidizing agent responsible for this reaction. Neither an endoperoxide nor a dioxetane intermediate was detected by low-temperature NMR even at −78 °C. A product (A) with an oxidized imidazole ring was the only major product detected at room temperature; this compound could be isolated by low-temperature column chromatography and was characterized by 1H and 13C and mass spectroscopy. CO2 was the other major product. A small amount of the corresponding 8-oxo-7,8-dihydroguanosine derivative B was detected during the initial stage of the photooxidation and was shown to be intermediate in the formation of two products of extensive degradation, C and D. Reaction of 1 with the singlet oxygen analogues 4-methyl-1,2,4-triazoline-3,5-dione (MTAD) and 4-phenyl-1,2,4-triazoline-3,5-dione (...

Synthesis and two-electron redox behavior of diazuleno[2,1-a:1,2-c]naphthalenes.

Abstract: The Diels-Alder reaction of di-2-azulenylacetylene with tetraphenylcyclopentadienone afforded 7,8,9,10-tetraphenyldiazuleno[2,1-a:1,2-c]naphthalene in one pot via autoxidation of the presumed 1,2-di-2-azulenylbenzene derivative. In contrast, a similar reaction of bis(1-methoxycarbonyl-2-azulenyl)acetylene with tetraphenylcyclopentadienone gave the 1,2-di-2-azulenylbenzene derivative. The following cyclodehydrogenation reaction of the benzene derivative with iron(III) chloride afforded diazuleno[2,1-a:1,2-c]naphthalene 6,11-bismethoxycarbonyl derivative. The redox behavior of these novel diazuleno[2,1-a:1,2-c]naphthalenes was examined by cyclic voltammetry (CV). These compounds exhibited two-step oxidation waves at +0.22 to +0.71 V upon CV, which revealed the formation of a radical cation and dication stabilized by the fused two azulene rings under the electrochemical oxidation conditions. Since the 1,2-di-2-azulenylbenzene derivative was oxidized at higher oxidation potentials (+0.83 and +1.86 V), the fusion of the two azulene rings to naphthalene increased electron-donating properties because of the formation of a closed-shell dicationic structure. Formation of the radical cation was characterized by UV-vis spectroscopy under the electrochemical oxidation conditions, although no evidence was obtained for the presumed dication under the conditions of the UV-vis spectroscopy measurement.

Isoxazoline derivative and herbicide comprising the same as active ingredient

Abstract: An isoxazoline derivative which is represented by the general formula: [I] wherein R?1 and R2? represent an alkyl group and may be the same or different, R?3, R4, R5 and R6? represent a hydrogen atom, Y represents an aromatic heterocyclic group or aromatic condensed heterocyclic group which has a heteroatom selected from among a nitrogen atom, an oxygen atom and a sulfur atom, has five or six members, and may be substituted, and n represents an integer of 0 to 2. The isoxazoline derivative exhibits excellent herbicidal effect and selectivity between a crop and a weed.

Generalized Pattern Searches with Derivative Information

Abstract: Abstract.A common question asked by users of direct search algorithms is how to use derivative information at iterates where it is available. This paper addresses that question with respect to Generalized Pattern Search (GPS) methods for unconstrained and linearly constrained optimization. Specifically, this paper concentrates on the GPS pollstep. Polling is done to certify the need to refine the current mesh, and it requires O(n) function evaluations in the worst case. We show that the use of derivative information significantly reduces the maximum number of function evaluations necessary for pollsteps, even to a worst case of a single function evaluation with certain algorithmic choices given here. Furthermore, we show that rather rough approximations to the gradient are sufficient to reduce the pollstep to a single function evaluation. We prove that using these less expensive pollsteps does not weaken the known convergence properties of the method, all of which depend only on the pollstep.

Novel pyrrole derivatives as pharmaceutical agents

Abstract: Novel pyrrazole derivative compounds and their use as pharmaceutical agents, in particular their use as TGF-beta signal transduction inhibitors. The disclosed invention relates to compounds of the structure (I) wherein (I) is a four, five, or six membered saturated ring and X is C, O or S.

Supramolecular Aggregates Formed by Intermolecular Inclusion Complexation of Organo-Selenium Bridged Bis(cyclodextrin)s with Calix[4]arene Derivative

Abstract: A novel supramolecular assembly has been fabricated by the inclusion complexation between organo-selenium bridged bis(β-cyclodextrin)s 2 and calix[4]arene derivative 3 in water-acetonitrile (1:1) m...

Self-Curing System For Endodontic Sealant Applications

Abstract: A two-part self-curing endodontic sealing system comprises a thiourea derivative, such as acetyl thiourea, and a hydroperoxide, such as cumene hydroperoxide. The thiourea derivative is used as a reducing agent and the hydroperoxide is used as an oxidizing agent.

Oxo-transfer reaction from a bis(μ-oxo)dicopper(III) complex to sulfides

Abstract: Oxygenation of sulfides to the corresponding sulfoxides by a distinct bis(μ-oxo)dicopper(III) complex has been accomplished for the first time using 2-(2-pyridyl)ethylamine derivative LPy1Bz (N-ethyl-N-[2-(2-pyridyl)ethyl]-α,α-dideuteriobenzylamine) as the supporting ligand. Detailed kinetic analysis has indicated that the reaction consists of two distinct steps, where the first quick process is association of the substrate to the bis(μ-oxo)dicopper(III) complex (k1) and the second slow process is intramolecular oxygen atom transfer from the copper−oxo species to the substrate in the associated complex (k2). The rate constant k2 of the second process is rather insensitive to the oxidation potential of the substrates, suggesting that the oxo-transfer reaction proceeds via a mechanism involving direct oxygen atom transfer rather than a mechanism involving electron transfer.

Proton conductor, production method thereof, and electrochemical device using the same

Abstract: A proton conductor mainly contains a carbonaceous material derivative, such as, a fullerene derivative, a carbon cluster derivative, or a tubular carbonaceous material derivative in which groups capable of transferring protons, for example, —OH groups or —OSO 3 H groups are introduced to carbon atoms of the carbonaceous material derivative. The proton conductor is produced typically by compacting a powder of the carbonaceous material derivative. The proton conductor is usable, even in a dry state, in a wide temperature range including ordinary temperature. In particular, the proton conductor mainly containing the carbon cluster derivative is advantageous in increasing the strength and extending the selection range of raw materials. An electrochemical device, such as, a fuel cell, that employs the proton conductor is not limited by atmospheric conditions and can be of a small and simple construction. The proton conductor may contain a polymer in addition to the carbonaceous material derivative, which conductor can be formed, typically by extrusion molding, into a thin film having a large strength, a high gas permeation preventive ability, and a good proton conductivity.

Novel 6-substituted uracil derivative and therapeutic agent for allergic disease

Abstract: PROBLEM TO BE SOLVED: To provide a new compound having not only antihistamine effects but also antiinflammatory effects. SOLUTION: A urasil derivative represented by general formula (I) or a pharmacologically acceptable salt thereof is used for medicinal applications. In formula (I), R 1 is a hydrogen atom, a substituted or unsubstituted 1-4C alkyl group, or a substituted or unsubstituted 7-10C aralkyl group; R 2 is a hydrogen atom or a 1-4C alkyl group; Ar 1 is a substituted or unsubstituted aromatic group, or a substituted or unsubstituted aromatic heterocyclic group; Ar 2 and Ar 3 are each a substituted or unsubstituted phenyl group, or a substituted or unsubstituted monocyclic aromatic heterocyclic group, and may form a third ring by a group linking to both Ar 2 and Ar 3 ; X is a methine (CH) group or a nitrogen atom; Y is a single bond or an oxygen atom when X is a methine group, and is a single bond when X is a nitrogen atom; Z is a hydrogen atom or a hydroxy group when X is a methine group and Y is a single bond, and is a hydrogen atom when X is a methine group and Y is an oxygen atom or when X is a nitrogen atom (and Y is a single bond); and m is 2-6. COPYRIGHT: (C)2006,JPO&NCIPI

Preparation and Stille cross-coupling reaction of the first organotin reagents of azulenes. Easy access to poly(azulen-6-yl)benzene derivatives

Abstract: The first versatile organometallic reagents derived from azulenes, ie, 6-(tri-n-butylstannyl)azulene (1a) and its 1,3-diethoxycarbonyl derivative (1b), have been prepared by Pd(0)-catalyzed direct stannylation of 6-bromoazulenes with bis(tri-n-butyltin) We demonstrate the utility of the reagents in the Stille cross-coupling reaction with aryl, acyl and azulenyl halides to afford 6-aryl-, 6-acyl- and bi-azulenes in good yield Furthermore, the methodology was applied to the synthesis of poly(azulen-6-yl)benzene derivatives The reaction of 1b with 1,4-di-, 1,3,5-tri-, 1,2,4,5-tetra- and hexabromobenzenes afforded 1,4-di-, 1,3,5-tri-, 1,2,4,5-tetra-, 1,2,4-tri- and 1,2,3,5-tetra(azulen-6-yl)benzene derivatives (18, 20, 22, 24 and 25) The redox behavior of 18 and 22 was examined by cyclic voltammetry (CV) and compared with those of 20 and 24 reported previously In contrast to the three-step reduction of 20, the compound 18 exhibited a reversible one-step two-electron reduction wave at −130 V upon CV, which revealed the formation of a closed-shell dianion The four azulen-6-yl substituents on benzene in a 1,2,4,5 relationship increased electron-accepting properties because of the formation of a closed-shell dianion stabilized by four azulen-6-yl groups As expected, the compound 22 exhibited a color change during the electrochemical reduction However, the reverse oxidation did not regenerate the spectrum of 22 due to the low stability of the presumed dianionic species under the conditions of the UV–vis measurement

The thermal reaction of sterically hindered nitroxyl radicals with allylic and benzylic substrates: experimental and computational evidence for divergent mechanisms.

Abstract: The reaction of stable sterically hindered nitroxyl radicals with benzylic and allylic substrates was investigated. An allyloxyamine derivative was obtained by the reaction of 2 molar equiv of a nitroxyl radical with an unactivated alkene. Experimental and computational evidence is consistent with a low-energy pathway involving addition of the nitroxyl radical to the double bond followed by H-atom abstraction from the intermediate by another equivalent of nitroxyl radical.

2-acylaminothiazole derivative or its salt

Abstract: A 2-acylaminothiazole derivative having an activity of increasing platelets based on an excellent effect of accelerating magakaryocyte colony formation or a pharmaceutically acceptable salt thereof. Namely, a compound efficacious in treating thrombopenia or its salt.