Oxidation of nitrotoluenes with air using N-hydroxyphthalimide analogues as key catalysts

Nitrotoluenes are efficiently oxidized with air to the corresponding nitrobenzoic acids by the use of N-acetoxyphthalimide (NAPI) as a key catalyst. Thus, p- and m-nitrotoluenes under 10 atm of air in the presence of NAPI combined with Co(OAC)2 (0.5 mol%) and Mn(OAc)(2) (0.05 mol%) at 130degreesC afforded p- and m-nitrobenzoic acids in 81 and 92% yields, respectively. o-Nitrotoluene was oxidized to o-nitrobenzoic acid in 51% yield by the aid of NO(2). (C) 2003 Elsevier Science Ltd. All rights reserved.