摘要 |
<p>Acetic anhydrde is prepared by reacting, at elevated temperature, methyl acetate or dimethyl ether with carbon monoxide in the presence of an effective amount of a catalyst which comprises: (1) cobalt, (2) a compound containing at least one quaternary nitrogen or phosphorus atom and (3) a source of iodide or bromide wherein the atomic ratio of iodide or bromide to cobalt is from 0.5:1 to 5:1. The compound containing at least one quaternary nitrogen or phosphorus atom can optionally by generated in situ by a quartemisation reaction.</p> |