Heterocyclic Building Blocks-Pyridazine

Syntheses of pyridazine derivatives. II. 3-Methoxy-6-pyridazinol 1-oxide was written by Nakagome, Takenari. And the article was included in Yakugaku Zasshi in 1962.COA of Formula: C5H6N2O This article mentions the following:

3-Chloro-6-methoxypyridazine (I) (7.3 g.) in 50 mL. AcOH treated with 24 mL. 30% H₂O₂, kept 5 h. at 70°, the solution concentrated in vacuo, the residue made alk. with Na₂CO₃ and the product extracted with CHCl₃ gave 1.4 g. 3-methoxy-6-chloropyridazine 1-oxide (II), m. 157-8° (C₆H₆). The mother liquor from washing II with 2N NaOH gave 0.4 g. 3-methoxy-6(1H)-pyridazinone (III), plates, m. 162-3° (AcOEt). A solution of 18 g. BzO₂H in 337 mL. CHCI₃ treated with 14.5 g. I, kept 3 days at room temperature and the product treated as above gave 14.3 g. II, m. 157-8°. I (3 g.), 20 mL. AcOH, and 3.4 g. AcOK in a sealed tube heated 1.5 h. at 140-50° and the AcOH removed gave 3.6 g. III, m. 162-3°. III (4 g.) and 30 mL. POCl₃ heated 30 min. at 100° the product poured into ice-H₂O and extracted with Et₂O gave 1.5 g. 3,6-dichloropyridazine (IV), m. 68-9°. Catalytic reduction of 0.5 g. II in 3 mL. 28% NH₄OH and 30 mL. MeOH with 0.05 g. 10% Pd-C absorbed 77 mL. H and gave 0.35 g. 3-methoxypyridazine 1-oxide (V), m. 79-80°. Catalytic reduction of 0.5 g. II in 3 mL. 28% NH₄OH and 30 mL. MeOH with Pd-C (from 10 mL. 1% PdCl₂ and 0.5 g. C) absorbed 160 mL. H in 15 min. and gave 0.5 g. 3-methoxypyridazine; picrate m. 111°. II (3.2 g.), 12 mL. AcOH, and 1.64 g. AcONa in a sealed tube heated 1 h. at 150-60° and the product concentrated gave 1.64 g. 1-hydroxy-3-methoxy-5(1H)-pyridazinone (VI), m. 178-9°. A solution of 29.5 g. 3,6-dimethoxypyridazine I-oxide in 400 mL. 2N HCl heated 20 min. at 80-90° and the solution concentrated gave 25.3 g. VI, m. 178-9°. VI (2.8 g.), 2.54 g. BzCl, 0.46 g. Na and 30 mL. MeOH in a sealed tube heated 2 h. at 100° the solution concentrated and the residue extracted with CHCl₃ gave 3.1 g. 1-benzoyloxy-3-methoxy-6(1H)pyridazinone (VII), m. 86.5-87°. VI (2 g.), 2.5 g. MeI, Ag₂O (from 3 g. AgNO₃), and 20 mL. MeOH in a sealed tube heated 2 h. at 100° and the solution concentrated gave 100% 1,3-dimethoxy-6(1H)-pyridazinone, m. 66-7°. A solution of 250 mL. dry C₆H₆, 20.6 g. PhCH₂OH, and 4.4 g. Na, refluxed 1 h., after disappearance of Na, with 20 g. 3-chloropyridazine, and the product distilled gave 18 g. 3-benzyloxypyridazine (VIII), b_0.15 120-5°, m. 49-50°. VIII (6 g) and 84.5 mL. CHCl₃ containing 4.46 g. BzO₂H kept 2 days at room temperature gave 100% VIII I-oxide (VIIIa), m. 118-18.5°. Catalytic reduction of 0.5 g. VIIIa in 30 mL. MeOH with 0.05 g. 10% Pd-C absorbed 64 mL. H in 5 min.and gave 3-pyridazinol 1-oxide, m. 201-2° (decomposition). Catalytic reduction of 0.5 g. VIIIa in 30 mL. MeOH with 0.2 g. 10% Pd-C absorbed 128 mL. H in 15 min. and gave 0.25 g. 3(2H)-pyridazinone-H₂O, m. 74°. IV (21 g.) and 240 mL. CHCl₃ containing 18.7 g. BzO₂H kept 2 days at room temperature and the product concentrated gave 10.4 g. IV 1-oxide, m. 110-12°. IV 1-oxide (1 g.) and 0.33 g. 22.6% MeONa-MeOH heated several min. on a water bath, the solution acidified with AcOH and the product extracted with CHCl₃ gave 0.6 g. II, m. 155-7°. In the experiment, the researchers used many compounds, for example, 3-Methoxypyridazine (cas: 19064-65-4COA of Formula: C5H6N2O).

3-Methoxypyridazine (cas: 19064-65-4) belongs to pyridazine derivatives. Pyridazine and phthalazine have quite different spectroscopic properties compared with their isomers, pyrazine and quinoxaline. Pyridazine compounds have attracted interest in various fields like medicinal, industrial, and agricultural research as they are used for numerous biological activities and other applications.COA of Formula: C5H6N2O

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

The tautomerism of N-heteroaromatic hydroxy compounds. III. Ionization constants was written by Mason, S. F.. And the article was included in Journal of the Chemical Society in 1958.Category: pyridazine This article mentions the following:

Acidic and basic ionization constants are reported for a number of N-heteroaromatic hydroxy compounds and their O- and N-Me derivatives From the measured and from published values, tautomeric equilibrium constants (K_t = [NH form]/[OH form]) were estimated for the monoaza compounds, and for the diaza compounds with not more than one N atom conjugated with the OH group. For the diazacompds. with a ring-N atom placed both ortho and para to the OH group, the equilibrium constant (K_op = [ο-quinonoid NH form]/[p-quinonoid NH form]) was similarly estimated Such constants agree, to within an order of magnitude, with those determined spectrophotometrically. The ionization and tautomeric constants vary with the π-electron energies of the species in equilibrium Absorption spectra were measured with a Hilger Uvispek H700/305 Quartz Spectrophotometer, and aqueous solutions with pH values 2 units less than pK₁ value of the 63 compounds examined Ionization constants were determined by potentiometric titration at 20° under N, a Cambridge pH meter being used with glass and calomel electrodes. The ionization constants of the N-heteroaromatic hydroxy compounds were measured at 0.004M and those of the O- and N-Me derivatives at 0.01M. In the experiment, the researchers used many compounds, for example, 3-Methoxypyridazine (cas: 19064-65-4Category: pyridazine).

3-Methoxypyridazine (cas: 19064-65-4) belongs to pyridazine derivatives. Pyridazines are rare in nature, possibly reflecting the scarcity of naturally occurring hydrazines, common building blocks for the synthesis of these heterocycles. Pyridazine is bioavailable (especially in the CNS) and can reduce toxicity. Pyridazine is a component of several drug molecules, and the pyridazine pharmacophore has contributed to a variety of pharmacologically active compounds.Category: pyridazine

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Long-term degradation effect on the molecular composition of black carbon in Brazilian Cerrado soils was written by Justi, Marina;Schellekens, Judith;de Camargo, Plinio Barbosa;Vidal-Torrado, Pablo. And the article was included in Organic Geochemistry in 2017.SDS of cas: 19064-65-4 This article mentions the following:

The effect of long term degradation on soil black carbon (BC) is important for correctly interpreting the role of BC in the global carbon cycle and in biochar studies. To address this, we studied three soil profiles (0-2 m depth, > 9000 yr) in undisturbed Brazilian Cerrado vegetation naturally affected by wildfires. The mol. composition of several soil organic matter (OM) pools was studied using anal. pyrolysis. Other analyses included general chem. and phys. characteristics and micromorphol. The soil OM fractions included the free light fraction (FLF; particulate OM), the occluded light fraction (OLF; particulate OM within aggregates), the 0.1 M NaOH extractable OM (EXT; comparable with the combined humic acid and fulvic acid fractions) and the remaining residue (RES; treated with HF/HCl; comparable with the humin fraction). Although each fraction represents a continuum of material, they were assigned a different degradation level. The light fractions represent relatively intact BC (i.e. charcoal) of which the OLF is more degraded than the FLF, the EXT contains more decomposed material and the RES represents residual OM that is difficult to decompose The largest contribution to the total soil OM was from RES and EXT, together accounting for > 80% of the total soil C. The relative contribution from BC-associated pyrolysis products was generally large for all fractions (between 5% and 57%) and showed an increase with depth in the OLF and RES. Based on factor anal. exclusively applied to BC-associated pyrolysis products from all four OM fractions, two BC degradation indexes were extracted: Index 1, reflecting depolymerization and relative enrichment of N, and Index 2, reflecting a relative increase in condensed structures. Both indexes gradually increased with depth for all fractions, except FLF. Based on these indexes, we selected some simple ratios that showed good correlation with them (r² > 0.7). For Index 1, reflecting depolymerization, adequate ratios for all fractions included benzene/indene and benzene/C₁ naphthalenes. For Index 2, reflecting the relative accumulation of condensed BC, adequate ratios for all fractions included biphenyl/C₂-benzene, fluorene/C₂-benzene and 4-ring PAHs/C₂-benzene. In the experiment, the researchers used many compounds, for example, 3-Methoxypyridazine (cas: 19064-65-4SDS of cas: 19064-65-4).

3-Methoxypyridazine (cas: 19064-65-4) belongs to pyridazine derivatives. Pyridazine-based compounds continued to be a great source of biologically active compounds as evidenced by the number of publications which emerged in 2021. Pyridazine compounds have attracted interest in various fields like medicinal, industrial, and agricultural research as they are used for numerous biological activities and other applications.SDS of cas: 19064-65-4

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Azine Activation via Silylium Catalysis was written by Obradors, Carla;List, Benjamin. And the article was included in Journal of the American Chemical Society in 2021.Reference of 19064-65-4 This article mentions the following:

A direct, catalytic and selective functionalization of azines via silylium activation was described. The catalyst design enabled mild conditions and a remarkable functional group tolerance in a one-pot setup. In the experiment, the researchers used many compounds, for example, 3-Methoxypyridazine (cas: 19064-65-4Reference of 19064-65-4).

3-Methoxypyridazine (cas: 19064-65-4) belongs to pyridazine derivatives. Pyridazines is a six-membered nitrogen-containing significant heterocycle. It has received considerable interest because of its useful applications as natural products, pharmaceuticals, and various bioactive molecules. Pyridazine is bioavailable (especially in the CNS) and can reduce toxicity. Pyridazine is a component of several drug molecules, and the pyridazine pharmacophore has contributed to a variety of pharmacologically active compounds.Reference of 19064-65-4

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

A facile preparation of α-amino-β-methoxydiazines through the lithianation followed by amination was written by Lee, Jung Il;Cho, Sung Hye. And the article was included in Bulletin of the Korean Chemical Society in 1996.Related Products of 19064-65-4 This article mentions the following:

The regioselective lithiation and amination of 4,6-dimethoxypyrimidine gave 4,6-dimethoxy-5-pyrimidinamine in 87% yield. The lithiation of 3-methoxy-4-pyridazine gave 3-methoxy-4-pyridazinamine in 43% yield. In the experiment, the researchers used many compounds, for example, 3-Methoxypyridazine (cas: 19064-65-4Related Products of 19064-65-4).

3-Methoxypyridazine (cas: 19064-65-4) belongs to pyridazine derivatives. The pyridazine derivatives are mostly present in biologically active compounds and are also present with different pharmacophores. Pyridazine compounds have attracted interest in various fields like medicinal, industrial, and agricultural research as they are used for numerous biological activities and other applications.Related Products of 19064-65-4

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Synthesis and In Vitro Evaluation of Imidazo[1,2-b]pyridazines as Ligands for β-Amyloid Plaques was written by Zeng, Fanxing;Alagille, David;Tamagnan, Gilles D.;Ciliax, Brian J.;Levey, Allan I.;Goodman, Mark M.. And the article was included in ACS Medicinal Chemistry Letters in 2010.COA of Formula: C4H2F2N2 This article mentions the following:

A series of imidazo[1,2-b]pyridazine derivatives were synthesized and evaluated for binding to amyloid plaques in vitro using synthetic aggregates of Aβ_1-40. Binding affinities of these compounds were found to range from 11.0 to >1000 nM, depending on the various substitution patterns in the 6-position and 2-position. 2-(4′-Dimethylaminophenyl)-6-(methylthio)imidazo[1,2-b]pyridazine (4) showed high binding affinity (K_i = 11.0 nM) and might be useful for the development of novel positron emission tomog. radiotracers for imaging Aβ plaques. In the experiment, the researchers used many compounds, for example, 3,6-Difluoropyridazine (cas: 33097-39-1COA of Formula: C4H2F2N2).

3,6-Difluoropyridazine (cas: 33097-39-1) belongs to pyridazine derivatives. Pyridazine-based compounds continued to be a great source of biologically active compounds as evidenced by the number of publications which emerged in 2021. In the past decade, X-ray data were reported with regard to the characterization and structural elucidation of a number of pyridazine-metal complexes, including pyridazine ligands with zinc, nickel, copper, cadmium and ruthenium.COA of Formula: C4H2F2N2

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Photolysis of pyridazin-3-one 1-imides: ring contraction into 3-pyrrolin-2-one derivatives was written by Kurita, Jyoji;Takayama, Kazuko;Tsuchiya, Takashi. And the article was included in Chemical & Pharmaceutical Bulletin in 1985.Computed Properties of C5H6N2O This article mentions the following:

Irradiation of pyridazin-3-one 1-ethoxycarbonylimide [I (R = H)] resulted in ring contraction to give the azamaleimide (II), whereas the 6-Me derivative [I (R = Me)], upon irradiation, afforded the 3-pyrrolin-2-one (III). On the other hand, the photolysis of 2-methylpyridazin-3-one 1-imides [IV (R’ = H, Me)] gave both azamaleimides (V; same R’) and 3-pyrrolin-2-ones (VI; same R’). The mechanism of this photoinduced ring contraction reaction is discussed. In the experiment, the researchers used many compounds, for example, 3-Methoxypyridazine (cas: 19064-65-4Computed Properties of C5H6N2O).

3-Methoxypyridazine (cas: 19064-65-4) belongs to pyridazine derivatives. The pyridazine derivatives are mostly present in biologically active compounds and are also present with different pharmacophores. Specifically, the pyridazine moiety is an important structural feature of various pharmacologically important compounds with activities like antimicrobial, analgesic, anti-inflammatory, antiplatelet, anticancer, antisecretory, antiulcer, antidepressant, cardiotonic, vasodilator, antiarrhythmic, and hypocholesterolaemic.Computed Properties of C5H6N2O

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Proton NMR studies of protonation in pyridazin-3(2H)-one and 6-hydroxypyridazin-3(2H)-one was written by Barlin, Gordon B.;Fenn, M. David. And the article was included in Australian Journal of Chemistry in 1979.Quality Control of 3-Methoxypyridazine This article mentions the following:

A ¹H NMR study of protonation in pyridazin-3-ol and pyridazine-3,6-diol revealed that the processes are not simple and suggests that a mobile tautomeric equilibrium may be involved. In the experiment, the researchers used many compounds, for example, 3-Methoxypyridazine (cas: 19064-65-4Quality Control of 3-Methoxypyridazine).

3-Methoxypyridazine (cas: 19064-65-4) belongs to pyridazine derivatives. The pyridazine derivatives are mostly present in biologically active compounds and are also present with different pharmacophores. Pyridazine is bioavailable (especially in the CNS) and can reduce toxicity. Pyridazine is a component of several drug molecules, and the pyridazine pharmacophore has contributed to a variety of pharmacologically active compounds.Quality Control of 3-Methoxypyridazine

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Studies on pyridazine derivatives. IX. Note on the ethoxycarbonylation of pyridazinylhydrazones was written by Matyus, P.;Szilagyi, G.;Kasztreiner, E.;Soti, M.;Sohar, P.. And the article was included in Acta Chimica Academiae Scientiarum Hungaricae in 1982.Application of 33050-32-7 This article mentions the following:

Triazolopyridazine derivative I and pyridazine derivative II were prepared, under different conditions, from the pyridazinylhydrazone III and EtO₂COCO₂Et. The reaction of III with EtO₂COCO₂Et at -10° gave I. A mixture of III and EtO₂COCO₂Et in CH₂Cl₂ was refluxed to give II. In the experiment, the researchers used many compounds, for example, 6-Chloro-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one (cas: 33050-32-7Application of 33050-32-7).

6-Chloro-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one (cas: 33050-32-7) belongs to pyridazine derivatives. The pyridazine derivatives are mostly present in biologically active compounds and are also present with different pharmacophores. Pyridazine can act as a hydrogen bond acceptor to improve the physicochemical properties of drug molecules by increasing their water solubility, and has a high affinity for complexing with targets due to its dipole moment.Application of 33050-32-7

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Synthesis of 6H-1,2,4-triazino-1,2,4-triazolopyridazines. Studies in the field of pyridazine compounds. 22 was written by Kosary, Judit;Jerkovich, Gyula;Polos, Katalin;Kasztreiner, Endre. And the article was included in Magyar Kemiai Folyoirat in 1986.HPLC of Formula: 33050-32-7 This article mentions the following:

The novel ring system 6H-1,2,4-triazino[4,3-b]-1,2,4-triazolo[3,4-f]pyridazine I (R = H, Ph) was prepared either by ring closure of triazolopyridazinylhydrazine derivatives II in polyphosphoric acid or of a hydrazine derived from pyridazino-1,2,4-triazine under the action of tri-Et orthoformate. The first representative of another new ring system 6H-1,2,4-triazino[4,3-b]-1,2,4-triazolo[3,4-f]pyridazine III was prepared by heating triazolopyridazinylhydrazone derivative IV in polyphosphoric acid. I (R = H) and III showed a pos. inotropic effect. In the experiment, the researchers used many compounds, for example, 6-Chloro-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one (cas: 33050-32-7HPLC of Formula: 33050-32-7).

6-Chloro-[1,2,4]triazolo[4,3-b]pyridazin-3(2H)-one (cas: 33050-32-7) belongs to pyridazine derivatives. Pyridazine-based compounds continued to be a great source of biologically active compounds as evidenced by the number of publications which emerged in 2021. The unsubstituted pyridazines are more resistant to eletrophilic substitution due to the nature of withdrawal of electron density from the ring by two heteroatoms, while the related electron deficiency of the ring makes pyridazine more easily attacked by nucleophiles.HPLC of Formula: 33050-32-7

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem