PROCESS FOR PREPARING OXALIC ACID DIESTERS

摘要

This invention relates to an improved process for preparing a diester of oxalic acid by the vapor (or gaseous) phase catalytic reaction of carbon monoxide with an ester of nitrous acid in the presence of a catalyst composed of a platimun-group metal or a salt thereof supported on a solid carrier which is alumina having a specific surface area of not more than 90 m2/g. According to this process, the diester of oxalic acid can be produced at a high space time yield (based on the platinum-group metal) and high selectivity with reduced formation of a carbonic acid diester and carbon dioxide as by-products. A further advantage of this process is that the amount of the platinum-group metal used can be decreased and it can be easily recovered.