| 摘要 |
1,175,240. Acetoacetic acid esters. FARBWERKE HOECHST A.G. 21 Dec., 1967 [24 Dec., 1966], No. 58147/67. Heading C2C. Acetoacetic acid esters are prepared by reacting diketene with an aliphatic or cycloaliphatic alcohol that has a boiling point below 140‹ C., in the presence of, as catalyst, a basic compound and/or a betaine and under superatmospheric pressure. Examples of the basic catalyst include tertiary amines of the formula NR 3 in which each R stands for the same or different aliphatic, cycloaliphatic, araliphatic, aromatic or alkanol radicals; cyclic tertiary amines, quaternary ammonium salts, tertiary phosphines, di- and tri-basic sodium phosphates and other inorganic salts that have alkaline reactions in aqueous solution. A preferred apparatus for carrying out the process of the invention comprises a subdivided reactor in which the reaction mixture is boiled under reflux. |
