Oxidation of arylamines, arylhydroxylamines and other derivatives 153Table 4.2 Oxidation of arylamines with peroxycarboxylic acids
NH 2NO 2NH 2
O 2 N NO 2NO 2
NH 2
CH 3 CO 3 HOCH 3NH 2
SO 3 HNH 2
CH 3NH 2NH 2NH 2
NO 2CF 3 CO 3 HNO 2NO 2NO 2
O 2 N NO 2NO 2
NO 2OCH 3NO 2
SO 3 NaNO 2
CH 3NO 2NO 2NO 2
NO 2Entry Substrate Conditions Product Yield (%)2516382164maleic anhydride,
90 % H 2 O 2 , CH 2 Cl 2
(HO 2 C-CH=CH-CO 3 H)8716674165CHCl 3 , H 2 SO 4 (cat),
Ac 2 O, 90 % H 2 O 2 , reflux12435a5b6a6b7 9216890 % H 2 O 2 , (CF 3 CO) 2 O,
CH 2 Cl 2 , reflux^86167891679216781167(66)(68)(72)(70)(74)(76)(78)(67)(69)(73)(71)(75)(77)(79)90 % H 2 O 2 , CF 3 CO 2 H,
CH 2 Cl 2 , reflux90 % H 2 O 2 , (CF 3 CO) 2 O,
CH 2 Cl 2 , reflux90 % H 2 O 2 , CF 3 CO 2 H,
CH 2 Cl 2 , reflux- 30 % H 2 O 2 , CH 3 CO 2 H
70–75 °C - NaHCO 3
These solutions readily oxidize nitroanilines to the corresponding dinitrobenzenes but are
unable to oxidize amines of lower basicity like the dinitroanilines.^163 ,^164 Peroxyacetic acid
is well suited for the oxidation of arylamines containing strong electron-donating groups
(Table 4.2, Entry 2). Stronger oxidants like peroxytrifluoroacetic acid rapidly degrade such
substrates and give rise to various phenolic by-products. Peroxyacetic acid is also the reagent
of choice for the oxidation of some condensed ring arylamines (Table 4.2, Entry 1).^163
The reagent prepared from the reaction of 30 % hydrogen peroxide with glacial acetic acid
also contains peroxyacetic acid but the main product of arylamine oxidation is usually the
corresponding nitroso compound.^169 ,^170 On heating with an excess of this reagent the nitro
compound is usually obtained.^165 ,^169