Category: pyrazoles-derivatives

Beyer, Hans published the artcileThiazoles. XXIX. The condensation products of thiosemicarbazide with ethyl α-chloroacetoacetate and a novel ring contraction of 2-amino-5-methyl-6-carbethoxy-1,3,4-thiadiazine to 3-methyl-4-carbethoxy-5-aminopyrazole, Synthetic Route of 23286-70-6, the publication is Chemische Berichte (1956), 1652-8, database is CAplus.

On condensation of AcCHClCO₂Et (I) with H₂NNHCSNH₂ (II), 4-methyl-5-carbethoxy-2-thiazolylhydrazine (III), MeC(:NNHCSNH₂)CHClCO₂Et (IV), or 3-amino-4-methyl-5-carbethoxy-2-thiazolone imide (V) is formed, depending upon the pH and temperature Refluxing 13.3 g. 1-acetylthiosemicarbazide and 8.5 g. NaOAc in 75 cc. absolute EtOH in a CO₂ atm., adding dropwise within 15 min. 16.5 g. I in 25 cc. absolute EtOH, and refluxing the mixture another hr. yield 96% N’-acetyl-N-(4-methyl-5-carbethoxy-2-thiazolyl)hydrazine (VI), fine needles, m. 227°, which (12.2 g.), refluxed in 75 cc. absolute EtOH 1 hr. with 5.3 cc. concentrated HCl, gives 88% III.HCl, needles, m. 189-90°. III.HCl is also formed in 80% yield when 4.1 g. I in 3 cc. EtOH is added (15 min.) to 2.28 g. II in 20 cc. EtOH at 50° (free III, liberated with NaOAc, 100%, leaflets, m. 186°; di-Ac derivative, prepared by heating 2.01 g. III or 2.43 g. VI with 15 cc. Ac₂O 20 min. on a water bath, 84%, needles, m. 198°; tri-Ac derivative, prepared by heating 2.01 g. III 15 min. in 10 cc. Ac₂O containing 5 drops concentrated H₂SO₄, prisms, m. 131°; monoformyl derivative, prepared by refluxing 2.01 g. III 1 hr. with 10 cc. 98% HCO₂H, 92%, fine needles, m. 205°). Boiling 2.01 g. III 15 min. in 25 cc. Me₂CO yields 92% acetone (4-methyl-5-carbethoxy-2-thiazolyl)hydrazone, silky needles, m. 143°; PhCOMe derivative, 95%, m. 118°. Adding dropwise (1 hr.) 16.4 g. I to 9.1 g. II in 50 cc. 2N HCl at 0° yields 100% IV, also formed in 78% yield by mixing the 2 reagents in alc. solution without HCl; IV decompose on storage. Adding at 70° 9.5 g. IV to 60 cc. PrOH and bringing the mixture quickly to the boil give 74% 2-amino-5-methyl-6-carbethoxy-1,3,4-thiadiazine-HCl, decompose about 90° [free base (VII), liberated with saturated NaOAc solution, fine yellow needles, decompose above 80°; after 2-3 days it decompose with the formation of 3-methyl-4-carbethoxy-5-aminopyrazole (VIII)]. Heating VII or IV with the calculated amount of p-O₂NC₆H₄CHO (IX) in EtOH yields 40% IX (4-methyl-5-carbethoxy-2-thiazolyl)hydrazone, yellow needles, m. 244°; BzH analog, pale yellow leaflets, m. 189°, is prepared by treating III.HCl in 2N HCl with BzH and NaOAc, or in 93% yield by condensation of equimolar amounts of III and BzH. Heating 7.2 g. VII.HCl in 50 cc. concentrated HCl 15-20 min. on a water bath and concentrating the filtered solution to 1/3 its volume yield 66% V.HCl, fine needles, m. 242-4° (decomposition), which is also formed in 43% yield when 8.2 g. I is added to 4.6 g. II in 30 cc. hot concentrated HCl and the solution concentrated to 0.5 its volume (free V, needles, m. 130°; di-Ac derivative, prisms, m. 107-8°). Adding 1.28 g. NaNO₂ in H₂O to 2.4 g. V.HCl in 25 cc. 2N HCl at 0° and pouring the ice-cooled solution into 1.2 g. PhNMe₂ in dilute HCl give 2-(p-dimethylaminophenylazo)-4-methyl-5-carbethoxythiazole (X).HCl, deep blue crystals, from which NH₄OH liberates the free X, red-brown leaflets, m. 205°; X is also obtained in 43% yield when 3.7 g. 2-amino-4-methyl-5-carbethoxythiazole is diazotized at 0° and the diazonium solution is treated with 2.4 g. PhNMe₂. Refluxing 9.5 g. VII.HCl 1 hr. in 50 cc. 2N alc. HCl and filtering off the S formed yield 80% VIII.HCl, m. 187-9° [free base, leaflets containing 1 mole H₂O, m. 69°, m. 113° (H₂O-free); nitrate, prisms, m. 197-8° (decomposition); mono-Ac derivative, prisms, m. 91°]. Treating 4.1 g. VIII.HCl in 15 cc. H₂O and 3 cc. concentrated HCl at 0° with 1.38 g. NaNO₂ in 7 cc. H₂O, pouring the diazonium solution into ice cold 30% H₃PO₂, keeping the mixture overnight at 0°, and adding saturated NaOAc solution give 3-methyl-4-carbethoxypyrazole-H₂O, m. 46° (HCl salt, needles, sinters 145°, m. 160°). Diazotizing 2.5 g. VIII.HCl, adding the diazonium solution to 1.2 g. PhNMe₂ in dilute HCl, and then adding NaOAc give 70% 3-methyl-4-carbethoxy-5-(p-dimethylaminophenylazo)pyrazole, stout orange prisms, m. 172°.

Chemische Berichte published new progress about 23286-70-6. 23286-70-6 belongs to pyrazoles-derivatives, auxiliary class Pyrazole,Amine,Ester, name is Ethyl 5-amino-3-methyl-1H-pyrazole-4-carboxylate, and the molecular formula is C7H11N3O2, Synthetic Route of 23286-70-6.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Hynes, John Jr. published the artcileDiscovery of potent and efficacious pyrrolopyridazines as dual JAK1/3 inhibitors, Application In Synthesis of 724710-02-5, the publication is Bioorganic & Medicinal Chemistry Letters (2017), 27(14), 3101-3106, database is CAplus and MEDLINE.

A series of potent dual JAK1/3 inhibitors have been developed from a moderately selective JAK3 inhibitor. Substitution at the C6 position of the pyrrolopyridazine core with aryl groups provided exceptional biochem. potency against JAK1 and JAK3 while maintaining good selectivity against JAK2 and Tyk2. Translation to in vivo efficacy was observed in a murine model of chronic inflammation. X-ray co-crystal structure determination confirmed the presumed inhibitor binding orientation in JAK3. Efforts to reduce hERG channel inhibition will be described.

Bioorganic & Medicinal Chemistry Letters published new progress about 724710-02-5. 724710-02-5 belongs to pyrazoles-derivatives, auxiliary class Pyrazole,Boronic acid and ester,Pyrazole,Boronic Acids,Boronic acid and ester, name is (1H-Pyrazol-5-yl)boronic acid, and the molecular formula is C3H5BN2O2, Application In Synthesis of 724710-02-5.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Liu, Deng-Feng published the artcileRing-opening copolymerization of CHO and MA catalyzed by mononuclear [Zn(L²)(H₂O)] or trinuclear [Zn₃(L²)₂(OAc)₂] complex based on the asymmetrical bis-Schiff-base ligand precursor, Application of 4-Benzoyl-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, the publication is Journal of Molecular Catalysis A: Chemical (2014), 136-145, database is CAplus.

Based on the half-unit Schiff-base ligand precursor HL¹ and the asym. bis-Schiff-base ligand precursor H₂L² synthesized from the reaction of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (PMBP), o-phenylenediamine and/or o-vanillin, three complexes containing low toxicity Zn²⁺ ions, mononuclear [Zn(L¹)₂] (1), [Zn(L²)(H₂O)] (2) and trinuclear [Zn₃(L²)₂(OAc)₂] (3), are obtained, resp. Complex 1 proves to be inactive, resulting from its saturated octahedral coordination environment around the central Zn²⁺ ion, while in complex 2 or 3, the unsaturated five and/or four-coordinate coordination environment for the catalytic active centers (Zn²⁺ ions) permits the monomer insertion for the effective bulk or solution copolymerization of CHO (cyclohexene oxide) and MA (maleic anhydride). All the bulk copolymerizations afford poly(ester-co-ether)s, while some of the solution copolymerizations produce perfectly alternating polyester copolymers. Moreover, higher polymerization temperature, lower catalyst and co-catalyst concentration and shorter reaction time are helpful for the formation of alternating copolymers in bulk or solution copolymerization Of the three co-catalysts, DMAP (4-(dimethylamino)pyridine) is found to be the most efficient, while an excess thereof is detrimental for chain growth of the copolymers.

Journal of Molecular Catalysis A: Chemical published new progress about 4551-69-3. 4551-69-3 belongs to pyrazoles-derivatives, auxiliary class Benzenes, name is 4-Benzoyl-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, and the molecular formula is C17H14N2O2, Application of 4-Benzoyl-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Yan, Xingchen published the artcileCrystal structures and theoretical calculations of two peculiar compounds derived from 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one, Product Details of C17H14N2O2, the publication is Journal of Molecular Structure (2014), 609-616, database is CAplus.

A potassium coordination polymer [K₂(PMBP)₂(H₂O)₃]_n·2nH₂O (1) was prepared by reaction of 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one (HPMBP) with potassium hydroxide. The single crystal of the supermol. C₆H₁₁NH⁺₃·PMBP^– (2) was then obtained by utilizing cyclohexylamine as the proton acceptor. It is a diketonate salt with an organic base where the PMBP^– anions are stabilized by the intermol. weak interactions (including hydrogen bonding, π-π stacking interactions and Van der Waals forces), rather than by coordination to a metal center. Geometrical parameters of the isolated PMBP^– anion were optimized through quantum chem. calculation to simulate the state without any disturbances or interactions. Comparison of geometric parameters of compound 1 with the optimized structure of PMBP^– provides an approach to study weak intermol. interactions in the crystal state. The coordination sites and the proton acceptors of hydrogen bonds predicted by theor. calculations are consistent to the exptl. results.

Journal of Molecular Structure published new progress about 4551-69-3. 4551-69-3 belongs to pyrazoles-derivatives, auxiliary class Benzenes, name is 4-Benzoyl-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, and the molecular formula is C19H15NO3, Product Details of C17H14N2O2.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Yi, Rong-Nan published the artcileGreen synthesis of 4-organylselanyl-1H-pyrazoles through electrochemical cross-dehydrogenative coupling of 1H-pyrazoles and diorganyl diselenides, Application In Synthesis of 930-36-9, the publication is Tetrahedron Letters (2021), 153257, database is CAplus.

An atom-economical and efficient method for synthesizing 4-organylselanyl-1H-pyrazoles through electrochem. cross-dehydrogenation coupling of N-unsubstituted pyrazoles with diorganyl diselenides under chem. oxidant-free and mild conditions was developed. This reaction not only shows good functional-group tolerance but also has high scalability.

Tetrahedron Letters published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C15H20O6, Application In Synthesis of 930-36-9.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Conroy, Nathan A. published the artcileA Novel Method for Tracer Concentration Plutonium(V) Solution Preparation, Synthetic Route of 4551-69-3, the publication is Analytical Chemistry (Washington, DC, United States) (2016), 88(8), 4196-4199, database is CAplus and MEDLINE.

Preparation of relatively pure low concentration Pu(V) solutions for environmental studies is nontrivial due to the complex redox chem. of Pu. Ozone gas generated by an inexpensive unit designed for household-use was used to oxidize a 2 × 10^-8 M Pu(IV) solution to predominantly Pu(VI) with some Pu(V) present. Over several days, the Pu(VI) in the solution reduced to Pu(V) without further reducing to Pu(IV). The reduction from Pu(VI) to Pu(V) could be accelerated by raising the pH of the solution, which led to an immediate conversion without substantial conversion to Pu(IV). The aqueous Pu is stable as predominately Pu(V) for greater than one month from pH 3-7; however, at circumneutral pH, a sizable fraction of Pu was lost from solution by either precipitation or sorption to the vial walls. This method provides a fast means of preparing Pu(V) solutions for tracer concentration studies without numerous extraction or cleanup steps.

Analytical Chemistry (Washington, DC, United States) published new progress about 4551-69-3. 4551-69-3 belongs to pyrazoles-derivatives, auxiliary class Benzenes, name is 4-Benzoyl-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, and the molecular formula is C17H14N2O2, Synthetic Route of 4551-69-3.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Fillion, Joseph J. published the artcilePhase Transitions, Decomposition Temperatures, Viscosities, and Densities of Phosphonium, Ammonium, and Imidazolium Ionic Liquids with Aprotic Heterocyclic Anions, HPLC of Formula: 930-36-9, the publication is Journal of Chemical & Engineering Data (2016), 61(8), 2897-2914, database is CAplus.

Ionic liquids (ILs) with aprotic heterocyclic anions (AHAs) have been developed primarily for CO₂ capture applications. However, they have also been considered for cofluid CO₂/IL vapor compression refrigeration cycles and for various electrochem. applications. In all of these cases, reducing the viscosity of the IL is of primary importance. Therefore, the focus of this work is tuning the cation to produce AHA ILs with both low viscosities and low m.ps. Toward this goal we have synthesized 40 AHA ILs paired with phosphonium, ammonium and imidazolium cations, as well as a number of ILs with the bis(trifluoromethylsulfonyl)imide anion to use for comparison. The azolide anions investigated were 2-cyanopyrrolide, 4-nitropyrazolide, various substituted imidazolides, 1,2,3-triazolide, and tetrazolide. M.ps., glass transition temperatures, and decomposition temperatures were measured for all ILs. Viscosities and densities were measured from 278.15 to 343.15 K and 283.15 to 353.15 K, resp., for all ILs except those with high m.ps. or excessively high viscosities. Shortening the alkyl chains on tetra-alkylphosphonium and tetra-alkylammonium cations reduces viscosity, but eventually results in unacceptably higher m.ps. For equivalent alkyl chain lengths and anions, ammoniums have higher m.ps. and lower decomposition temperatures than phosphoniums. The introduction of an ether chain on a phosphonium cation lowers viscosity but reduces thermal stability. Di- and trialkylimidazolium with sufficiently low m.ps. have relatively high viscosities.

Journal of Chemical & Engineering Data published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, HPLC of Formula: 930-36-9.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Zhang, Qingwei published the artcileHit to Lead optimization of a novel class of squarate-containing polo-like kinase inhibitors, COA of Formula: C3H5BN2O2, the publication is Bioorganic & Medicinal Chemistry Letters (2012), 22(24), 7615-7622, database is CAplus and MEDLINE.

Aminodioxocyclobutenylamino pyrimidineamines (aminopyrimidine squaramides) such as I, derived from a squaramide identified through high-throughput screening, were prepared as selective Polo-like kinase 1 (Plk1) inhibitors for potential use as antitumor agents. Using mol. modeling and extensive structure-activity studies, I (Plk1 K_i = 5 nM; EC₅₀ = 1.05 μM) was identified; its inhibition of Plk1 and of a panel of kinases, its lipophilicity, and its pharmacokinetics were determined I demonstrated moderate efficacy at dosages of 100 mg/kg in a murine pancreatic cancer xenograft tumor model and no overt toxicity.

Bioorganic & Medicinal Chemistry Letters published new progress about 763120-58-7. 763120-58-7 belongs to pyrazoles-derivatives, auxiliary class Pyrazole,Boronic acid and ester,Boronic Acids,Boronic acid and ester, name is 1H-Pyrazole-4-boronic acid, and the molecular formula is C9H17NO, COA of Formula: C3H5BN2O2.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Caldwell, John J. published the artcileDesign and synthesis of 2(1H)-pyrazinones as inhibitors of protein kinases, Category: pyrazoles-derivatives, the publication is Tetrahedron (2012), 68(47), 9713-9728, database is CAplus.

Kinase enzymes play a key role in the development and progression of cancer. Inhibitors of deregulated kinases are effective small mol. anticancer drugs. The 2(1H)-pyrazinone heterocycle is a previously unexploited motif that can fulfil the structural requirements for ATP-competitive inhibition of kinases. Rapid solution-phase syntheses of novel 3,5- and 3,6-disubstituted-2(1H)-pyrazinones were developed through selective, sequential substitution of 2,5-dihalo-3-benzyloxypyrazine and 3,5-dihalo-2(1H)-pyrazinone intermediates. Palladium-catalyzed cross-couplings and S_NAr reactions were used to introduce substituents chosen on the basis of the calculated physicochem. properties of the target pyrazinones. Representative compounds, e.g., I, demonstrated good solubility, kinase inhibitory activity and antiproliferative activity in human tumor cells, confirming the suitability of this chem. class as a kinase-focused library.

Tetrahedron published new progress about 724710-02-5. 724710-02-5 belongs to pyrazoles-derivatives, auxiliary class Pyrazole,Boronic acid and ester,Pyrazole,Boronic Acids,Boronic acid and ester, name is (1H-Pyrazol-5-yl)boronic acid, and the molecular formula is C3H5BN2O2, Category: pyrazoles-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics

Caldwell, John J. published the artcileDesign and synthesis of 2(1H)-pyrazinones as inhibitors of protein kinases, Category: pyrazoles-derivatives, the publication is Tetrahedron (2012), 68(47), 9713-9728, database is CAplus.

Kinase enzymes play a key role in the development and progression of cancer. Inhibitors of deregulated kinases are effective small mol. anticancer drugs. The 2(1H)-pyrazinone heterocycle is a previously unexploited motif that can fulfil the structural requirements for ATP-competitive inhibition of kinases. Rapid solution-phase syntheses of novel 3,5- and 3,6-disubstituted-2(1H)-pyrazinones were developed through selective, sequential substitution of 2,5-dihalo-3-benzyloxypyrazine and 3,5-dihalo-2(1H)-pyrazinone intermediates. Palladium-catalyzed cross-couplings and S_NAr reactions were used to introduce substituents chosen on the basis of the calculated physicochem. properties of the target pyrazinones. Representative compounds, e.g., I, demonstrated good solubility, kinase inhibitory activity and antiproliferative activity in human tumor cells, confirming the suitability of this chem. class as a kinase-focused library.

Tetrahedron published new progress about 763120-58-7. 763120-58-7 belongs to pyrazoles-derivatives, auxiliary class Pyrazole,Boronic acid and ester,Boronic Acids,Boronic acid and ester, name is 1H-Pyrazole-4-boronic acid, and the molecular formula is C3H5BN2O2, Category: pyrazoles-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics