Showing papers on "Pyrazole published in 1996"

Palladium-Catalyzed Asymmetric Allylic Amination Using Ferrocenyl Pyrazole Ligands: Steric Control of η3-Allyl Configuration and Site-Selective Nucleophilic Attack

Abstract: The reaction of 1,3-diphenylallylethyl carbonate (1) with benzylamine to afford the secondary amine 2 is effectively catalyzed by Pd-complexes containing chiral ferrocenyl pyrazole ligands. The highest enantioselectivity (99% ee) was obtained using ligand 3a, 1-{(S)-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethyl}-3-(1-adamantyl)-1H-pyrazole. Four different cationic Pd-allyl intermediates, 4a, 4c, 4j, and 4k (containing ligands 3a, 3c, 3j, and 3k, respectively), formed during the catalytic reaction were studied in solution by 2D-NMR spectroscopy, with the aim of clarifying configurational aspects. Depending on the size and shape of the substituent in position 3 of the pyrazole ring, it was found that the major diastereoisomeric form of these complexes either adopts an exo-syn-syn (ligands 3a and 3c, 1-{(S)-1-[(R)-2-(diphenylphosphino)ferrocenyl]-ethyl}-3-phenyl-5-methyl-1H-pyrazole) or an exo-syn-anti configuration (ligands 3j, 1-{(S)-1-[(R)-2-(diphenylphosphino)ferrocenyl]ethyl}-3-(9-anthryl)-5-methyl-1H-py...

Pyrazole derivatives and processes for the preparation thereof

Abstract: 4-Amino-1H-pyrazolo[3,4-d]pyrimidine derivatives of formula (I) wherein the symbols are as defined in claim (1), and intermediates for their manufacture are described. The compounds of formula (I) inhibit especially the tyrosine kinase activity of the receptor for epidermal growth factor and can be used, for example, in the case of epidermal hyperproliferation (psoriasis) and as anti-tumour agents.

Novel Ferrocene‐Based Mono‐ and Bifunctional Tri‐1‐pyrazolylborate Ligands

Abstract: The reaction of (dibromoboryl)ferrocene (1a) with pyrazole/NEt3 gave the ferrocenyltri-1-pyrazolylborate ligand 2. Its thallium(I) derivative 2-Tl provides the first example of a polymeric structure with bridging tri-1-pyrazolylborate units in the solid state. The trinuclear iron complex 2-Fe, which is related to 1,1′-terferrocene, was obtained by reaction of 2 with FeCl2. The bis(polydentate) ligand 1,1′-ferrocenediyl-bis(tri-1-pyrazolylborate) (3-Li) was prepared from 1,1′-bis-[bis(dimethylamino)boryl]ferrocene (1c) and a mixture of lithium pyrazolide/pyrazole in refluxing toluene/THF. 3-Li reacts with TlNO3 to give the thallium(I) complex 3-Tl.

Compounds for and method of inhibiting phosphodiesterase iv

Abstract: Novel compounds which are effective PDE IV inhibitors are disclosed. The compounds possess similar or improved PDE IV inhibition as compared to rolipram, with improved selectivity with regard to, e.g., PDE III inhibition. Preferred compounds are 3-(3-cyclopentyloxy-4-methoxy-benzylamino)-4-hydroxymethyl pyrazole and 3-(3-cyclopentyloxy-4-methoxybenzylamino)-4-methoxymethylpyrazole.

1,2,4-TRIAZOLO[1,5-c]PYRIMIDINE HETEROCYCLIC ANALOGUES HAVING ANTAGONISTIC ACTIVITY ON ADENOSINE A2a RECEPTOR

Abstract: The compounds of general formula (I), wherein A is a pyrazole, imidazole or triazole ring, R is formula (II), wherein R1 and R2, which are the same or different, are H, OH, halogen, C1-4 alkoxy, C1-4 alkyl, nitro, amino, cyano, C1-4 haloalkyl, C1-4 haloalkoxy, carboxy, carboxamido groups; moreover the OH group, together with one of R1 or R2, or R1 and R2, can form the methylenedioxy group -O-CH2-O-; n is an integer from 0 to 4, are useful as therapeutical agents.

Pesticidal sulfur compounds

Abstract: Pyrazole, pyrrole and imidazole derivatives having formula (I) or (II) wherein =X is =NR3, =O or an electron pair and Q comprises certain pyrazole, pyrrole and imidazole structures which, together with the remaining substituents, are defined in the description, are useful for controlling arthropod, nematodes, helminth or protozoan pests.

Herbicidally active pyrazol-4-ylbenzoyl compounds

Abstract: Pyrazol-4-ylbenzoyl compounds of the formula I ##STR1## where Z is a 5- or 6-membered heterocyclic saturated or unsaturated radical, Q is a pyrazole ring and L and M are as defined in the specification, their use as herbicidal compounds and to processes for preparing the compounds.

Synthesis of methyl 4-aryl-6-methyl-4,7-dihydro-1H-pyrazolo-[3,4-b]pyridine-5-carboxylates from methyl 4-aryl-6-methyl-2-oxo-1,2,3,4-tetrahydropyridine-5-carboxylates

Abstract: Novel methyl 4,7-dihydro-1H-pyrazolo[3,4-b]pyridine-5-carboxylates 3a–e have been prepared in a two step procedure from the readily available 2-oxo-1,2,3,4-tetrahydropyridine-5-carboxylates 1a–e by treatment with the Vilsmeier–Haack reagent. Further treatment of the novel o-chloroformyl substituted methyl 1,4-dihydropyridine-5-carboxylates 2a–e with hydrazine affords the corresponding methyl pyrazolo[3,4-b]pyridine-5-carboxylates in good yields. Semiempirical calculations reveal a favoured geometry with a boat conformation in the dihydropyridine system and a planar pyrazole ring.

Pyrazole-related nucleosides. 4. Synthesis and antitumor activity of some 1-tetrahydropyranyl-4-substituted pyrazoles.

Abstract: Continuing our studies on the structure-activity relationships of some pyrazole nucleosides (1a-h) structurally related to ribavirin, tiazofurin and selenazofurin, we describe here the synthesis and antitumor/antiviral/antimicrobial activity of a new series of 1-tetrahydropyranyl-4-substituted pyrazoles. In this study, the tetrahydropyranyl moiety (THP), designed as a mimic of the glycosidic portion of the parent compounds 1a-h, has led to a few derivatives with moderate cytotoxic activity against leukemia/lymphoma and solid tumor-derived cell lines (IC50 14-100 microM). The compounds obtained through substitution of the ribofuranosyl moiety by the THP moiety were still active, the free heterocyclic bases were devoid of any activity.

A pyrazolate-bridged cyclic tetranuclear copper(II) complex: synthesis, crystal structure and magnetic properties

Abstract: A new pyrazolate-bridged tetranuclear copper(II) complex [{CuL(H2O)}4]·12H2O (H2L = 5-methoxycarbonylpyrazole-3-carboxylic acid) was synthesized and its crystal structure determined. The molecule has C2 symmetry and consists of four copper atoms bridged by four planar L ligands through the nitrogen atoms of the pyrazole groups to form a (–Cu–N–N–)4 12-membered ring. The co-ordination of each copper is distorted square planar. The basal plane of each copper atom is nearly parallel to a neighbouring pyrazole plane and perpendicular to another neighbouring pyrazole plane. In the crystal there is a hydrogen-bond network between water molecules and carboxylate groups which may control the packing. The magnetic properties of the complex have also been investigated down to 5 K. The fitting of the experimental data using a Heisenberg Hamiltonian shows that the exchange interaction between the copper atoms propagated through the monopyrazolate bridge is antiferromagnetic with J=–12.34 cm–1. The reason for this small value relative to those in di-µ-pyrazolato-dicopper(II) complexes is discussed.

Cyclopropylpyrroloindole-oligopeptide anticancer agents

Abstract: The invention is directed to novel cyclopropylpyrroloindole-oligopeptide compounds which are useful as anticancer agents. The novel cyclopropylpyrroloindole-oligopeptide compounds have general structure (I), wherein Het1 and Het2 are individually selected from the group consisting of pyrrole, imidazole, triazole, thiophene, furan, thiazole, oxazole and pyrazole, R is selected from the group consisting of a valence bond; a C?1?-C6 alkyl; a C2-C6 alkenyl; a C2-C6 alkynyl; and an ortho, meta or para linked aromatic group, A is selected from the group consisting of a C1-C6 alkyl group; and amidine or derivative thereof; a guanidine; a secondary, tertiary or quaternary ammonium salt; and a sulfonium salt, n is 0 to 3, and m is 0 to 3.

Thiazolidinedione derivatives or salts thereof and pharmaceutical compositions containing the same

Abstract: This invention relates to a thiazolidinedione derivative represented by the following formula (1): (1) wherein R1 and R2 individually represent H, a halogen atom, or a halogen-substituted or -unsubstituted lower alkyl or alkoxy group, and R1 and R2 may be coupled together to form a ring of an alkylenedioxy chain, Xrepresents a nitrogen atom or a CH group, A represents a substituted or unsubstituted imidazolidinone, pyrrolidinone, imidazole or pyrazole ring, or a salt thereof; and a pharmaceutical composition containing the thiazolidinedione derivative or a salt thereof. The above compound has excellent blood sugar-lowering action and blood lipid-lowering action and is useful as a therapeutic agent for diabetes.

Synthesis and QSAR of Herbicidal 3-Pyrazolyl α,α,α-Trifluorotolyl Ethers

Abstract: Pyrazole nitrophenyl ethers (PPEs) were recently identified as a novel class of chemistry exerting herbicidal effects by inhibition of protoporphyrinogen IX oxidase. This area of chemistry has been extended to include herbicidal pyrazolyl fluorotolyl ethers. In these compounds, a trifluoromethyl group substitutes for the 4'-nitro group found in the original herbicides and in classical nitrodiphenyl ether hebicides. Fluoroanisole pyrazole ethers, in which a trifluoromethoxy group replaces the nitro group of diphenyl ether herbicides, are also described. The shift from 4'-nitro to 4'-trifluoromethyl substitution, which is conservative in terms of electrostatics, produced a novel class of herbicide with substantial pre-emergent activity on narrowleaf weed species. Quantitative structure/activity relationships obtained with respect to substitution on the pyrazole ring and at the 3'-position of the fluorotolyl moiety can be summarized effectively by comparative molecular field analysis. In general, 5-methanesulfonyl fluorotoluidide ethers were found to be most active.

Novel 5-amino-3-cyano-4-ethylsulfinyl-1-phenyl-pyrazole compounds and their use as pesticides

Abstract: The invention relates to 1-arylpyrazoles of general formula (I), wherein X is chlorine or bromine; Y is trifluoromethyl or trifluoromethoxy and R1 is hydrogen, methyl or ethyl, and to their use as pesticides.

Inhibition of the acid corrosion of iron with new pyrazole derivatives

Abstract: Some new synthetized pyrazole organic-type compounds have been tested as inhibitors for the corrosion of iron in 1M HCl by weight-loss and electrochemical polarization methods. Both techniques gave the same order of inhibition. The compound l,3-bis(3' chloromethyl-5'-methyl-1'-pyrazolyl)propane (Inh.9) was the better inhibitor and its inhibition efficiency increased with increase of concentration and reaching 95% at 4.10-4 M. Polarization measurements have shown that the pyrazole substances studied inhibited both the anodic reaction of iron dissolution and the cathodic reaction of hydrogen evolution. These products act without changing the mechanism of the cathodic hydrogen evolution reaction. The corrosion inhibition of pyrazoles studied is regarded by a simple blocked fraction of the electrode surface related to adsorption of inhibitor species according to Langmuir isotherm model on the iron surface. The introduction in the pyrazole ring of a substituent such as -OH, -CO2 H, -CO2 CH3 , and -Cl in the position 3, enhances the inhibiting effect of the pyrazole compounds. The effect of temperature on the corrosion behaviour of iron indicated that inhibition efficiencies of (Inh.9) increased with increasing temperature in the range of 25 - 50 °C. The apparent activation energy for iron corrosion process are modified by addition of (Inh.9).

Pyrazole derivatives and herbicides

Abstract: Pyrazole derivatives represented by general formula (1a) or (1b) (wherein R1 represents hydrogen or a protecting group acceptable in a pesticide; R?2 and R3? represent each phenyl, 1-naphthyl, 2-naphthyl, a 5- or 6-membered heterocycle, etc.; and R4 represents hydrogen, halogeno, alkyl, alkoxy or alkylthio) and herbicides containing the same.

Pyrazole compounds and pharmaceutical compositions

Abstract: A pyrazole compound of formula (I), wherein R?1 and R3? are the same or different and each is independently hydrogen, lower alkyl, ar(lower)alkyl, heterocyclic group, or aryl which may have one or more suitable substituent(s), R2 is hydrogen, lower alkyl, or ar(lower)alkyl which may have one or more suitable substituent(s), and R4 is hydrogen or lower alkyl, or a salt thereof. The pyrazole compound (I) and a salt thereof of the present invention are adenosine antagonists and are useful for the prevention and/or the treatment of ischemic heart diseases (e.g. angina, etc.), peripheral vascular diseases (e.g. claudication, etc.), cerebral ischemia, migraine, diabetes, depression, Parkinson's disease, and the like.