ChemInform Abstract: PYRIDAZINONES. IV. SYNTHESIS, ANTISECRETORY AND ANTIULCER ACTIVITIES OF UREA DERIVATIVES

Abstract

Die Darstellung der Pyridazinonderivate (VIII) und (X) wird beschrieben.

Synthesis, Biological Evaluation, and Pharmacophore Generation of New Pyridazinone Derivatives with Affinity toward α1- and α2-Adrenoceptors

“…This compound was prepared starting from 5 (3.08 g, 10 mmol) with 1,2-dibromoethane (5.63 g, 30 mmol) in benzene (50 mL). Potassium hydroxide pellets (5.61 g, 10 mmol) and tetrabutylammonium bromide (3.2 g, 10 mmol) were then added to the mixture, using the method reported by Yamada . The residue was purified by chromatography on a silica gel column eluting with an EtOH/CH 2 Cl 2 mixture (6:94) to give a 40% yield of a yellow solid: mp 130−135 °C; 1 H NMR (CDCl 3 ) δ 3.45−3.55 (m, 4H, H-pip), 3.75 (t, J = 7 Hz, 2H, CH 2 ), 3.90−4.00 (m, 4H, H-pip), 4.55 (t, J = 7 Hz, 2H, CH 2 ), 6.45 (dd, J = 1.7 and 3.4 Hz, 1H, H-fur), 7.00 (dd, J = 0.8 and 3.4 Hz, 1H, H-fur), 7.50 (dd, J = 0.8 and 1.7 Hz, 1H, H-fur), 7.60 (s, 1H, H-pyrid).…”

“…14 Alkylation of 5 with 1-(2-methoxyphenyl)-4-(3-chloropropyl)piperazine (6a) 15 or 1-(2-chlorophenyl)-4-(3chloropropyl)piperazine (6b) 15 in dry ethanol in the presence of sodium hydroxide (method A) afforded compounds 3a and 3b, respectively, in moderate yield. Alternatively, 5 was alkylated with 1,2-dibromoethane under phase transfer catalysis, according to the procedure reported by Yamada, 16 to give intermediate 7a, which in turn was converted to final compounds 3c and 3d by reaction with 1-(2-methoxyphenyl)piperazine (8) or 1-(2-chlorophenyl)piperazine (9) (Na 2 CO 3 /isoamyl alcohol, method B) in 20-30% overall yield. R,ω-Dibromoalkanes having four to seven methylene groups were employed to prepare intermediates 7b-e (K 2 CO 3 / acetone, method C), from which compounds 3e-l were synthesized following method B. Analogously, compound 4d was prepared by direct alkylation of 10, 17 according to the procedure previously reported for the synthesis of 4a-c, 17 while pyridazinones 4e-l were obtained via intermediates 11a-d, in turn prepared by treatment of 10 with dibromoalkanes (method C).…”

Hydroxoiridium‐Catalyzed Hydroalkylation of Terminal Alkenes with Ureas by C(sp3)−H Bond Activation

“…Hydrolysis of 3 zr by aqueous KOH gave the corresponding amine, and then, treatment of the resulting amine with HCl in Et 2 O gave rac ‐Cinacalcet hydrochloride ( 4 ), which is a drug that acts as a calcimimetic agent (Scheme a) . The urea 3 ts , which shows an antisecretory and antiulcer activities, was prepared from 1,3‐dimethylurea ( 1 t ) and the N ‐allylpyridazinone 2 s in 90 % yield (Scheme b) …”

N-Heterocyclic Carbene-Catalyzed Oxidative Annulations of α,β-Unsaturated Aldehydes with Hydrazones: Selective Synthesis of Optically Active 4,5-Dihydropyridazin-3-ones and Pyridazin-3-ones

“…In addition, 4,5-dihydropyridazin-3-one compounds also have anticancer, anticonvulsant, and hypotensive activities, etc. Pyridazin-3-one derivatives, on the other hand, also are known to possess widespread and powerful pharmacologic properties, varying from antiulcer, antihistamine, antitumor, and anti-inflammatory activities to inhibitory activity to HIV-1 reverse transcriptase, phosphodiesterases, platelet aggregation, etc. Various substituted pyridazin-3-ones were reported to have insecticide, acaricide, and herbicide activities…”