| 摘要 |
PURPOSE:To efficiently obtain the subject compound useful as a boiler-cleansing agent, a plating additive, etc., under mild conditions by hydrogenating an oxalic acid diester with hydrogen in the presence of a solid catalyst produced by carrying copper metal and silver metal on a carrier in a gas phase. CONSTITUTION:The method for producing the glycolic acid ester comprises dissolving copper nitrate and silver nitrate in water, adding silica gel for a carrier to the solution, gradually dropping an preliminarily produced ammonium carbonate aqueous solution to the mixture, filtering out the produced precipitates, drying the separated precipitates at 40 deg.C for 12hr, reducing the dried precipitates in a hydrogen flow at 350 deg.C for 2hr, charging the produced solid catalyst comprising the copper metal and the silver metal carried on the carrier into a glass gas phase reaction tube, supplying hydrogen gas and an oxalic acid diester of formula: (COOR)2 (R is 1-6C lower alkyl) into the reaction tube, and simultaneously hydrogenating the oxalate diester at 237 deg.C under ordinary temperature in the gas phase, thus producing the objective glycolic acid ester in high selectively and in high yield. |
