Showing papers on "Pyrazole published in 1984"
73 citations
TL;DR: In this paper, 13C shielding data for 100 derivatives of pyrazole are reported, including methyl, ethyl, n-propyl, tert-butyl, phenyl, hydroxymethyl, carboxyl, ethoxycarbonyl, cyano, amino, hydrazino, nitro, azido, chloro, bromo and iodo groups.
Abstract: 13C shielding data for 100 derivatives of pyrazole are reported. These include methyl, ethyl, n-propyl, tert-butyl, phenyl, hydroxymethyl, carboxyl, ethoxycarbonyl, cyano, amino, hydrazino, nitro, azido, chloro, bromo and iodo groups as substituents on the ring carbon atoms.
42 citations
TL;DR: Among the compounds tested, 5-n-tridecylpyrazole-3-carboxylic acid (5k) exhibited the most favorable spectrum of activity and was as effective as clofibrate and is now undergoing further pharmacological evaluation.
Abstract: A series of 5-alkylpyrazole derivatives was synthesized and evaluated for potent hypolipidemic activity in rats. Many pyrazole derivatives with an alkyl group at the 5 position of the pyrazole ring were found to possess high hypolipidemic activity. Homologation of the alkyl chain led to marked increase in activity, but introduction of other substituents at other sites on the pyrazole ring failed to enhance the activity. In addition, the replacement of the pyrazole ring with an isoxazole ring resulted in a marked decrease in activity. Among the compounds tested, 5-n-tridecylpyrazole-3-carboxylic acid (5k) exhibited the most favorable spectrum of activity and was as effective as clofibrate. This compound, 5k, showed fairly low toxicity in an acute test (LD50=10.0g/kg) and hence is now undergoing further pharmacological evaluation.
35 citations
TL;DR: Microsomes isolated from rats treated for 3 days with 200 mg/kg body wt.
34 citations
TL;DR: In this paper, the reaction of 1-(2,6-dichlorobenzoyl)-4-methylpyrazole gave 5-alkenyl-substituted pyrazole.
Abstract: Treatments of 1-(2,6-dichlorobenzoyl)-, 3-acetyl-1-(2,6-dichlorobenzoyl)-, 1-(2,6-dichlorobenzoyl)-2-formyl-, and 1-(phenylsulfonyl)pyrroles with palladium acetate and alkyl acrylates gave the corresponding α-alkenyl-substituted pyrroles in good yields, while the reaction of 1-(2,6-dichlorobenzoyl)-2,5-dimethylpyrrole gave small amounts of β-alkenyl-substituted pyrroles. Under similar conditions, 1-(2,6-dichlorobenzoyl)pyrazole and 1-(2,6-dichlorobenzoyl)-3,5-dimethylpyrazole reacted with palladium acetate and alkyl acrylates to give the corresponding 4-alkenyl-substituted pyrazoles. The reaction of 1-(2,6-dichlorobenzoyl)-4-methylpyrazole gave 5-alkenyl-substituted pyrazole
31 citations
TL;DR: In this article, the title compound (abbreviated as MPzATSH) has been synthesised and physico-chemically (IR, PMR and mass spectrum) characterised for the first time.
31 citations
Journal Article•
TL;DR: In this article, the 3-methyl pyrazole-1-y1)-1,5(7)-dimethyl pyrazabole was characterized by NMR data.
Abstract: : The reaction of KBH4 with Hpzme (= 3-methylpyrazole) can be directed to yield K(H2B(pzme)2), K(HB(pzme)3), or K(B(pzme)4), respectively, depending on the experimental conditions. All three salts are sterochemically pure with the methyl group being located exclusively in the 3-position of the pyrazole ring. In contrast, reaction of (CH3)3NBH3 with Hpzme yields a mixture of 1,5- and 1,7-dimethylpyrazabole. Similarly, reaction of K(H2B(pzme)2) with (CH3)3NBH2I produces a mixture of 1,5- and 1,7-dimethylpyrazabole, suggesting at least two different pathways for the latter process. In addition, the compounds 4,4,8,8-tetrabromo- and 4,4,8,8-tetrakis(3-methylpyrazole-1-y1)-1,5(7)-dimethylpyrazabole were also prepared. all compounds were characterized by NMR data.
27 citations
TL;DR: The chemical shifts and coupling constants of [1,2-15N2] pyrazole, 2-(1, 2- 15N2]-pyrazolyl)-2-[l, 3-2H6]propanol, 1-nitro[1,215N 2] and 3-nitrogen[ 1,2 -15N 2 ]pyrazole are reported in this paper.
Abstract: The chemical shifts and coupling constants of [1,2-15N2]pyrazole, 2-(1-[1,2- 15N2]pyrazolyl)-2-[l,3-2H6]propanol, 1-nitro[1,215N2] and 3-nitro[1,2-15N2]pyrazole are reported.
26 citations
TL;DR: In this paper, the reaction of 2-cyanoethanoic acid hydrazide and arylidenemalononitrile was studied as a new route for the synthesis of N-amino-2-pyridones.
25 citations
TL;DR: In this article, the synthesis and characterization of transition-metal co-ordination compounds containing the newly synthesized ligand NN-bis(3,5-dimethylpyrazol-1-ylmethyl)aminoethane (bdmpae) are described.
Abstract: The synthesis and characterization of transition-metal co-ordination compounds containing the newly synthesized ligand NN-bis(3,5-dimethylpyrazol-1-ylmethyl)aminoethane (bdmpae) are described. The compounds have the general formulae [M(bdmpae)X2](M = Co, Ni, Cu, or Zn; X = Cl, Br, or NO3) and [M(bdmpae)2][ClO4]2(M = Co or Ni). The compounds have been characterized by spectroscopic measurements and conductivity studies in solution. In most compounds the ligand behaves as a chelating tridentate ligand. In the mono-adducts the co-ordination around the metal ions is completed by two anions, resulting in a five-co-ordinate geometry (X = Cl or Br) or a six-co-ordinate geometry (X = NO3; in this case one nitrate is monodentate and the other is bidentate). The bis-adducts appear to have distorted octahedral co-ordination geometries for the metal ions. To prove the chelating nature of the ligand, and in particular the co-ordination of the amine nitrogen, the X-ray structure of one representative example was undertaken. Crystals of [Ni(bdmpae)(NO3)2] are of space group P21/c, with a= 8.511(3), b= 14.103(3), c= 15.865(8)A, β= 92.75(3)°, and Z= 4. Standard least-squares refinements resulted in R= 0.041 (R′= 0.059). The nickel atom has a NiN3O3(mer) chromophore in a distorted octahedral geometry. One nitrate group is monodentate [Ni–O 2.052(5)A], whereas the other is bidentate [Ni–O 2.157(5) and 2.145(5)A]. Ni–N distances are 2.061 (5) and 2.034(5)A for the pyrazole nitrogens and 2.128(5)A for the amine nitrogen.
23 citations
TL;DR: This report is the first on the use of pyrazole to augment selective oxidation by a chronium (VI) reagent.
Abstract: ABASTRACT: This paper presents a modified method for the selective oxidation of allylic alchols. Pyrazole, when used with pyridinium chlorochromate, is a mild and useful reagent system for the rapid and selective oxidation of steroidal allylic alcohols to the corresponding α, β-unsaturated ketones. The reaction of each substrate was carried out by adding the oxidant to a dry methylene chloride solution containing pyrazole and an allylic alchol. This report is the first on the use of pyrazole to augment selective oxidation by a chronium (VI) reagent.
Journal Article•
TL;DR: Results were obtained with combinations which included F-ara-A, hydroxyurea, and Desferal, suggesting that ribonucleotide reductase was an intracellular site of action and synergistic inhibition of L1210 cell growth was obtained.
Abstract: 9-β-d-Arabinofuranosyl-2-fluoroadenine (2-F-ara-A) and 2-fluoro-2′-deoxyadenosine (2-FdAdo) were potent inhibitors of L1210 cell growth in culture. Even though these 2-fluoroadenine nucleosides are very poor substrates for adenosine deaminase, erythro-9-(2-hydroxyl-3-nonyl)adenine potentiated the growth-inhibitory properties of 2-FdAdo but not 2-F-ara-A in a synergistic manner. 2-FdAdo and 2-F-ara-A inhibited the conversion of [3H]cytidine to deoxycytidine nucleotides and incorporation into DNA, suggesting that ribonucleotide reductase was an intracellular site of action. 2-F-ara-A (6 µm) in combination with 2,3-dihydro-1 H -pyrazole[2,3- a ]imidazole gave synergistic inhibition of L1210 cell growth. At lower concentrations of 2-F-ara-A, the inhibition by this combination was only additive. The addition of Desferal to the combination of 2-F-ara-A plus 2,3-dihydro-1 H -pyrazole[2,3- a ]imidazole provided a strong synergistic combination. Similar results were obtained with combinations which included F-ara-A, hydroxyurea, and Desferal. The combinations of 2-FdAdo plus 2,3-dihydro-1 H -pyrazole[2,3- a ]imidazole or hydroxyurea gave strong synergistic inhibition of L1210 cell growth, even at the lowest concentration of 2-FdAdo (0.6 µm) studied. The presence of Desferal in the combination served to further potentiate the synergism.
TL;DR: A plot of pKa values for eleven azoles and benzazoles vs the experimental ionization energy of the nitrogen lone pair shows the existence of three groups of compounds: simple unsubstituted azoles, pyrazole, oxazole, isoxazole and benzoxazoles carrying a methyl group α- to the basic centre.
TL;DR: In this paper, the coordinating behavior of the thiosemi-carbazone has been investigated by isolation and characterization of its complexes with Co(III), Ni(II), and Cu(II) having different counterions, Magnetic and spectral data indicate Co(MPzAP) 2X (X = counter ion) as spin paired octahedral species with the ligand in the deprotonated thiol form.
Abstract: The title compound (abbreviated as IIPzAPH) has been synthesised and physico-chemically (IR, PMR, mass spectra) characterized for the first time. The coordinating behaviour of the thiosemi-carbazone has been investigated by isolation and characterization of its complexes with Co(III), Ni(II) and Cu(II) having different counterions, Magnetic and spectral data indicate Co(MPzAP) 2X (X = counter ion) as spin paired octahedral species with the ligand in the deprotonated thiol form, while Ni(MPzAPH) 2X2 and Cu(MPzAPH) X2 are proposed to be spin-free octahedral with the ligand in the neutral thione form. A spin-paired diamagnetic Ni(MPzAP) (SCN) has also been identified. IR data point out that the pyrazolyl ring nitrogen (tertiary), the azomethine nitrogen and the sulphur atom are the points of attachment with the metal ion in all these complex species.
TL;DR: Shift comparisons with zinc-pyrazole complexes indicate a high degree of inner-sphere coordination of the pyrazole N2 to the active-site zinc in the ternary complex.
Abstract: The structures of the liver alcohol dehydrogenase
(LADH)-NAD^+-pyrazole and LADH-NAD+-4-ethylpyrazole complexes were investigated by ^(15)N nuclear magnetic resonance (NMR) spectroscopy. ^(15)N chemical shifts were
obtained for ^(15)N-labeled inhibitors and ^(15)N-labeled coenzyme bound in the ternary enzyme complexes. The structures of the two inhibitor complexes appear to be very similar. ^(15)N NMR studies of model pyrazole-zinc chloride complexes were carried out to determine the effect of zinc complexation on pyrazole chemical shifts. The N1 nicotinamide chemical shift of the coenzyme of the LADH-NAD^+-pyrazole complex demonstrates that NAD^+ is converted to a dihydronicotin amide derivative in the complex. The N1 chemical shift of the pyrazole in the ternary complex is consistent with covalent bond formation between pyrazole N1 and the nicotinamide ring of the coenzyme. The N2 chemical shift of the pyrazole in the ternary complex indicates that the nucleus of this nitrogen is about 40 ppm more shielded than those of the N2 nitrogens of typical pyrazoles. Such shielding is expected as the result of direct complexation of N2 to the active-site zinc. Shift comparisons with zinc-pyrazole complexes indicate a high degree of inner-sphere coordination of the pyrazole N2 to the active-site zinc in the ternary complex.
Patent•
13 Dec 1984TL;DR: The 3-aminopyrazolo [3,4-d]pyrimidine derivatives represented by the general formula (I) wherein R, and R2 each independently represent an aliphatic hydrocarbon group; R3 and R4 each represent hydrogen, alkyl, alkoxy carbonyl or formyl; and the dotted line designates the presence of two double bonds on the pyrazole ring.
Abstract: Novel 3-aminopyrazolo [3,4-d]pyrimidine derivatives represented by the general formula (I) wherein R, and R2 each independently represents an aliphatic hydrocarbon group; R3 and R4 each independently represents hydrogen, alkyl or acyl; R, is alkyl, alkoxycarbonyl or formyl; and the dotted line designates the presence of two double bonds on the pyrazole ring, to which R, is linked at either the 1-or 2- position and their salts, are useful for antiinflammatory, analgesic and antipyretic agents.
TL;DR: In this paper, a novel rearrangement reaction for 4-pyridazinylmethanols was described, and the precursors of the C-4 substituted pyrazole derivatives 8a and 8b were described.
Patent•
05 Nov 1984TL;DR: In this paper, the authors describe the derivatives of EP01518661,5-disubstituted-1H-pyrazole-4-carboxamide derivatives, useful as herbicides and aquatic algicides.
Abstract: of EP01518661,5-Disubstituted-1H-pyrazole-4-carboxamide derivatives, useful as herbicides and aquatic algicides.
TL;DR: In this paper, Amino-4-cyano-3-phenyl-4,5,6,7-tetrahydro-5-oxopyrazolo-[1,5-a]-pyrimidine derivatives were obtained.
Abstract: 5-Amino-4-cyano-3-phenylpyrazole (1) reacts with acrylonitrile or ethyl acrylate to yield 4-cyano-3-phenyl-4,5,6,7-tetrahydro-5-oxopyrazolo-[1,5-a]-pyrimidine (2). With urea, thiourea and ethyl acetoacetate1 gives the pyrazolopyrimidine derivatives6a,6b, and7 respectively. On the other hand, compound1 reacted with benzoylisothiocyanate to give the corresponding thiourea derivative4. Diazotized1 was coupled with malononitrile and ethyl cyanoacetate to yield the pyrazolopyrimidine derivatives10 and11, respectively, whereas on coupling with α-chloro acetoacetic ester and with acetylacetone the hydrazones12 and13 were obtained.
TL;DR: Amino-3(5)-cyano-5(3)-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)pyrazole (10) was converted into the diazopyrazole by treatment with nitrous acid as discussed by the authors.
Abstract: 4-Amino-3(5)-cyano-5(3)-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)pyrazole (10) was converted into the diazopyrazole (11) by treatment with nitrous acid. On photolysis in aqueous dioxane using visible light compound (11) gave 3(5)-cyano–5(3)-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)pyrazole (12)[48% from (10)] which formed the corresponding amide (13)(75%) with alkaline hydrogen peroxide. Deprotection of compound (13) with methanolic ammonia afforded 3(5)-carbamoyl-5(3)-β-D-ribofuranosylpyrazole (4)(74%), the 4-deoxy analogue of pyrazofurin (3).3(5)-Cyano-4-nitro-5(3)-(2,3,5-tri-O-acetyl-β-D-ribofuranosyl)pyrazole (1) reacted with dihydropyran and toluene-p-sulphonic acid to give the N-tetrahydropyranyl derivative (21)(66.5%). Hydrolysis of the nitrile group of compound (21), using alkaline hydrogen peroxide, afforded the amide (22)(71%) which was deprotected to give 3(5)-carbamoyl-4-nitro-5(3)-β-D-ribofuranosylpyrazole (23)(83%). Catalytic reduction of compound (23) gave 4-amino-3(5)-carbamoyl-5(3)-β-D-ribofuranosylpyrazole (5)(83%) which could be converted into formycin B (24)(69%).
Patent•
13 Sep 1984TL;DR: In this paper, the present invention is directed to herbicidal compounds of the formula STR1, where each R1 independently is halogen; R2 is halo or trifluoromethyl; and n is 1-5.
Abstract: The present invention is directed to herbicidal compounds of the formula ##STR1## wherein each R1 independently is halogen; R2 is halo or trifluoromethyl; and n is 1-5; with the provisos that when n is 1, R1 is other than fluorine, and when n is 2 and each R1 is chlorine, at least one R1 is located at a para or ortho position on the phenyl ring.
TL;DR: The synthesis of nitro-substituted meso-ionic compounds has been examined in an attempt to obtain analogues of the biologically active heterocycles (1) as discussed by the authors.
Abstract: The synthesis of nitro-substituted meso-ionic compounds has been examined in an attempt to obtain analogues of the biologically active heterocycles (1)–(3). The synthesis of the compounds (4) and (5) has been achieved but their instability precluded biological evaluation. The synthesis of the type-B meso-ionic heterocycle (6) was not successfully completed, but unusual nucleophilic displacement reactions of the pyrazole (13)→(16)+(17) and the pyrazolium salt (14)→(15) are reported.
TL;DR: In this paper, the cyclic voltammetric behavior of the (NH3)5 RuL3+/2+, (CN)5FeL2-/3+ and (CN)-5RuL2/3-series of complexes L = an imidazole, a pyrazole or 4-aminopyridine is described in relation to the behavior of various saturated donors (H2O, NH3) and stronger π- acceptor ligands (pyrazine, pyridine).
Abstract: The cyclic voltammetric behavior of the (NH3)5 RuL3+/2+, (CN)5FeL2-/3+ and (CN)5RuL2-/3-series of complexes L = an imidazole, a pyrazole or 4-aminopyridine is described in relation to the behavior of various saturated donors (H2O, NH3) and stronger π- acceptor ligands (pyrazine, pyridine). The influence of σ-donation, π-acceptor character and π-donor ability result in E1/2 values that become more positive with increasing π-acceptor character. The influence of σ-donation and π-donation is rather minimal in spite of the marked influence of the properties on the LMCT spectra of the M(III) complexes of the same series and the Mossbauer spectra for (CN)5FeL2- in particular.
TL;DR: In the first systematic study of thiopyranopyridines in which the sulphur atom is separated from the pyridine ring by one carbon atom, the four isomeric enol esters were synthesized as discussed by the authors.
Abstract: In the first systematic study of thiopyranopyridines in which the sulphur atom is separated from the pyridine ring by one carbon atom, the four isomeric enol esters, ethyl 5-hydroxy-8H-thiopyrano[3,4-b]-pyridine-6-carboxylate (4b), ethyl 8-hydroxy-5H-thiopyrano[4,3-b]pyridine-7-carboxylate (5b), and ethyl 4-hydroxy-1H-thiopyrano[3,4-c]- and [4,3-c]pyridine-3-carboxylate (6b) and (7b), have been synthesised. Improved methods for the preparation of their pyridine precursors are described. With phenylhydrazine, the enol esters (4b)–(7b) give condensed pyrazole derivatives (15)–(18), which have dipolar structures; with hot mineral acid they undergo decarboxylative hydrolysis, to give the corresponding oxothiopyranopyridines (4a)–(7a).
TL;DR: In this paper, fused pyrazole derivatives were synthesized for new potent analgesic agents, such as 2-substituted-5-hydroxypyrazole (I) with COCH3 or CO2C2H5) acylacetates (II) gave mainly pyrazolo [1, 2-a] pyrazone-1, 5 (1H, 5H)-diones (III) but did not give III at all Thermal and photochemical isomerization of III gave V
Abstract: As a part of our search for new potent analgesic agents, novel fused pyrazole derivatives were synthesized The reaction of 2-substituted-5-hydroxypyrazole (I) with ethyl 2-substituted (for example COCH3 or CO2C2H5) acylacetates (II) gave mainly pyrazolo [1, 2-a] pyrazole-1, 5 (1H, 5H)-diones (III) On the other hand, similar reaction of I with diethyl benzoylmalonate gave mainly pyrazolo [5, 1-b] [1, 3] oxazin-5 (5H)-one (V) but did not give III at all Thermal and photochemical isomerization of III gave V Methanolysis of IIIa in the presence of LiOH occurred with retention of the 4-ethoxycarbonyl-5-pyrazolone ring and similar products (VIa and VIf) were obtained by methanolysis of Va and Vf, respectively Analgesic activities of the present new compounds were all inferior to that of aminopyrine
TL;DR: The X-ray structure of [RuH(pz)(cod)2pzH] reveals a semi-bridging hydride ligand [Ru(1) −H(1)/1.68(5)A, Ru(2)−H( 1)/2.05(6)A and Ru(1⋯Ru(2)/3.166(1/A] in an unsymmetrical dimer with the ruthenium atoms linked by two pyrazolyl ligands; 1H and 13C n.r
Abstract: The X-ray structure of [{RuH(pz)(cod)}2pzH](cod = cyclo-octa-1,5-diene, pzH = pyrazole) reveals a semi-bridging hydride ligand [Ru(1)–H(1) 1.68(5)A, Ru(2)–H(1) 2.05(6)A, Ru(1)⋯ Ru(2) 3.166(1)A] in an unsymmetrical dimer with the ruthenium atoms linked by two pyrazolyl ligands; 1H and 13C n.m.r. spectra show that this structure persists in solution.
Patent•
19 Dec 1984
Abstract: A selective gas separator composed essentially of a reaction product of copper compound with an imidazole, a pyrazole, a triazole and/or a tetrazole.
TL;DR: In this article, the bidentate ligands 3,3,5,5′-tetramethyl-4,4′-bi-1H-pyrazole (tmbpz) gave complexes with the formula MCl 2 (LL) (M = Co, LL = mbpz; M = Ni, LL= tmbPz, tmmbpZ, mBPz).
TL;DR: The activation energy for ring inversion of the 3H-1,2-diazepine 2-oxides, determined by variable-temperature 13H n.m.r. spectroscopy, was ca. 12 −16 kJ mol −1 lower than that for the parent diazepines as discussed by the authors.
Abstract: The oxidation of a range of monocyclic and fused 3H-1,2-diazepines (1a–d) with m-chloroperbenzoic acid gave the 2-oxides, e.g.(9)–(11). In one case the diazepine 2-oxide (5) rearranged readily at room temperature to give the 3-alkenyl-3H-pyrazole 2-oxide (16) in a ca. 1 : 1 equilibrium mixture with (5). The activation energy for ring inversion of the 3H-1,2-diazepine 2-oxides, determined by variable-temperature 13H n.m.r. spectroscopy, was ca. 12–16 kJ mol–1 lower than that for the parent diazepines.