637-62-7Relevant articles and documents
Superoxo radical scavenging action by common analgesic drug paracetamol: A model kinetic study
Singh, Bula,Das, Ranendu Sekhar,Banerjee, Rupendranath,Mukhopadhyay, Subrata
, p. 266 - 271 (2013)
In acid perchlorate media ([H+] = 1.0-3.0 M), each mole of paracetamol, HOC6H4NHCOCH3 (APAP), at ambient temperature quantitatively reduces two mole of the metallo-superoxo complex, μ-superoxo-bis[pentaamminecobalt(III)]5+, [(NH3)5Co(III)(μ- O2)Co(III)(NH3)5]5+ (1). Here, complex 1 is reduced to [(NH3)5Co(OH2)]3+, Co2+, O2 and NH4+ and APAP itself is oxidised to quinone oxime and acetic acid. With a large excess of APAP over 1, the reduction follows first-order kinetics. The observed first-order rate constant (ko) increases linearly with increasing [H+] as well as with TAPAP (TAPAP being the analytical concentration of APAP). The protonated form of APAP, viz. APAPH+ seems to be the kinetically reactive reductant species. The enrichment of aqueous reaction media with D2O retards the reaction and thus it appears that the reaction proceeds through an electroprotic mechanism. A relatively small ΔH≠ (57 ± 2 kJ M 1) and moderately negative ΔS≠ (-68±8JK 1 M 1) supports a compact transition state.
Preparation method of P-benzoquinone dioxime
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Paragraph 0061-0070; 0078-0087; 0095-0104, (2021/12/07)
The preparation method of p-benzoquinone dioxime generates intermediate p-benzoquinone monooxime and byproduct alcohol under the action of an acid reaction promoter, and the intermediate is directly reacted with hydroxylamine hydrochloride to generate p-benzoquinone dioxime. The discharge of production waste water is reduced, and the requirement of green color production is met. The by-product ethanol obtained by nitrosation reaction can be finally recovered by distillation together with an organic solvent, so that the utilization rate of raw materials is improved. The whole synthesis process adopts an inert gas to isolate air, avoids the disproportionation and decomposition and intermediate of ethyl nitrite, reduces the generation of side reactions, improves the conversion rate of the reaction, and further improves the yield and purity of the benzoquinone dioxime, the yield is 85.0% - 95.0%, the purity ≥ 99.0 wt % and the melting point are 250 °C - 255 °C.
The Diels-Alder reactions of para-benzoquinone nitrogen-derivatives: An experimental and theoretical study
Uliana, Marciana P.,Servilha, Bruno M.,Alexopoulos, Olga,De Oliveira, Kleber T.,Tormena, Cláudio F.,Ferreira, Marco A.B.,Brocksom, Timothy J.
, p. 6963 - 6973 (2015/11/09)
An experimental and theoretical study of the comparative reactivity and selectivity of the Diels-Alder reactions of para-benzoquinones and three nitrogen derivatives have been performed. The mono-oximes derivatives do not react under the tested reaction conditions, whereas the tosylated mono-oximes react slowly. However, the mono N-tosyl imines show excellent reactivity, and superior to the parent parabenzoquinones. DFT calculations support these experimental results.