Liq. oxidn. of pseudo-cumene or durene - to trimellitic or pyromellitic acid using catalyst contg. cobalt, manganese, bromine and opt. zirconium

摘要

Oxidn. of pseudocumene (I) or durene (II) by molecular oxygen into trimellitic or pyromellitic acid resp. is effected in liquid phase in presence of a source of Co, a source of Mn plus a source of Br, and opt. a source of Zr, at 100-275 deg.C. The bromine is added in at least 2 steps, 10-35 wt.% of the total bromine being added in the first step and the rest is added in the last step, the temp. in the last step being 175-275 deg.C and that in the preceding step being 125-165 deg.C.