Heterocyclic Building Blocks-Pyridazine

Xiao, Fang; Lin, Jin-Hong; Hao, Fei; Zheng, Xing; Guo, Yu; Xiao, Ji-Chang published the artcile< Visible light mediated C-H trifluoromethylation of (hetero)arenes>, Application In Synthesis of 64067-99-8, the main research area is trifluoromethyl heteroarene preparation; aromatic heterocycle visible light trifluoromethylation.

A protocol for visible light mediated C-H trifluoromethylation of unactivated (hetero)arenes under blue LED irradiation has been developed. The reaction enables the rapid construction of a range of CF3-containing (hetero)arenes in moderate to high yields from the readily accessible trifluoromethylsulfonyl-pyridinium salt (TFSP). This protocol is also suitable for nitrogen-containing aromatic heterocycles, which are potentially useful in medicinal chem.

Organic Chemistry Frontiers published new progress about Heterocyclic aromatic compounds Role: RCT (Reactant), SPN (Synthetic Preparation), RACT (Reactant or Reagent), PREP (Preparation). 64067-99-8 belongs to class pyridazine, and the molecular formula is C9H8ClN3O2, Application In Synthesis of 64067-99-8.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Tsujimoto, Toshio; Nomura, Toshiro; Iifuru, Makiko; Sasaki, Yoshio published the artcile< Studies on carbon-13 magnetic resonance spectroscopy. XIII. Carbon-13 and proton NMR of 4-substituted pyridazine and 2-substituted pyrazine derivatives>, Product Details of C4H5N3, the main research area is NMR carbon pyridazine pyrazine derivative; substituent constant pyridazine pyrazine derivative.

13C NMR chem. shifts of 4-substituted pyridazines and 2-substituted pyrazines, together with 1H chem. shifts of the former compounds were measured. Linear correlations of the 13C and 1H chem. shifts of 4-substituted pyridazines with those of monosubstituted benzenes and monosubstituted pyridines and with substituent constants σπ were found. In addition, similar trends were noted for 2-substituted pyrazines. Chem. shifts of pyridazines and pyrazines can be predicted on the basis of these relationships.

Chemical & Pharmaceutical Bulletin published new progress about NMR (nuclear magnetic resonance). 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Product Details of C4H5N3.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Devine, William; Thomas, Sarah M.; Erath, Jessey; Bachovchin, Kelly A.; Lee, Patricia J.; Leed, Susan E.; Rodriguez, Ana; Sciotti, Richard J.; Mensa-Wilmot, Kojo; Pollastri, Michael P. published the artcile< Antiparasitic Lead Discovery: Toward Optimization of a Chemotype with Activity Against Multiple Protozoan Parasites>, Application of C4H5N3, the main research area is trypanosomicide leishmanicide antimalarial development NEU1045 analog preparation pharmacokinetics; Antiparasitic agents; Chagas disease; Leishmania major; Plasmodium falciparum; Trypanosoma brucei; Trypanosoma cruzi; human African trypanosomiasis; leishmaniasis.

Human African trypanosomiasis (HAT), Chagas disease, and leishmaniasis present a significant burden across the developing world. Existing therapeutics for these protozoal neglected tropical diseases suffer from severe side effects and toxicity. Previously, NEU-1045 was identified as a promising lead with cross-pathogen activity, though it possessed poor physicochem. properties. The authors have designed a library of analogs with improved calculated physicochem. properties built on the quinoline scaffold of 3 incorporating small, polar aminoheterocycles in place of the 4-(3-fluorobenzyloxy)aniline substituent. The authors report the biol. activity of these inhibitors against Trypanosoma brucei (HAT), T. cruzi (Chagas disease), and Leishmania major (cutaneous leishmaniasis), and describe the identification of N-(5-chloropyrimidin-2-yl)-6-(4-(morpholinosulfonyl)phenyl)quinolin-4-amine (13t) as a promising inhibitor of L. major proliferation and 6-(4-(morpholinosulfonyl)phenyl)-N-(pyrimidin-4-yl)quinolin-4-amine (13j), a potent inhibitor of T. brucei proliferation with improved drug-like properties.

ACS Medicinal Chemistry Letters published new progress about Antimalarials. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Application of C4H5N3.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Mason, S. F. published the artcile< The electronic spectra of N-heteroaromatic systems. VI. The π → π transitions of monocyclic amino- and mercaptoazines>, Category: pyridazine, the main research area is .

Ultraviolet absorption spectra are reported for 2-(I), 3-, and 4-aminopyridine (II), 2-(III), 4-(IV), and 5-aminopyrimidine, 4-aminopyridazine, 2-aminopyrazine, and 3-amino-6-methylpyridazone (V), in approx. neutral solution (pH about 7-9.5) and in acid (pH 1), and the 1-methochlorides of I, II, III, and IV, and the 2-methochloride of V, at pH 12-14. Most of the neutral spectra are repeated in EtOH and cyclohexane, and spectra of 1-methyl-2-, and -4-pyridone imine, 1-methyl-2-, and -4-pyrimidone imine and 2,6-dimethyl-3-pyridazone imine are reported in H2O and cyclohexane. Spectra are also reported for 2-, 3-, and 4-methylthiopyridine and for 4-methyl-2-methylthio-, 2-mercapto-4-methyl-, 6-methyl-4-methylthio-, and 4-mercapto-6-methylthiopyrimidine in neutral, acidic, and basic solution The spectra are discussed in relation to a benzyl anion model (loc. cit.) and a substituted benzene charge transfer model (Murrell, C.A. 53, 6749b). The latter model is more consistent with the exptl. data.

Journal of the Chemical Society published new progress about Azines. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Category: pyridazine.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Kosary, Judit; Kasztreiner, Endre; Rabloczky, Gyorgy; Kurthy, Maria published the artcile< Synthesis and cardiotonic activity of 2,4-diamino-1.3,5-triazines>, Safety of Ethyl 6-chloroimidazo[1,2-b]pyridazine-2-carboxylate, the main research area is aminotriazine heteroaryl preparation cardiotonic; triazine diaminoheteroaryl preparation cardiotonic.

Thirty-two diaminotriazine derivatives, e.g., I (R = NH2, NHBu, NMe2, morpholino, 4-methylpiperazino; R1 = indol-3-yl, imidazo[1,2-a]pyridin-2-yl, imidazo[1,2-b]pyridazin-2-yl, imidazo[1,2-a]pyrazin-2-yl, etc.] were prepared and tested for cardiotonic activity in cats. There was no correlation between the cardiotonic activity of these compounds and their inhibitory effect on cardiac phosphodiesterase.

European Journal of Medicinal Chemistry published new progress about Cardiotonics. 64067-99-8 belongs to class pyridazine, and the molecular formula is C9H8ClN3O2, Safety of Ethyl 6-chloroimidazo[1,2-b]pyridazine-2-carboxylate.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Itai, Takanobu; Natsume, Sachiko published the artcile< Potential anticancer agents. IX. Nitration of pyridazine 1-oxide>, Category: pyridazine, the main research area is .

Preceding abstract To 5 g. pyridazine 1-oxide (I) in 40 cc. cold CHCl3 was added 6 cc. BzCl, followed portionwise by 9.7 g. finely powd. AgNO3 at below – 10° with stirring, the mixture stirred 4 hrs. at below – 10°, kept 4 days at room temperature, the precipitate (II) (mixture of AgCl and a yellow solid) filtered off, washed twice with cold CHCl3 [the combined filtrate and washings (III) were kept], extracted with hot CHCl3, and the extract concentrated to dryness to give 2.15 g. 3-NO2 derivative (IV) of I, m. 166° (MeOH), ν (KBr) 1543, 1523, 1337, 1324 cm.-1, (95% EtOH) 232, 281, and 350 mμ (log ε 4.02, 3.99, and 3.73); the MeOH mother liquor evaporated, the residue chromatographed on SiO2, and the column eluted gave the following fractions: (1) with 9:1 C6H6CHCl3, 50 mg. BzOH; (2) with same solvent mixture, 22 mg. 5-NO2 derivative (V) of I, m. 142-3° (MeOH); (3) with same solvent mixture, 45 mg. IV, m. 167-9° (MeOH); (4) with CHCl3, 100 mg. sirupy mixture; and (5) with CHCl3, 270 mg. unchanged I (perchlorate m. 184°). The residue remaining after extracting II with hot CHCl3 extracted with hot MeOH gave 0.06 g. IV; III evaporated, the residue treated with 30 cc. H2O and 60 cc. Et2O, and the precipitate filtered off [the filtrate (VI) was kept] gave 0.12 g. IV, m. 169° (MeOH); VI extracted with Et2O and the extract dried and evaporated gave 5.9 g. BzOH; the remaining aqueous layer evaporated in vacuo, the residue extracted repeatedly with CHCl3, the combined extracts dried, evaporated, and the residue chromatographed on SiO2 as above gave 40 mg. V, m. 142-3°, 45 mg. IV, m. 169°, and 1.12 g. unchanged I. I (5 g.) in 50 cc. cold CHCl3 treated with 4.1 cc. AcCl followed portionwise by 9.7 g. finely powd. AgNO3 at below -10° with stirring, the mixture stirred 1.5 hrs. at below – 10°, kept 3 days at room temperature, and worked up as above gave 1.26 g. IV, 57 mg. V, and 1.72 g. unchanged I. V (0.042 g.) in 15 cc. 50% MeOH containing 1 cc. concentrated HCl hydrogenated over 20% Pd-C, when 4 equivalents H were absorbed the solution filtered, the filtrate evaporated, the residue dissolved in a little MeOH, and the solution treated with MeOH-Na picrate (VIa) gave 4-aminopyridazine (VII) picrate, m. 226-8° (decomposition) (MeOH), converted by passage in MeOH through Amberlite IRA-410 (OH form) into VII, m. 127-9°. IV (145 mg.) suspended in 30 cc. MeOH and 30 cc. 4% aqueous HCl hydrogenated over 20% Pd-C (prepared from 4.2 cc. 1% aqueous PdCl2 and 0.1 g. C) (the reduction was interrupted after rapid absorption of 4 equivalents H), the product (100 mg.) isolated as usual, and treated with 1 equivalent VIa gave 100 mg. 3-aminopyridazine (VIII) picrate (IX), m. 248-9° (EtOH), converted as above into VIII, m. 170°. IV (1.08 g.) and 20% Pd-C (prepared from 0.2 g. C and 8.4 cc. 1% aqueous PdCl2) in 100 cc. MeOH shaken in a stream of H until 2 equivalents H were absorbed (H was absorbed rapidly), the mixture warmed, the catalyst filtered off hot, washed with hot MeOH, and the combined filtrate and washings evaporated gave 0.74 g. 3-hydroxyaminopyridazine 1-oxide (X), m. 184° (decomposition) (EtOH);λ (95% EtOH) 229,262, and 341 mμ (log ε 4.17, 4.14, and 3.63); ν (KBr) 3160 cm.-1 IV (1.06 g.) and 20% Pd-C (prepared from 0.2 g. C and 8.4 cc. 1% aqueous PdCl2) in 200 cc. MeOH hydrogenated as above until uptake of 3 equivalents H, the mixture worked up as above, and the residue recrystallized from MeOH gave 0.2 g. X, m. 182° (decomposition). The mother liquor evaporated, the residue dissolved in MeOH, the solution treated with MeOH-picric acid, and the precipitate filtered off gave 0.25 g. IX, m. 248-9° (MeOH); the filtrate kept overnight with Amberlite IRA-410 (OH form), the resin filtered off, and the filtrate evaporated gave 0.27 g. VIII 1-oxide (XI), m. 139-41° (EtOAc); λ (95% EtOH) 217, 246-8, and 338-40 mμ (log ε 4.23, 4.13, and 3.74); ν (KBr) 3340, 3300, 3210, 1632 cm.-1 X (0.2 g.) and 0.12 g. 20% Pd-C in 50 cc. MeOH shaken in a stream of H until 1 equivalent H was absorbed and treated as above gave 60 mg. IX, m. 245-9°, and 75 mg. XI, m. 139-41°. IV (0.2 g.) suspended in 70 cc. anhydrous MeOH treated with NaOMe solution (prepared from 40 mg. Na and 7 cc. MeOH), the mixture kept 1.5 hrs. at 30° (IV dissolved slowly), and the precipitate filtered off and washed with C6H6 gave 30 mg. unchanged IV, m. 168-9°; the combined filtrate and washings evaporated in vacuo, the residue treated with a little H2O, and the product isolated with CHCl3 gave 137 mg. 3-OMe derivative (XII) of I, m. 79-80° (C6H6). IV (0.4 g.) in 50 cc. hot MeOH mixed with 10 cc. MeONa solution (prepared from 80 mg. Na) and the solution refluxed 1 hr. and treated as above gave 0.26 g. XII. IV (0.59 g.) suspended in 15 cc. AcCl refluxed until solution occurred (9 hrs.), the AcCl removed in vacuo, and the residue recrystallized from (iso-Pr)2O gave 0.36 g. 3-Cl derivative (XIII) of I, m. 93°, λ (95% EtOH) 266 mμ (log ε 4.00), ν (KBr) 1340 cm.-1 ; the mother liquor evaporated and the residue chromatographed on Al2O3 with CHCl3 gave 80 mg. XIII. IV (0.1 g.) suspended in 1 cc. AcCl kept 3 hrs. at 35°, the mixture evaporated in vacuo, and the residue extracted repeatedly with (iso-Pr)2O gave (as insoluble product) 90 mg. unchanged IV, m. 167-9°; the combined extracts evaporated and the residue chromatographed on Al2O3 with CHCl3 gave 2 mg. XIII. IV (0.15 g.) added to 0.4 g. Na dissolved in 0.7 g. PhOH by warming, the mixture heated 1 hr. at 100°, the PhOH removed in vacuo, the residue treated with H2O, the product isolated with CHCl3, the residue dissolved in CHCl3, the solution passed through Al2O3, and the eluate evaporated gave 100 mg. 3-OPh derivative of I, m. 115-16° (C6H6). HONH2.HCl (0.27 g.) in MeOH (saturated solution) treated with 0.27 g. K2CO3 in a little H2O, the precipitate filtered off, the filtrate treated with 80 mg. XIII in 3 cc. MeOH, refluxed 5.5 hrs., evaporated to dryness, the residue treated with a little H2O, the mixture extracted with CHCl3, and the extract evaporated gave 22 mg. unchanged XIII, m. 90-2° (iso-Pr)2O; the product insoluble in CHCl3 and H2O filtered off and recrystallized from EtOH gave 6 mg. X, m. 182-3° (decomposition). XIII (0.2 g.), 5 cc. EtOH, and 3 cc. 28% aqueous NH3 heated 4 hrs. at 120° in a sealed tube, the mixture treated with C, the solution evaporated in vacuo, the residue extracted repeatedly with hot EtOAc, and the combined extracts evaporated gave 0.05 g. XI, m. 140-1° (EtOAc). XIII (0.17 g.) in 10 cc. MeOH treated with NaOMe solution (prepared from 30 mg. Na and 5 cc. MeOH), the mixture kept overnight at room temperature, evaporated in vacuo, the residue treated with a little H2O, the mixture extracted with CHCl3, the extract dried, evaporated, and the residue chromatographed on Al2O3 with C6H6 gave 130 mg. XII, m. 78-80°. XIII (0.05 g.) and 0.04 cc. 80% N2H4.H2O in 1 cc. 95% EtOH refluxed 1 hr., cooled, evaporated in vacuo, the residue dissolved in 1 cc. AcOH, the solution treated with 0.03 g. NaNO2 in H2O with cooling, and the precipitate collected gave 30 mg. 3-azido derivative of I, m. 155-6° (99% MeOH), ν (KBr) 2180, 2150, and 1250 cm.-1 IV shown no activity of Ehrlich ascite carcinoma in vivo, it showed strong activity against Staphylococcus aureus, Escherichia coli, Shigella flexneri, and Candida albicans in vitro.

Chemical & Pharmaceutical Bulletin published new progress about IR spectra. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Category: pyridazine.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Nakagome, Takenari published the artcile< Syntheses of pyridazine derivatives. II. 3-Methoxy-6-pyridazinol 1-oxide>, Recommanded Product: Pyridazin-4-amine, the main research area is HETEROCYCLIC COMPOUNDS/chemistry.

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), b0.15 120-5°, 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°.

Yakugaku Zasshi published new progress about 20744-39-2. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Recommanded Product: Pyridazin-4-amine.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Haider, N.; Holzer, W. published the artcile< Product class 8: pyridazines>, Product Details of C4H5N3, the main research area is review pyridazine preparation cyclization; ring transformation pyridazine preparation review; aromatization pyridazine preparation review.

A review. Methods of preparing pyridazines are reviewed including cyclization, ring transformation, aromatization, and substituent modification.

Science of Synthesis published new progress about Aromatization. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Product Details of C4H5N3.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Itai, Takanobu; Kamiya, Shozo published the artcile< Potential anticancer agents. XI. Synthesis of 4- and 5-azidopyridazine 1-oxide>, Product Details of C4H5N3, the main research area is .

The reaction of NaOMe with 3,4,5-trichloropyridazine (I) was studied. 4-Azidopyridazine 1-oxide (II) and 5-azidopyridazine 1-oxide (III) were synthesized from the corresponding hydrazino compounds 4-hydrazinopyridazine 1-oxide (IV) and 5-hydrazinopyridazine 1-oxide (V) with HNO2; II was also derived from 4-chloropyridazine 1-oxide (VI). I (4.88 g.) kept 1 hr. at 0-5° with 0.61 g. Na in 50 ml. MeOH, then 3 hrs. at room temperature, refluxed 1 hr., the filtrate evaporated, and the product crystallized gave 1.6 g. 5-methoxy-3,4-dichloropyridazine (VII), m. 101-2°. VII (1 g.) in 20 ml. MeOH treated with H and Pd-C gave quant. 4-methoxypyridazine, m. 143-4°. VII (1.4 g.) refluxed 3 hrs. with 0.18 g. Na in 20 ml. MeOH gave 0.57 g. 4-chloro-3,5-dimethoxypyridazine (VIII), m. 161-2°. The mother liquors afforded 0.36 g. 3-chloro-4,5-dimethoxypyridazine (IX), m. 91-2°. VIII was dehalogenated by catalytic hydrogenation in the presence of concentrated NH4OH to give 74% 3,5-dimethoxypyridazine, m. 73-5°. Similarly, IX gave 4,5-dimethoxypyridazine, m. 98-100°; picrate m. 165°. I (5.22 g.) similarly treated with 2 equimolar amounts of MeONa gave 25% VIII and 41% IX. VI (1.042 g.) heated 2 hrs. with 0.19 g. Na in 40 ml. MeOH gave 0.97 g. 4-methoxypyridazine 1-oxide (X), m. 124-5°. X (0.97 g.), 5 ml. 80% N2H4.H2O, and 5 ml. alc. refluxed 3 hrs. gave 0.42 g. IV, m. 192-3° (decomposition); benzylidene derivative m. 252° (decomposition); isopropylidene derivative m. 218°; cyclohexylidene derivative m. 196-9°. IV (0.1 g.) in 5 ml. 5% HCl treated dropwise with 55 mg. NaNO2 in 2 ml. H2O, kept 20 min., and basified gave 52 mg. II, m. 123° (decomposition). VI (0.6 g.), 0.6 g. NaN3, 2 ml. H2O, and 8 ml. alc. heated 5 hrs. in a sealed tube gave 51% II. The aqueous layer afforded 4% 4-aminopyridazine 1-oxide. II (0.25 g.) in 10 ml. CHCl3, refluxed 2 hrs. with 0.7 g. PCl3, evaporated, the residue left with 5 ml. ice-H2O, basified, and extracted with CHCl3 gave 0.16 g. 4-azidopyridazine (XI), m. 62-4°. XI (30 mg.) in 5 ml. MeOH shaken 5 min. with Pd-C and H gave 4-aminopyridazine, m. 129-30°. IV (0.2 g.), 0.24 g. acetylacetone, and 30 ml. alc. refluxed 3 hrs. gave 0.23 g. 4-(3,5-dimethyl-1-pyrazolyl)pyridazine 1-oxide (XIa), m. 155-6°. 5-Methoxypyridazine 1-oxide (0.55 g.), 5 ml. alc., and 2.5 ml. 80% N2H4.H2O refluxed 1 hr. gave 0.3 g. V, m. 188° (decomposition); benzylidene derivative m. 280° (decomposition). V (0.2 g.) in 5 ml. 5% HCl treated 20 min. with 0.12 g. NaNO2 in H2O gave 0.16 g. III, m. 100-2° (decomposition). 3-Azidopyridine (3.1 g.), 40 ml. AcOH, and 7 ml. 30% H2O2 heated 3 hrs. at 75°, then 3 hrs. with 4 ml. more 30% H2O2, and the product separated gave 2.25 g. 3-azidopyridine 1-oxide (XII) m. 99-103°. XII refluxed 2 hrs. with Na in MeOH gave 90% starting material. II (0.1 g.) refluxed 1 hr. with 17 mg. Na in 10 ml. MeOH, evaporated, the residue extracted with hot CHCl3, evaporated, and crystallized gave 74% X. II similarly treated with PhCH2ONa gave 71% 4-benzyloxypyridazine 1-oxide, m. 140-1°. III (0.12 g.) heated 1 hr. with Na in anhydrous PhCH2OH gave 51% 5-benzyloxypyridazine 1-oxide, m. 100-2°. Similar treatment of XIa with MeONa gave 63% 5-methoxypyridazine 1-oxide, m. 106-9°.

Chemical & Pharmaceutical Bulletin published new progress about Neoplasm. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Product Details of C4H5N3.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Harcken, Christian; Riether, Doris; Kuzmich, Daniel; Liu, Pingrong; Betageri, Raj; Ralph, Mark; Emmanuel, Michel; Reeves, Jonathan T.; Berry, Angela; Souza, Donald; Nelson, Richard M.; Kukulka, Alison; Fadra, Tazmeen N.; Zuvela-Jelaska, Ljiljana; Dinallo, Roger; Bentzien, Jorg; Nabozny, Gerald H.; Thomson, David S. published the artcile< Identification of Highly Efficacious Glucocorticoid Receptor Agonists with a Potential for Reduced Clinical Bone Side Effects>, Application In Synthesis of 20744-39-2, the main research area is nonsteroidal glucocorticoid receptor agonist antiinflammatory reduced bone side effect.

Synthesis and structure-activity relationship (SAR) of a series of nonsteroidal glucocorticoid receptor (GR) agonists are described. These compounds contain “”diazaindole”” moieties and display different transcriptional regulatory profiles in vitro and are considered “”dissociated”” between gene transrepression and transactivation. The lead optimization effort described in this article focused in particular on limiting the transactivation of genes which result in bone side effects and these were assessed in vitro in MG-63 osteosarcoma cells, leading to the identification of the R enantiomers of I and II. These compounds maintained anti-inflammatory activity in vivo in collagen induced arthritis studies in mouse but had reduced effects on bone relevant parameters compared to the widely used synthetic glucocorticoid prednisolone in vivo. To our knowledge, we are the first to report on selective glucocorticoid ligands with reduced bone loss in a preclin. in vivo model.

Journal of Medicinal Chemistry published new progress about Anti-inflammatory agents. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Application In Synthesis of 20744-39-2.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem