| 摘要 |
PURPOSE:To suppress generation of by-product having high boiling point and increase yield of the subject compound by keeping diols in hydrogenating reaction zone below a specific concentration in a production of lactones with hydrogenating dicarboxylic acids in liquid phase in the presence of ruthenium catalyst. CONSTITUTION:Dicarboxylic acid, dicarboxylic acid anhydride and/or dicarboxylate 4 is hydrogenated in a reactor 1 in the presence of ruthenium catalyst to produce lactones. In said process, concentration of diols generated by hydrogenation of raw material in said reacting zone 1 is kept <=5wt.%, preferably <=3wt.% by, for instance, a method in which a part 10 of reacted solution is separated from hydrogenating reaction zone 1 and distilled in a tower 8 to separate catalyst solution and diols, then only catalyst solution is circulated to said reacting zone 1, to-suppress generation of by-product having high boiling point owing to diols, thus yield of the objected compound is increased to industrially advantageously obtain the objected compound from said raw material. |
