Process for preparing oxoisophorone in presence of one or more acetate salts

摘要

Preparation of 3,5,5-trimethyl-cyclohex-2-ene-1,4-dione (I) comprises oxidation of 3,5,5-trimethyl-cyclohex-3-en-1-one (II) with molecular oxygen in the presence of a metal salen complex catalyst (III) and in the additional presence of an acetate salt (IV). Preparation of 3,5,5-trimethyl-cyclohex-2-ene-1,4-dione (I) (i.e. oxoisophorone) involves oxidation of 3,5,5-trimethyl-cyclohex-3-en-1-one (II) ( beta -isophorone) with molecular oxygen in the presence of a solvent, a base and a manganese salen complex of formula (III) as catalyst. The reaction is carried out in the additional presence of a metal acetate salt of formula (IV). R1-R8 = H, halo, NO2, COR9, OCOR9, COOR9, SO2R9 or SO3R9; R9 = H or 1-4C alkyl; M = Mn(II), Mn(III)+.X-, Fe(II), Fe(III)+.X-, Cu(II) or Ru(II); X- = counter-anion for metals in the III oxidation state; R10-R12 = H, halo or 1-4C alkyl; Y = NH4+ or a mono- to tetravalent cation of a Group I-IV non-transition metal and m = 1-4.