Day: November 16, 2022

Shukla, J. P. published the artcileProtolytic equilibria of several 4-acyl-substituted 1-phenyl-3-methylpyrazol-5-ones in dioxane-water mixtures, Category: pyrazoles-derivatives, the main research area is ionization constant pyrazolone acyl derivative; solvent effect ionization acylpyrazolone; thermodn ionization acylpyrazolone; substituent effect ionization acylpyrazole.

Thermodn. proton ionization constants, pKa, of several 4-acyl-substituted pyrazol-5-ones I [R = CF3, Me, (CH2)4Me] were determined in various dioxane-water mixtures at 25 and 35 ± 0.1°. The pKa values were determined by glass-electrode potentiometry and refined by computer. Both extrapolation and least-squares methods were used to obtain pKa values in pure water. All three acyl derivatives are weak monoprotic acids with pKa values between 2.5 and 3.9, increasing in the order stated. The pKa values do not vary linearly with the reciprocal of the dielec. constant of the medium; however, a plot of pKa vs. the mole fraction of dioxane is linear at a given temperature Values of standard free energy, enthalpy, and entropy changes associated with their protolytic equilibrium were also calculated Temperature, medium and substituent effects are briefly discussed.

Journal of Physical Organic Chemistry published new progress about Enolization. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Category: pyrazoles-derivatives.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Janjic, Monika published the artcileA Simple Synthesis of 5-(2-Aminophenyl)-1H-pyrazoles, COA of Formula: C9H9N3, the main research area is aminophenylpyrazole multistep synthesis; pyrazole multistep aminophenyl synthesis; enamino ketone preparation cyclization hydrazine; nitrophenylpyrazole preparation hydrogenation.

A four-step synthesis of 1-substituted 5-(2-aminophenyl)-1H-pyrazoles as a novel type of histamine analog and versatile building blocks for further transformations was developed. The synthesis starts from com. available 2-nitroacetophenone, which is converted into the enamino ketone (E)-2-O2NC6H4COCH:CHNMe2 (I) as the key intermediate. Cyclization of the key intermediate (I) with monosubstituted hydrazines afforded the 5-(2-nitrophenyl)-1H-pyrazoles. Finally, catalytic hydrogenation of the nitro compounds furnished the title compounds in good yields. As demonstrated by some further transformations, addnl. functionalization of 5-(2-nitrophenyl)-1H-pyrazoles and 5-(2-aminophenyl)-1H-pyrazoles is feasible, either by electrophilic substitution at C(4) of the pyrazole ring, or at the NH2 group.

Helvetica Chimica Acta published new progress about Cyclization. 111562-32-4 belongs to class pyrazoles-derivatives, name is 2-(1H-Pyrazol-3-yl)aniline, and the molecular formula is C9H9N3, COA of Formula: C9H9N3.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Hassan, Alaa A. published the artcilePyrazole, pyrazolo[1,2-c]-1,3,4-thiadiazole and thiadiazepine derivatives from thiosemicarbazides, COA of Formula: C5H3N5, the main research area is thiosemicarbazide tetracyanoethene cyclization; pyrazole derivative preparation; pyrazolothiadiazole derivative preparation; thiadiazepine derivative preparation.

Thiosemicarbazides RNHCSNHNH2 [R = Ph, Bn, allyl] reacted with tetracyanoethene in Et acetate with admission of air to form the 7-amino-2-organylimino-2,3-dihydro-1,3,4-thiadiazepine-5,6-dicarbonitriles I [ R = Ph, Bn], 7-amino-1-organylimino-3-oxopyrazolo[1,2-c]-1,3,4-thiadiazole-5,5,6-tricarbonitriles II, 7-amino-1-organyl-iminopyrazolo[1,2-c]-1,3,4-thiadiazole-3,3,5,5,6-pentacarbonitriles III and 3-amino-1H-pyrazole-4,5-dicarbonitrile (IV) in moderate yields. Rationales for the observed conversations are presented.

ARKIVOC (Gainesville, FL, United States) published new progress about Cyclization. 54385-49-8 belongs to class pyrazoles-derivatives, name is 5-Amino-1H-pyrazole-3,4-dicarbonitrile, and the molecular formula is C5H3N5, COA of Formula: C5H3N5.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Gerecke, Max published the artcileNew tetracyclic derivatives of imidazo[1,5-a][1,4]benzodiazepines and of imidazo[1,5-a]thieno[3,2-f][1,4]diazepines, HPLC of Formula: 111562-32-4, the main research area is anxiolytic imidazobenzodiazepine imidazothienodiazepine preparation.

The synthesis of new tetracyclic 1,4-diazepine derivatives is described. In these compounds, an addnl. five-membered heterocycle is fused on the known tricyclic ring systems imidazo[1,5-a][1,4]benzodiazepine and imidazo[1,5-a]thieno[3,2-f][1,4]diazepine. Many of these new compounds display a very high affinity to the benzodiazepine receptor in mammals.

Heterocycles published new progress about Anxiolytics. 111562-32-4 belongs to class pyrazoles-derivatives, name is 2-(1H-Pyrazol-3-yl)aniline, and the molecular formula is C9H9N3, HPLC of Formula: 111562-32-4.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Sugiura, Masaaki published the artcileEffect of quaternary ammonium salts on carrier-mediated transport of lanthanide ions through cellulose triacetate membranes, Category: pyrazoles-derivatives, the main research area is lanthanide membrane transport quaternary ammonium; acetate cellulose membrane lanthanide transport; lanthanum transport cellulose acetate membrane; cerium transport cellulose acetate membrane; benzoylmethylphenylpyrazolone carrier membrane transport lanthanide; tfluoroacetylmethylphenylpyrazolone carrier membrane transport lanthanide; plasticizer quaternary ammonium salt membrane; nitrophenyloctyl ether plasticizer membrane.

Fluxes of all lanthanides, except Pm, across cellulose triacetate membranes were determined by using mixtures of o-nitrophenyl n-octyl ether and quaternary ammonium salts as plasticizers, and 4-benzoyl-3-methyl-1-phenyl-5-pyrazolone (I) and 4-trifluoroacetyl-3-methyl-1-phenyl-5-pyrazolone (II) as carriers. The quaternary ammonium salts used were didodecyldimethyl-, distearyldimethyl-, tetrahexyl-, tetraoctyl-, and tetradecylammonium bromides [referred to as (C12)2NBr, (C18)2NBr, (C6)4NBr, (C8)4NBr, and (C10)4NBr, resp.]. The effect of these quaternary ammonium bromides on the flux was demonstrated. For membranes containing 0.1 M (C12)2NBr and (C18)2NBr, I exhibited considerably high fluxes. The fluxes of La and Ce using I for (C12)2NBr were higher than those of the other lanthanides. For the membranes containing 0.5 M (C12)2NBr and 0.1 M (C18)2NBr, however, no difference in flux among the lanthanides was observed The fluxes using II for (C12)2NBr and (C18)2NBr were very small, with the exception of some lanthanides. Appreciably high fluxes were observed for membranes containing 0.1 M (C6)4NBr using I. For (C8)4NBr and (C10)4NBr, I exhibited low fluxes. For these membranes using II, the lanthanides were scarcely transported.

Separation Science and Technology published new progress about Plasticizers. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Category: pyrazoles-derivatives.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Khonde, Lutete Peguy published the artcile1,3-Diarylpyrazolyl-acylsulfonamides as Potent Anti-tuberculosis Agents Targeting Cell Wall Biosynthesis in Mycobacterium tuberculosis, Application In Synthesis of 166196-54-9, the main research area is diarylpyrazolyl acylsulfonamide preparation antituberculosis activity.

Phenotypic whole cell high-throughput screening of a ~150,000 diverse set of compounds against Mycobacterium tuberculosis (Mtb) in cholesterol-containing media identified 1,3-diarylpyrazolyl-acylsulfonamide I as a moderately active hit. Structure-activity relationship (SAR) studies demonstrated a clear scope to improve whole cell potency to MIC values of <0.5μM, and a plausible pharmacophore model was developed to describe the chem. space of active compounds Compounds are bactericidal in vitro against replicating Mtb and retained activity against multidrug-resistant clin. isolates. Initial biol. triage assays indicated cell wall biosynthesis as a plausible mode-of-action for the series. However, no cross-resistance with known cell wall targets such as MmpL3, DprE1, InhA, and EthA was detected, suggesting a potentially novel mode-of-action or inhibition. The in vitro and in vivo drug metabolism and pharmacokinetics profiles of several active compounds from the series were established leading to the identification of a compound for in vivo efficacy proof-of-concept studies. Journal of Medicinal Chemistry published new progress about Homo sapiens. 166196-54-9 belongs to class pyrazoles-derivatives, name is 4-(4-Bromo-1H-pyrazol-3-yl)pyridine, and the molecular formula is C8H6BrN3, Application In Synthesis of 166196-54-9.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Umetani, Shigeo published the artcileRole of the intramolecular hydrogen bond and ligand rigidity in the complexation of trifluoroacetylcycloalkanones with lanthanides: novel strategy for the design of organic ligands of high selectivity, Recommanded Product: 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, the main research area is intramol hydrogen bond ligand rigidity complexation; trifluoroacetylcycloalkanone lanthanide complexation extraction.

Trifluoroacetylcyclopentanone (1), -cyclohexanone (2) and -cycloheptanone (3) were synthesized and the complexation with lanthanides (La3+, Pr3+, Eu3+, Ho3+ and Yb3+) was studied via the solvent extraction technique. The strength of the intramol. hydrogen bond depends on the distance between the two donating oxygens in the enol form estimated by semi-empirical MNDO/H and ab initio calculations The O-O distance for 1 is larger than those for 2 and 3 as predicted from their cyclic structures. The strength of the intramol. hydrogen bond increases in the order, 1<2≈3, which is also supported by 1H NMR and IR spectra. The acid dissociation constants (pKa) were measured by potentiometric titration in 30 dioxane-water. The pKa values increase in the order, 1<2≤3, reflecting the strength of the intramol. hydrogen bond. Lanthanides were readily extracted by 1 owing to its strong acidity. However, better separation for lanthanides was achieved with 2 and 3. The extractability and separability were discussed in terms of the ligand rigidity and the intramol. hydrogen bond originating from the distance between the two donating oxygens. Inorganica Chimica Acta published new progress about Complexation. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Recommanded Product: 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Zhang, Anyun published the artcileAssociation Behavior of 4-Acylpyrazolone Derivative and Tertiary Amine of High Molecular Weight in Antagonistic Synergistic Extraction of Palladium, Computed Properties of 1691-93-6, the main research area is TOA hydrogen bond complexation fluoroacyl pyrazolone derivative spectrophotometry; palladium cation solvent extraction TOA fluoroacyl pyrazolone derivative spectrophotometry.

To find an effective extraction and removal method for palladium(II), which is one of the main fission products from an acidic nuclear spent fuel solution, the extraction behavior of palladium(II) from a nitric acid medium by an acidic chelating extractant, 1-phenyl-3-methyl-4-trifluoroacetylpyrazolone-5-one (HPMTP) and a tertiary amine of high mol. weight, tri-n-octylamine (TOA), has been studied by spectrophotometry. A noticeable antagonistic extraction effect was observed in the extraction system under the given conditions. To understand this phenomenon, a preliminary investigation was performed to explain the mechanism of this reaction. According to the theory of corresponding solutions (TCS), the association reaction between HPMTP and TOA is proposed in the organic phase. An associated species, HPMTP·TOA, formed through hydrogen bonding in a chloroform medium might be the main reason why an antagonistic extraction effect occurred. The association constant between HPMTP and TOA was calculated to be 2.86 ± 0.05.

Journal of Solution Chemistry published new progress about Complexation. 1691-93-6 belongs to class pyrazoles-derivatives, name is 5-Methyl-2-phenyl-4-(2,2,2-trifluoroacetyl)-1H-pyrazol-3(2H)-one, and the molecular formula is C12H9F3N2O2, Computed Properties of 1691-93-6.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Fu, Lili published the artcileSynthesis of sulfonamides from azoles and sodium sulfinates at ambient temperature, Name: 4-Bromo-1-tosyl-1H-pyrazole, the main research area is oxidative amination azole sodium sulfinate NBS NIS sulfonamide synthesis; sulfur nitrogen bond formation azole sodium sulfinate.

NBS or NIS mediated direct S-N bond formation between azoles and sodium sulfinates is described. The reaction shows good substrate scope and tolerates a wide range of functionalities in both azoles and sodium sulfinate substrates. Pyrazoles are also suitable for this method, various 4-halopyrazoles derivatives were obtained by using N-halosuccinimide (NXS) as the halogen source. Thus, e.g., oxidative amination of benzimidazole with sodium p-tolylsulfinate using NBS as oxidant in 1,4-dioxane afforded 1-tosylbenzimidazole (93%).

Tetrahedron published new progress about Atom economy. 116228-41-2 belongs to class pyrazoles-derivatives, name is 4-Bromo-1-tosyl-1H-pyrazole, and the molecular formula is C10H9BrN2O2S, Name: 4-Bromo-1-tosyl-1H-pyrazole.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics

Omar, Mohamed T. published the artcileA new synthetic route to 3-oxo-5-phenyl-2,3-dihydropyrazoles, Safety of 5-Phenyl-1H-pyrazol-3(2H)-one, the main research area is pyrazolone phenyl; phenylpyrazolone; hydrazine benzylidenethiazolidinedione rearrangement.

The reaction of RNHNH2 (R = H, Me) with benzylidenethiazolidinediones I (R1 = PhCH2, Et, allyl) gave the resp. pyrazolones II. I (R1 = PhCH2) was heated with PhNHNH2 in EtOH to give II (R = Ph) and addition product III; a mixture of III, pyridine, Et3N, and EtOH was refluxed 4 h to give II (R = Ph).

Synthesis published new progress about Rearrangement. 27412-71-1 belongs to class pyrazoles-derivatives, name is 5-Phenyl-1H-pyrazol-3(2H)-one, and the molecular formula is C9H8N2O, Safety of 5-Phenyl-1H-pyrazol-3(2H)-one.

Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics