Showing papers on "Pyrazole published in 1993"

Process for producing 4,5-diamino pyrazole derivatives, their use for colouring hair and novel pyrazole derivatives

Abstract: The present invention relates to a process for producing 4,5-diamino pyrazole derivatives of general formula (I) in which R1 and R2 are mutually independently hydrogen, a C1 to C6 alkyl residue or a C2 to C4 hydroxy alkyl residue, which may be used as colorant pre-products, e.g. for hair colorants, and novel pyrzole derivatives. The use of the process of the invention makes it possible to obtain 4,5-diamino pyrazole derivatives of general formula (I) without isomers and with good yields.

Novel pyrazole derivatives, method of preparing them and pharmaceutical compositions in which they are present

Abstract: The present invention relates to compounds of the formula: ##STR1## These compounds are useful in pharmaceuticals in which cannabis is known to be involved.

Composition for the oxidative dyeing of hair containing 4,5-diaminopyrazole derivatives as well as new 4,5-diaminopyrazole derivatives and process for their synthesis

Abstract: The composition for oxidative dyeing of hair based on a combination of developer substances and coupler substances, contains as a developer substance 4,5-diamino-1-(4'-methoxybenzyl)pyrazole, 4,5-diamino-1-(4'-methylbenzyl)pyrazole, 4,5-diamino-1-(4'-chlorobenzyl)pyrazole, 4,5-diamino-1-(3'-methoxybenzyl)pyrazole, 4-amino-1-(4'-methoxy-benzyl) -5-methylaminopyrazole or 4-amino-5-(2'-hydroxyethyl)amino-1-(4'-methoxybenzyl)pyrazole.

Nonpeptide angiotensin II antagonists derived from 1H-pyrazole-5-carboxylates and 4-aryl-1H-imidazole-5-carboxylates

Abstract: Two series of potential angiotensin II antagonists derived from carboxyl-functionalized "diazole" heterocycles have been prepared and evaluated. Initially, a limited investigation of 4-arylimidazole-5-carboxylates led to 2-n-butyl-4-(2-chlorophenyl)-1-[[2'-(1H-tetrazol-5-yl)biphenyl-4-y l] methyl]-1H-imidazole-5-carboxylic acid (12b), which was found to be a highly potent antagonist of the rabbit aorta AT1 receptor (IC50 0.55 nM). In conscious, normotensive rats, 12b at 0.1 mg/kg iv inhibited the pressor response to AII by 88%, with a duration of > 6 h. More extensively studied was an isosteric series of 3-alkyl-4-[[2'-(1H-tetrazol-5-yl)biphenyl-4-yl]methyl]-1H-pyrazole -5- carboxylates bearing aryl, alkyl, or aralkyl substituents at N1. These compounds were available in highly regioselective fashion via condensation of a substituted hydrazine hydrochloride with a 2-(methoxyimino)-4-oxoalkanoate intermediate. In vitro, the most potent pyrazolecarboxylic acids had n-butyl at C3 and were substituted at N1 by such groups as 2,6-dichlorophenyl (19h), 2-(trifluoromethyl)phenyl (19k), benzyl (19t), and phenethyl (19u), all with IC50 values of 0.18-0.24 nM. Although less potent in the receptor assay, 3-n-propylpyrazolecarboxylic acids were at least as effective as their butyl counterparts in vivo. Several of the pyrazolecarboxylic acid derivatives demonstrated potent, long-lasting oral activity in rats. At 1 mg/kg po, the 1-benzyl-3-butyl (19t), 1-(2,6-dichlorophenyl)-3-propyl (19v), 3-propyl-1-(2,2,2-trifluoroethyl) (19y), and 1-benzyl-3-propyl (19z) analogues all gave > or = 75% inhibition of the AII pressor response in the rat model, with duration of action > 23 h.

Nonprostanoid prostacyclin mimetics. 5. Structure-activity relationships associated with [3-[4-(4,5-diphenyl-2-oxazolyl)-5- oxazolyl]phenoxy]acetic acid.

Abstract: cis-[3-[2-(4,5-Diphenyl-2-oxazolyl)ethenyl]phenoxy]acetic acid (3) was previously identified as a nonprostanoid prostacyclin (PGI2) mimetic that potently inhibits ADP-induced aggregation of human platelets with an IC50 of 0.18 microM. As part of an effort to further explore structure-activity relationships for this class of platelet inhibitor and to provide additional insight into the nonprostanoid PGI2 mimetic pharmacophore, the effect of constraining the cis-olefin moiety of 3 into various ring systems was examined. Incorporation of the cis-olefin of 3 into either an oxazole (26) or an unsubstituted pyrazole (35) heterocycle provided compounds that are equipotent with progenitor 3. However, the oxazole 11f, which is isomeric with 26, inhibits ADP-induced human platelet aggregation in vitro with an IC50 of 0.027 microM, 6-fold more potent than 3, 26, or 35. These results suggest that the central oxazole ring of 11f is functioning as more than a simple scaffold that provides optimal stereodefinition for interaction with the PGI2 receptor. The nitrogen atom of the central heterocycle of 11f is postulated to engage in hydrogen-bond formation with a donor moiety in the PGI2 receptor protein, an interaction not available to 26 due to the markedly different topology. In support of this contention, the crystal structures of 11f and 26 contain strong intermolecular hydrogen bonds between the carboxylic acid hydrogen atom and the nitrogen atom of the central oxazole ring. Although 11f and 26 are exact isosteres and could, in principle, adopt the same molecular packing arrangement in the solid state, this is not the case, and the intermolecular hydrogen-bonding interactions in 11f and 26 are accommodated by entirely different molecular packing arrangements. Incorporation of the olefin moiety of 3 into a benzene ring provided a compound, 40, over 60-fold weaker with an IC50 of 11.1 microM. The affinities of 11f, 26, 31, 32, and 40 for the human platelet PGI2 receptor, determined by displacement of [3H]iloprost, correlated with inhibition of platelet function. The solid-state structures of 11f, 26, 31, 32, and 40 were determined and revealed that the more potent compounds 11f and 26 adopt a relatively planar overall topography. In contrast, the central phenyl ring and the phenoxy ring of the weakly active compound 40 are rotated by 53 degrees from planarity. The chemical shifts of the protons of the phenoxy rings of 3, 11f, 18, 26, 31, 32, and 40 suggest that in solution 3, 11f, 18, and 26 adopt a planar conformation while 40 does not.(ABSTRACT TRUNCATED AT 400 WORDS)

. 3,5-diphenyl-1H-pyrazole derivatives. XI. N-aryl-5(3)-phenyl-4-(3,5- diphenyl-1-pyrazolyl)-3(5)-pyrazole amines, 5-substituted 4,5-dihydro-3-phenyl-4-(3,5-diphenyl-1-pyrazolyl)-1H-pyrazoles and 2,6-disubstituted 1,6-dihydro-4- phenyl-5-(3,5-diphenyl-1-pyrazolyl)pyrimidines with antipyretic, antiinflammatory and other activities.

Abstract: The synthesis of N-aryl-5(3)-phenyl-4-(3,5-diphenyl-1-pyrazolyl)-3(5)- pyrazoleamines 3 by reaction of some N-aryl-3-oxo-3-phenyl-2-(3,5-diphenyl-1- pyrazolyl)propanecarbothioamides with hydrazine is described. Also prepared were 4,5-dihydro-3-phenyl-4-(3,5-diphenyl-1-pyrazolyl)-1H-pyrazoles 6 and 1,6-dihydro-4-phenyl-5-(3,5-diphenyl-1-pyrazolyl)pyrimidines 7 by reaction of 1-phenyl-2-(3,5-diphenyl-1-pyrazolyl)-2-buten-1-one with hydrazine or guanidine and benzamidine, respectively. Some compounds 3, 6 and 7 showed remarkable antipyretic, antiinflammatory and in vitro platelet antiaggregating activities, as well as weak analgesic, antiarrhythmic, hypotensive and local anesthetic activities in rats and mice.

Experimental (13C and 15N NMR spectroscopy) and theoretical (6–31G) study of the protonation of N‐methylazoles and N‐methylbenzazoles

Abstract: The 13 C and 11 N NMR spectra of 11 N-methyl derivatives of azoles and benzazoles (imidazole, pyrazole, 1,2,4 triazole, indole, benzimidazole, 2H-inidazole, 1H-indazole, 2H-benzotriazole, 1H-benzotriazole and carbazole) in trifluoroacetic and sulfuric acid are reported. Quaternary salts were used asmodel compound. In the care of azoles (from pyrrole to pentazole) ab initio calculations at the 6-31G level were carried out to determine the protonation site

Coordination properties of the didentate N,O ligand 1-(2-hydroxyethyl)-3,5-dimethylpyrazole (hl). Crystal structure of [Cu(HL)2(NO3)2] and [Cu(L)Br]2

Abstract: The didentate N,O donor ligand 1-(2-hydroxyethyl)-3,5-dimethylpyrazole (N-hed) renders two kinds of coordination compounds, viz. [M(N-hed)2(NO3)2] with M=Co, Ni, Cu, and Zn, [Ni(N-hed)2(NCS)2], and [Cu(N-hed)2Cl2] in which the ligand is neutral, and [Cu(N-oed)X]2 with X=Cl, Br, and NO3 in which the ligand N-hed is in its deprotonated form, viz. 1-(2-oxidoethyl)-3,5-dimethylpyrazole (N-oed). The crystal structure of [Cu(N-hed)2(NO3)2] shows it to be mononuclear, with the copper ion at a centre of symmetry. Monoclinic, space group P21/c, a = 7.8176(8), b = 14.93(2), c = 8.4076(8) A, β = 92.62(2)°, Z = 2; R = 0.036 (Rw = 0.038) for 2132 significant reflections. The copper(II) ion is in a tetragonal-distorted, elongated-octahedral environment of two trans pyrazole nitrogen atoms at 1.974(2) A, two trans hydroxyl oxygen atoms at 1.991(2) A, and two trans oxygen atoms of monodentate coordinated nitrate anions at 2.561(2) A. The structure is stabilized by strong intramolecular hydrogen bonds between the hydroxyl group of the coordinated ligand and an oxygen atom of the coordinated nitrate ion with a short O-O distance of 2.599(2) A. The metal ions in the compounds [M(N-hed)2X2] are octahedrally surrounded by two nitrogen and two oxygen atoms of the ligand and by two anion donor atoms (respectively O, N, or Cl). The crystal structure of [Cu(N-oed)Br]2 shows it to be dinuclear. Triclinic, space group P2/1, a = 4.5213(6), b = 8.484(1), c = 13.052(7) A, α = 81.50(3), β = 85.79(4), γ = 77.79(2)°, Z = 1, R = 0.148 (Rw = 0.224) for 1534 reflections. The copper ions are bridged by two oxo atoms of the deprotonated ligands with a Cu-Cu distance of 3.042(4) A. Each Cu(II) ion is in a distorted square-planar O2NBr environment. The compounds [Cu(N-oed)X]2 are diamagnetic and EPR-silent.

Synthesis and Mesomorphic Properties of 3,5-bis-(p-n-Alkoxyphenyl)lsoxazole and 3,5-bis-(p-n-Alkoxyphenyl)Pyrazole

Abstract: The synthesis and mesomorphic behavior of 3,5-bis-(p-n-alkoxyphenyl)isoxazole (series I) and 3,5-bis-(p-n-alkoxyphenyl)pyrazole (series II) are reported for the number of carbon atoms (n) in the alkoxy chains varying from three to eight. Series I shows an enantiotropic nematic phase for all n and an enantiotropic smectic phase for n ⩾ 6. Series II shows one smectic phase SI for all n and an additional smectic phase SII for n ⩾ 6. From optical and X-ray data, the smectic phase of series I is identified as smectic C and in series II the SI phase is classified as smectic A and SII as a smectic C with a temperature dependent tilt angle. The 1-methyl substituted pyrazole was prepared and did not show mesophases.

New substituted pyrazole derivatives, processes for their preparation and their use as herbicides

Abstract: New substituted pyrazole derivatives of general formula (I) (see formula (I)) are described in which R1, R2, R3, R4, R5 and R6 have the meanings given in the description, processes for their preparation, as well as intermediates, and their use as herbicides.

Heterocyclic azole nonlinear optical chromophores. 1. Donor-acceptor substituted pyrazole derivatives

Abstract: We have described the synthesis of a variety of 1,3,1,4, and 1,5 donor-acceptor conjugation extended substituted pyrazole derivatives and have studied their spectr6scopic and nonlinear optical properties. These materials are thermally stable and absorb strongly in the UV-visible region, albeit at much shorter wavelengths than comparably substituted cyclic azapolyenes such as 2-pyrazolines. Quadratic hyperpolarizability measurements suggest that the pyrazoles are significantly nonlinear, and that 1,3 and 1,4 substitution is preferred. 1,5 substitution causes a significant drop in the nonlinearity and a blue shift in the long-wavelength absorption maximum, presumably due to a twisting and partial deconjugation of the substituents to relieve unfavorable steric interactions. The experimental results are compared with those predicted by simple “finite field” computational procedures.

Synthesis and reactions of N-substituted pyrazolo-3-sulfolenes

Abstract: N-Toluenesulfonyl- and N-(anilinocarbonyl)pyrazolo-3-sulfolenes have been prepared from the protected oxotetrahydrothiophenecarbaldehyde (7) via a sequence of hydrazone formation, ketal hydrolysis, cyclization, dehydration, and oxidation reactions. These N-substituents migrate between the two nitrogen atoms of the pyrazole ring at different stages. Extrusion of SO 2 from N-anilinocarbonylpyrazolo-3-sulfolenes was achieved at 180-200°C and the transient intermediate, the pyrazolo-o-quniodimethane, could be trapped with dienophiles

Pyrazole-containing pigment derivatives

Abstract: Pyrazole derivatives of a variety of polycyclic pigments, particularly quinacridone pigments, corresponding to the general formula ##STR1## wherein Q is the primary pigment structure; and the use of such derivatives as additives to pigment systems to provide a broad range of performance benefits to the resulting pigment compositions.

Synthesewege zu (μ1-HO)Zn21-Komplexen

Abstract: Synthetic Pathways for (μ1-HO)Zn2 Complexes The reactions of the 3-substituted kalium hydrotris(pyrazolyl)1-borates 1c, d (Rtert1-butyl, anisyl) with Zn(ClO4)2 · 6 H2O produce the dinuclear μ1-hydroxo complexes [L3Zn – O(H) – ZnL3](ClO4)3 (2a, b; L5-tert1-butylpyrazole, 5-anisylpyrazole), due to hydrolytic cleavage of the B – N bonds. These and similar complexes (2c, d;5-tert1-butyl-3-methylpyrazole, 5-phenylpyrazole) are also accessible directly from Zn(ClO4)2 · 6 H2O, the substituted pyrazole, and KOH, and in one case (2b; L5-anisylpyrazole) by hydrolytic cleavage of [HB(3-anisylpyrazolyl)3ZnEt] with perchloric acid. With other pyrazole and imidazole ligands, the Zn(ClO4)2/L/KOH reaction produces the simple complexes [ZnL6](ClO4)2 (3a, b; Lpyrazole, 3-methyl-5-phenylpyrazole) and [ZnL4](ClO4)2 (4; L2-methylimidazole). The crystal structures of 2a and 4, each containing tetrahedrally coordinated zinc atoms, have been determined.

Synthesis, crystal structure and magnetic properties of a dinuclear copper(II) complex with 1,1′-(4-methylpyrazole-3,5-diyl)diacetaldehyde dioxime. Evidence for both classical and zwitterion structures

Abstract: The reaction of 1,1′-(4-methylpyrazole-3,5-diyl)diacetaldehyde dioxime (H3L) with CuCl2·2H2O produces two different isomeric dinuclear co-ordination compounds according to the temperature. Analytical results indicated the same composition [Cu2(H2L)2Cl2]·2H2O. One isomer (1) crystallized at 15 °C in the monoclinic space group P21/a with a= 11.490(5), b= 16.287(14), c= 6.253(4)A, β= 97.78(4)° and Z= 2. Refinement of 1983 reflections with I > 3σ(I) gave a final R= 0.025 (R′= 0.027). The second isomer (2) crystallized at 25 °C in the triclinic system, space group P and a= 8.520(15), b= 8.607(18), c= 8.671(14), α= 75.27(15), β= 69.96(17), γ= 76.66(15)° and Z= 1; R= 0.027 (R′= 0.031) for 2964 significant reflections. The molecular structures of the two isomers are closely related; the centrosymmetric dinuclear [Cu2(H2L)2Cl2] unit is almost planar. Each copper atom is five-co-ordinated in a distorted square-based pyramid involving an N3O in-plane donor set, with the oxygen atom of the zwitterionic form of the oxime group, the nitrogen atom of the classical form of the oxime group and two nitrogen atoms of the pyrazole heterocycle; the axial ligand is a chloride ion. The two water molecules are linked by hydrogen bonds to the oxime function. In 1 the bonding is O–H ⋯ OH2(classical structure), in 2 it is N–H ⋯ OH2(zwitterionic structure). In the IR spectrum the ν(N–H) vibration is observed only for compound 1. Magnetic susceptibility measurements performed from 5 to 300 K provides evidence of the existence of strong antiferromagnetic exchange interactions between the copper(II) ions (J=–159 cm–1 for isomer 2). These results are discussed on the basis of the structural features.