摘要 |
<p>A method of preparing compounds of the formula: <IMAGE> (I.) wherein a novel palladium catalyst system is utilized comprising palladium together with C1-2COO- ligands and halo ligands wherein the molar weight percent based on total ligand molar weight, of the C1-2COO- ligand is from 30 to 60%; and wherein the ratio of the total molar weight of the ligands to the molar weight of palladium utilized is from 4:1 to 10:1; and a catalyst regeneration portion comprising from 0.1 to 8.0 parts of phosphomolybdenovanadic acid per part of palladium catalyst, and at least 20 parts of a solubilizing agent selected from ethylene carbonate, propylene carbonate, and sulfolane, per part of palladium catalyst.</p> |