89-64-5Relevant articles and documents
Theoretical and experimental evidence of the photonitration pathway of phenol and 4-chlorophenol: A mechanistic study of environmental significance
Bedini, Andrea,Maurino, Valter,Minero, Claudio,Vione, Davide
, p. 418 - 424 (2012)
Light-induced nitration pathways of phenols are important processes for the transformation of pesticide-derived secondary pollutants into toxic derivatives in surface waters and for the formation of phytotoxic compounds in the atmosphere. Moreover, phenols can be used as NO2 probes in irradiated aqueous solutions. This paper shows that the nitration of 4-chlorophenol (4CP) into 2-nitro-4-chlorophenol (NCP) in the presence of irradiated nitrate and nitrite in aqueous solution involves the radical NO2. The experimental data allow exclusion of an alternative nitration pathway by OH + NO2. Quantum mechanical calculations suggest that the nitration of both phenol and 4CP involves, as a first pathway, the abstraction of the phenolic hydrogen by NO2, which yields HNO2 and the corresponding phenoxy radical. Reaction of phenoxyl with another NO2 follows to finally produce the corresponding nitrated phenol. Such a pathway also correctly predicts that 4CP undergoes nitration more easily than phenol, because the ring Cl atom increases the acidity of the phenolic hydrogen of 4CP. This favours the H-abstraction process to give the corresponding phenoxy radical. In contrast, an alternative nitration pathway that involves NO 2 addition to the ring followed by H-abstraction by oxygen (or by NO2 or OH) is energetically unfavoured and erroneously predicts faster nitration for phenol than for 4CP.
Nitration method for aryl phenol or aryl ether derivative
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Paragraph 0050-0058, (2020/01/03)
The invention relates to a nitration method for an aryl phenol or aryl ether derivative. The method comprises the steps of stirring an aryl phenol or aryl ether compound, nitrate, trimethylchlorosilane (TMSCl) and a copper salt in an acetonitrile solution in air at room temperature, simultaneously, monitoring extent of reaction through a TLC dot plate, removing a solvent from a mixture by a rotaryevaporator after a substrate is consumed completely, and carrying out purification through a silica-gel column, thereby obtaining a nitroolefin derivative. Meanwhile, the selective mono-nitration orbis-nitration of the substrate can be achieved through controlling equivalent weight of the nitrate. Compared with the prior art, the nitration method disclosed by the invention has the advantages that the consumption of strong-acid substances is avoided, the reaction conditions are mild, the yield is high, the applicable range of the substrate is wide, reaction activity is free of obvious attenuation after an amplified reaction, and an excellent yield is still obtained, so that the method has an obvious industrial application value.
Melamine-(H2SO4)3/Melamine-(HNO3)3 Instead of H2SO4/HNO3: Benign System for Oxidation/Nitration Reactions from in situ NO2 +
Chehardoli, Gholamabbas,Azimi, Seyedeh Bahareh
, p. 589 - 594 (2019/11/16)
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