Synthesis and Conformational Analysis of [3-(6-Chloropyridazin-3-yl)-3,4-Dihydropyridazino[4,5-b]Quinoxalin-2(1Н)-yl](Phenyl)Methanone

Synthesis and isomerism of 2-benzoyl-5,12-dimethoxy-3-heteryl-1,2,3,4-tetrahydronaphtho[2,3-g]phthalazine-6,11-diones

“…As a continuation of our previous studies on the cycloconde nsat ion of hydrazid es and 1,4-bielectrophiles [10], we studied the reaction of 2,3-bis(bromomethyl)-1,4-dimethoxyanthracene-9,10-dione 1 with several hydrazides 2a,b,c. Cyclocondensation of hydrazides 2a,b,c occurred in DMF at room temperature in the presence of two equivalents of potassium carbonate as a base.…”

“…The results of LC-MS showed that the products formed with the corresponding substituent have the same molecular weight values corresponding to the above formula, but they exhibit some differences in NMR spectra. These products contain a six-membered pyridazine ring with benzoyl and heterocyclic substituents similar to the compounds that were previously studied [10], so we assumed the existence of similar atropisomers due to the complicated rotation of N-(C=O) bond and heterocyclic substituent.…”

“…The study of the structure of atropisomers in solution for structurally similar substances based on the analysis of experimental and calculated 1 H NMR spectra at different temperatures is described elsewhere [9,10]. The equilibrium between atropisomers for the compounds reported in work [9] is observed at room temperature that can be explained by the low stiffness of the cycle.…”

“…The equilibrium between atropisomers for the compounds reported in work [9] is observed at room temperature that can be explained by the low stiffness of the cycle. In our previous studies of the cycloaddition of 2,3-bis(bromomethyl)quinoxaline [10], isomeric forms were isolated as individual substances.…”