| abstract |
Process for oxidatively carbonylating toluene to toluic acid, at least 50 mol % of the toluic acid being the p-isomer, said process comprising contacting and reacting, at 110 DEG -250 DEG C., at a pressure of at least 500 psi (3.45 MPa), toluene, carbon monoxide, oxygen and the catalyst ingredients consisting essentially of (a) a compound of rhodium or iridium; (b) a sulfur oxy-acid or a Group Ia or IIa metal salt of a sulfur oxy-acid; (c) a sulfur oxy-acid or sulfur oxy-acid mixture having a Hammett acidity value (-Ho) of greater than 7.0; and (d) a cupric salt of a sulfur oxy-acid; said catalyst ingredients containing 0.3-30 mol % of (a) and 70-99.7 mol % of (b+c+d), with the molar ratios (b/a) and (c/a) each being at least 2 and the molar ratio (d/a) being at least 0.5, and recovering toluic acid. |