21232-52-0Relevant academic research and scientific papers
FORMATION OF METHOXY-SUBSTITUTED AZOXYBENZENES IN THE REDUCTION OF NITROARENES IN BASIC METHANOL-TOLUENE SOLUTIONS
Prato, Maurizio,Quintily, Ugo,Scorrano, Gianfranco
, p. 421 - 426 (2007/10/02)
The reduction of nitroarenes in boiling methanol-toluene containing KOH affords high yields of the corresponding azoxy derivative and small amounts of other azoxy compounds containing one or more OCH3 groups linked to the aromatic rings.It has been proved that the reaction does not occur via formation of methoxy-nitroarenes and their further reduction.The reaction is proposed to involve: a) formation of a Meisenheimer complex by attack of the methoxide ion on the nitroarene; b) abstraction of a proton from the Meisenheimer complex by a methoxide ion to form a dianion; c) protonation of the dianion with concurrent elimination of OH to form the nitroso-methoxy arene which is finally reduced to the methoxy-azoxy derivative.It is proposed that the dianion is the electron-donating species to start the reduction of nitro- and nitrosoarenes.
The synthesis of anilines or azoxybenzenes from the reduction of nitrobenzenes in basic alcoholic media
Prato, Maurizio,Quintily, Ugo,Scapol, Lucia,Scorrano, Gianfranco
, p. 99 - 102 (2007/10/02)
Reduction of substituted nitrobenzenes in alkaline alcoholic solutions affords, depending on the experimental conditions used, either anilines or azoxybenzenes in good yields.In the presence of a methylketone, such as acetophenone, the reaction of nitroarenes with aqueous KOH in 2-propanol provides the corresponding anilines in high yields (80-90 percent).On the other hand, when the reaction is carried out in the CH3OH/toluene/KOH system, in the absence of methylketones, the azoxyderivatives are isolated in 70-90 percent yield.
Reduction of Nitroarenes to Anilines in Basic Alcoholic Media
Prato, Maurizio,Quintily, Ugo,Scorrano, Gianfranco
, p. 1419 - 1424 (2007/10/02)
Substituted nitrobenzenes are reduced by alkoxide ions in alcohols to the corresponding azoxy and aniline derivatives.The reaction leading to anilines has been investigated in detail.Two different processes have been identified, both initiated by the condensation between the nitrosoarene intermediate (the first product of the reduction reaction) and the product of oxidation of the solvent.The imino derivative thus formed (ArN=CH-COR) may either undergo hydrolysis (to aniline) or form, through a series of redox processes, compounds containing the ArNH-CO moiety.These are also hydrolysed to anilines in a slower reaction.
