Heterocyclic Building Blocks-Pyridazine

Demange, Luc; Abdellah, Fatma Nait; Lozach, Olivier; Ferandin, Yoan; Gresh, Nohad; Meijer, Laurent; Galons, Herve published the artcile< Potent inhibitors of CDK5 derived from roscovitine: Synthesis, biological evaluation and molecular modelling>, Related Products of 20744-39-2, the main research area is isopropyl hydroxyalkylamino arylamino purine preparation roscovitine analog CDK5 inhibitor; structure isopropyl hydroxyalkylamino arylamino purine inhibition CDK5 DYRK1A kinase; mol docking energetics isopropyl hydroxyalkylamino arylamino purine binding CDK5; cell death induction CDK5 inhibiting isopropyl hydroxyalkylamino arylamino purine.

9-Isopropyl-2-(hydroxyalkylamino)-6-(arylamino)purines I [R = 2-pyridinyl, 3-pyridinyl, 4-pyridinyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl, 2-pyrazinyl, 4-pyridazinyl; R1 = Cl, (R)-Et(HOCH2)CHNH, (S)-Et(HOCH2)CHNH, (R)-Me2CH(HOCH2)CHNH, (S)-Me2CH(HOCH2)CHNH, (HOCH2)2CH, HOCH2CMe2NH, 5-pyrimidinylamino, 2-pyrazinylamino] were prepared as analogs of the CDK inhibitor roscovitine for potential use as selective inhibitors of cyclin-dependent kinase 5 (CDK5) over CDK2, glycogen synthase kinase-3 (GSK3αβ), and casein kinase 1 (CK1). Regioselective alkylation of 2,6-dichloropurine, regioselective Buchwald-Hartwig amination with arylamines, and reaction with amino alcs. yielded I, with chlorides generated by omission of the reaction with amino alcs., and I (R = R1 = 5-pyrimidinylamino, 2-pyrazinylamino) generated as diamination byproducts from Buchwald-Hartwig amination. I [R = 3-pyridinyl, 4-pyridinyl, 5-pyrimidinyl, 4-pyridazinyl; R1 = (R)-Et(HOCH2)CHNH, (S)-Et(HOCH2)CHNH, (R)-Me2CH(HOCH2)CHNH] inhibited CDK5 with IC50 values ranging from 17 to 50 nM and induced cell death in human neuroblastoma cells with IC50 values ranging from 2 to 9 μM in SH-SY5Y cells. Mol. docking of I [R = 4-pyrimidinyl; R1 = (R)-Et(HOCH2)CHNH] and I [R = 4-pyridazinyl; R1 = (R)-Et(HOCH2)CHNH] into the ATP binding domain of the CDK5 catalytic site highlighted the importance of a hydrogen bond between the arylamino ring nitrogen atoms and residue Lys-89 of CDK5 for enzyme inhibition. The calculated final energy balances for complexation measured for several inhibitors is consistent with the ranking of the IC50 values. I [R = 3-pyridinyl, 5-pyrimidinyl; R1 = (R)-Me2CH(HOCH2)CHNH, (S)-Me2CH(HOCH2)CHNH] inhibited dual specificity, tyrosine phosphorylation regulated kinase 1A (DYRK1A), a kinase involved in Down’s syndrome and Alzheimer’s disease, with IC50 values ranging from 300 to 400 nM.

Bioorganic & Medicinal Chemistry Letters published new progress about Cell death. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Related Products of 20744-39-2.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Sakai, Taki; Matsumoto, Yotaro; Ishikawa, Minoru; Sugita, Kazuyuki; Hashimoto, Yuichi; Wakai, Nobuhiko; Kitao, Akio; Morishita, Era; Toyoshima, Chikashi; Hayashi, Tomoatsu; Akiyama, Tetsu published the artcile< Design, synthesis and structure-activity relationship studies of novel sirtuin 2 (SIRT2) inhibitors with a benzamide skeleton>, Formula: C4H5N3, the main research area is benzamide derivative preparation SAR sirtuin 2 inhibitor; SIRT2; Sirtuin.

Human sirtuin 2 (SIRT2) is an attractive target mol. for development of drugs to treat neurodegenerative diseases and cancer, because SIRT2 inhibitors have a protective effect against neurodegeneration and an anti-proliferative effect on cancer stem cells. We designed and synthesized a series of benzamide derivatives as SIRT2 inhibitor candidates. Among them, compound (I) showed the most potent SIRT2-inhibitory activity (IC50 = 0.60 μM), with more than 150-fold selectivity over SIRT1 and SIRT3 isoforms (IC50 >100 μM).

Bioorganic & Medicinal Chemistry published new progress about Antitumor agents. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Formula: C4H5N3.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Woodring, Jennifer L.; Lu, Shao-Hung; Krasnova, Larissa; Wang, Shih-Chi; Chen, Jhih-Bin; Chou, Chiu-Chun; Huang, Yi-Chou; Cheng, Ting-Jen Rachel; Wu, Ying-Ta; Chen, Yu-Hou; Fang, Jim-Min; Tsai, Ming-Daw; Wong, Chi-Huey published the artcile< Disrupting the Conserved Salt Bridge in the Trimerization of Influenza A Nucleoprotein>, Computed Properties of 20744-39-2, the main research area is antiviral drug influenza infections neuraminidase inhibitors SAR mol docking.

Antiviral drug resistance in influenza infections has been a major threat to public health. To develop a broad-spectrum inhibitor of influenza to combat the problem of drug resistance, we previously identified the highly conserved E339…R416 salt bridge of the nucleoprotein trimer as a target and compound 1 as an inhibitor disrupting the salt bridge with an EC50 = 2.7μM against influenza A (A/WSN/1933). We have further modified this compound via a structure-based approach and performed antiviral activity screening to identify compounds 29 and 30 with EC50 values of 110 and 120 nM, resp., and without measurable host cell cytotoxicity. Compared to the clin. used neuraminidase inhibitors, these two compounds showed better activity profiles against drug-resistant influenza A strains, as well as influenza B, and improved survival of influenza-infected mice.

Journal of Medicinal Chemistry published new progress about Antiviral agents. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Computed Properties of 20744-39-2.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Kwiatkowski, J. S. published the artcile< Electronic structure and spectra of organic molecules. XVI. Amine-imine tautomerism in azines substituted by amino groups>, Application of C4H5N3, the main research area is tautomerism aminoazine electronic structure; azine tautomerism electronic structure; iminoazine electronic transition energy; pyridine tautomerism electronic structure; diazine tautomerism electronic structure.

For both amine and imine tautomers of amine-substituted pyridines and diazines, Pariser-Parr-Pople type calculations (K., 1970) gave singlet-singlet transition energies which agreed with exptl. data. In all cases, the singlet-singlet transitions of the imine forms red shifted relative to the corresponding transitions of the amine forms.

Acta Physica Polonica, A published new progress about Tautomers. 20744-39-2 belongs to class pyridazine, and the molecular formula is C4H5N3, Application of C4H5N3.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

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>, Reference 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, Reference 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>, Recommanded Product: Pyridazin-4-amine, 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, Recommanded Product: Pyridazin-4-amine.

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>, Recommanded Product: Pyridazin-4-amine, 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, Recommanded Product: Pyridazin-4-amine.

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>, Recommanded Product: Pyridazin-4-amine, 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, Recommanded Product: Pyridazin-4-amine.

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>, Formula: C9H8ClN3O2, 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, Formula: C9H8ClN3O2.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem

Itai, Takanobu; Natsume, Sachiko published the artcile< Potential anticancer agents. IX. Nitration of pyridazine 1-oxide>, Related Products of 20744-39-2, 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, Related Products of 20744-39-2.

Referemce:
Pyridazine – Wikipedia,
Pyridazine | C4H4N2 – PubChem