Decomposition mechanism of annelated triazinones bearing the para-nitrophenyl group

Worzakowska, Marta; Sztanke, Małgorzata; Sztanke, Krzysztof

doi:10.1016/j.jaap.2020.104856

Cited by 5 publications

(3 citation statements)

References 32 publications

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“…Nevertheless, there are only few scientific reports on the thermal analysis of drugs structurally based on the 1,2,4-triazine system (lamotrigine-used for the treatment of epilepsy and bipolar disorder) [6,7] or with the 1,2,4-triazin-4(3H)-one nucleus incorporated into the bicyclic structure (vardenafil-used for the treatment of erectile dysfunction) [8]. However, surveys have shown that the thermal stability and decomposition studies have been carried out on many condensed 1,2,4-triazines containing some functional moieties, including those with importance in material science [8] and pharmaceutical science [9][10][11][12]. On the other hand, there is a limited number of scientific reports on the thermal analysis of small molecules containing the acetohydrazide functional group.…”

Section: Introductionmentioning

confidence: 99%

Application of Simultaneous and Coupled Thermal Analysis Techniques in Studies on the Melting Process, Course of Pyrolysis and Oxidative Decomposition of Fused Triazinylacetohydrazides

Worzakowska,

Sztanke,

Sztanke

2024

IJMS

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The effect of the structure of promising antioxidant agents with prospective medical use, i.e., unsubstituted and para-substituted annelated triazinylacetic acid hydrazides, on their melting points, thermal stabilities, pyrolysis and oxidative decomposition stages and the type of volatiles emitted under heating with the use of DSC and TG/DTG/FTIR/QMS methods was evaluated and discussed. The melting point of the investigated compounds increased with an enhanced number of electrons (directly correlated with their molecular weight). Melting enthalpy values were determined and presented for all the studied compounds. The pyrolysis and oxidative decomposition processes of the analysed molecules consisted of several poorly separated stages, which indicated a multi-step course of the decomposition reactions. It was found that the thermal stability of the tested compounds depended on the type of substituent at the para position of the phenyl moiety or its absence. In both atmospheres used (air and helium), the thermal stability increased in relation to R as follows: -CH3 ≤ -OCH3 < -H < -OC2H5. In an inert atmosphere, it was higher by approx. 8–18 °C than in an oxidative atmosphere. The pyrolysis was connected with the emission of NH3, HCN, HNCO, HCONH2, HCHO, CO2, CO and H2O in the case of all the tested compounds, regardless of the substituent attached. In the case of the derivative containing the para-CH3 group, para-toluidine was an additional emitted aromatic product. In turn, emissions of aniline and alcohol (methanol or ethanol) for compounds with the para-OCH3 and para-OC2H5 groups, respectively, were confirmed. In oxidative conditions, the release of NH3, NO, HCN, HNCO, HCONH2, CO2, H2O and cyanogen (for all the compounds) and para-toluidine (for the para-CH3 derivative), aniline (for para-OCH3, para-OC2H5 and unsubstituted derivatives) and acetaldehyde (for the para-OC2H5 derivative) were clearly observed. No alcohol emissions were recorded for either compound containing the para-OCH3- or para-OC2H5-substitututed phenyl ring. These results confirmed that the pyrolysis and oxidative decomposition of the investigated annelated triazinylacetohydrazides occurred according to the radical mechanism. Moreover, in the presence of oxygen, the reactions of volatiles and residues with oxygen (oxidation) and the combustion process additionally proceeded.

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Section: Introductionmentioning

confidence: 99%

Application of Simultaneous and Coupled Thermal Analysis Techniques in Studies on the Melting Process, Course of Pyrolysis and Oxidative Decomposition of Fused Triazinylacetohydrazides

Worzakowska,

Sztanke,

Sztanke

2024

IJMS

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“…Furthermore, there are several scientific articles concerning the thermal analysis of pharmacologically or energetically important 1,2,4-triazines as well as 1,2,4-triazines condensed with five-membered azole systems [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Masłowska and Jaroszyńska studied the stages of thermal decomposition of the pharmacologically active diethyl 2,2′-(3-thioxo-2,3-dihydro-1,2,4-triazine-5,6-diyl)diacetate [ 12 ].…”

Section: Introductionmentioning

confidence: 99%

“…Bartyzel et al, studied the thermal properties and mechanism of thermal decomposition of fused (1,2,4-triazin-3-yl)carbohydrazides with significant antitumor activities [ 18 ]. Worzakowska et al, investigated the thermal stability range and thermal properties of anticancer active condensed 1,2,4-triazinones possessing the nitrophenyl or trifluoromethyl moiety and explained their decomposition mechanism by means of combined thermal techniques [ 19 , 20 ]. Łyszczek et al [ 21 ] and Bartyzel et al [ 22 ] studied the thermal properties and thermal stability ranges for pharmacologically active condensed 1,2,4-triazinones bearing an additional five-membered heteroaromatic substituent, such as thienyl or furanyl.…”

Section: Introductionmentioning

confidence: 99%

Experimental Studies on the Thermal Properties and Decomposition Course of a Novel Class of Heterocyclic Anticancer Drug Candidates

Worzakowska

Sztanke

2023

IJMS

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The experimental studies on the thermal properties and decomposition course of a novel class of potential anticancer drugs (1–5) containing in their heterobicyclic structures the asymmetrical triazine template were performed with the use of differential scanning calorimetry (DSC) and simultaneous thermogravimetry/differential scanning calorimetry (TG/DTG/DSC) coupled online with Fourier transform infrared spectroscopy (FTIR) and quadrupole mass spectrometry (QMS) in inert and oxidizing conditions. All the compounds were thermally characterized in detail for the first time in this article. The DSC studies proved that the melting points of the tested compounds depended on the position and type of the substituent at the phenyl moiety, whereas they did not depend on the furnace atmosphere. All the tested polynitrogenated heterocycles proved to be molecules with high thermal stability in both atmospheres, and most of them (1, 3–5) were more stable in oxidizing conditions, which indicated the formation of a more thermally stable form of the compounds when interacting with oxygen. The simultaneous TG/FTIR/QMS analyses confirmed that their pyrolysis process occurred in one main stage resulting in the emission of volatiles such as NH3, HNCO, HCN, CO, CO2, H2O, NO2, aromatic amine derivatives, alkenes (for compounds 1–5), and HCl (for the compound 5). On the other hand, the oxidative decomposition process was more complicated and proceeded in two main stages leading to the emission of NH3, CO2, CO, HCN, HNCO, H2O, some aromatics (for compounds 1–5), HCl (for compounds 3–5) as well as the additional volatiles such as N2, NO2, NH2OH, and (CN)2. The type of the formed volatiles indicated that the decomposition process of the studied heterocycles under the influence of heating was initiated by the radical mechanism. Their decomposition was related to the symmetric cleavage of C–N and C–C bonds (inert conditions) and additional reaction of the volatiles and residues with oxygen (oxidizing conditions).

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Pyrolysis and oxidative decomposition mechanism of trifluoromethylated fused triazinones

Worzakowska

Sztanke

2021

Journal of Analytical and Applied Pyrolysis

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Decomposition mechanism of annelated triazinones bearing the para-nitrophenyl group

Cited by 5 publications

References 32 publications

Application of Simultaneous and Coupled Thermal Analysis Techniques in Studies on the Melting Process, Course of Pyrolysis and Oxidative Decomposition of Fused Triazinylacetohydrazides

Application of Simultaneous and Coupled Thermal Analysis Techniques in Studies on the Melting Process, Course of Pyrolysis and Oxidative Decomposition of Fused Triazinylacetohydrazides

Experimental Studies on the Thermal Properties and Decomposition Course of a Novel Class of Heterocyclic Anticancer Drug Candidates

Pyrolysis and oxidative decomposition mechanism of trifluoromethylated fused triazinones

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