Abstract
A simple and mild process for oxidation of xylenes to phthalic acids using N-hydroxyphthalimide/O2/HNO3 in an ionic liquid, wherein the ionic liquid can be successfully recovered and reused, is described.
ACKNOWLEDGMENT
Financial support from the Petrochemical Research and Technology Company of Iran is gratefully acknowledged.
Notes
a 2 mmol p-xylene, HNO3, O2, 1.48 g bmim[OMS], 110°C, 1 atm, 6 h.
b GC conversion.
c Isolated yield and selectivity by weight of terephthalic acid to p-xylene and product mixture.
d 1 mL of EtOAc was added to the IL.
e 1 mL CHCl3 was added to the IL.
f 3 mol% AIBN was used as initiator.
g Tetramethylpyrrolidine N-oxide (TEMPO) was used as initiator.
h NHPI was used as initiator. Recycling experiment for [bmim]OMS.
i NHPI was used as initiator.
j H2O2 30% was used as the oxidizing agent.
a 40°C, 6 h.
b 60°C, 4 h.
c 110°C, 6 h.
d T, terephthalic acid; I, isophthalic acid; P, phthalic acid.