148750-50-9

Upstream product

• 933-76-6 4,5-dichloro-2-methyl-3(2H)-pyridazinone 
• 100-46-9 benzylamine 
• 144172-56-5 3-benzylamino-1-(p-methoxyphenyl)-1-propanol 
• 181474-90-8 5-{Benzyl-[3-hydroxy-3-(4-methoxy-phenyl)-propyl]-amino}-4-chloro-2-methyl-2H-pyridazin-3-one 

Downstream Products

• 136353-33-8 3-Benzyl-2-[(Z)-4-ethoxy-phenylimino]-6-methyl-2,3-dihydro-6H-thiazolo[4,5-d]pyridazin-7-one 
• 136353-45-2 3-Benzyl-6-methyl-2-[(Z)-naphthalen-1-ylimino]-2,3-dihydro-6H-thiazolo[4,5-d]pyridazin-7-one 
• 136353-44-1 3-Benzyl-2-[(Z)-4-chloro-phenylimino]-6-methyl-2,3-dihydro-6H-thiazolo[4,5-d]pyridazin-7-one 

Relevant academic research and scientific papers

Lipophilicity of aminopyridazinone regioisomers

Ten pairs of pyridazinone regioisomers were prepared, and their lipophilicity was described by the logarithm of the octanol/water partition coefficient (log P) determined experimentally and calculated with prediction methods. The 4- and 5-(substituted amino)-3(2H)-pyridazinone regioisomers were synthesized by nucleophilic substitution of one of the chloro atoms of 4,5-dichloro-2-methyl-3(2H)-pyridazinone or its 6-nitro derivative. Structures of new compounds were proven by spectroscopic methods. The experimental log P values were obtained by a shake flask method in octanol and a Soerensen buffer (pH 7.4) solvent system. A consequent difference was found in the lipophilicity of regioisomers. For each isomer pair, the log P value of the 4-isomer was significantly (average by 0.75 log unit) higher than that of the 5-isomer. Some quantum chemical calculations as well as X-ray analysis of two pairs of regioisomers were also carried out to gain insight into the structural differences of regioisomers. The log P values were calculated by the fragmental approach KOWWIN and a QSPR analysis (3DNET). The a priori KOWWIN gave poor agreement, but with the programs KOWWIN with EVA (experimental value adjusted) and 3DNET, the results were generally in agreement with experiment.

Synthesis of some novel 2-phenylpyridazino[4,5-b][1,5]thiazepines

Synthesis of some derivatives of the pyridazino[4,5-b][1,5]thiazepine ring system is reported. Thus, 5-benzyl-8-methyl-2-phenyl-2,3,4,5-tetrahydro-5H-pyridazino[4,5-b][1,5] thiazepin-9(8H)-one (5) was prepared by an intramolecular S-alkylation reaction, whereas the thiazepine ring of sulfone analogue 21, and that of the novel tricyclic pyrrolidino fused ring system 22 was elaborated by an intramolecular C-alkylation reaction. Unexpected formation of bicyclic pyrido- and thiazine fused pyridazine systems are also discussed.

Kinetic and Theoretic Aspects of Regiochemistry in the Reaction of 4,5-Dihalo-3(2H)-pyridazinones with Benzylamines

Regioselectivity of nucleophilic substitution reactions of 4,5-dihalo-3(2H)-pyridazinones (1a-d) with benzylamines was studied under different conditions.Second-order kinetics were obtained for reactions of 1a with benzylamine in ethanol-d6 and toluene-d8 as well.Experimental results obtained were interpreted on the bases of Klopman-Salem equation and analyses of the reaction paths.

Conversion of Dipyridazinothiazines into Dipyridazinopyrroles through a Base-Induced Extrusion of Sulfur

A novel ring contraction for the conversion of 2,7-disubstituted 10H-dipyridazinothiazine-1,6-(2H,7H)-diones (4'a-c) into the corresponding 2,6-disubstituted 9H-dipyridazinopyrrole-1,5(2H,6H)-diones (7'a-c), through a ba