| 摘要 |
PURPOSE:To efficiently obtain the subject compound useful as a raw material, etc., for producing methyl methacrylate by catalytically reacting an alpha- hydroxycarboxamide with water in the presence of a monoclinic high-surface area solid acid catalyst composed of an inorganic acid and a hexagonal rare earth phosphate. CONSTITUTION:A catalyst bed 4 of a reactional tube 5 made of Pyrex(R) glass is filled with a solid acid catalyst prepared by heating a rare earth phosphate of a hexagonal structure in a solution of an inorganic acid, its salt and/or ester at a molar ratio of the inorganic acid content in the solution of the inorganic acid, its salt and/or ester to the rare earth phosphate of the hexagonal structure within the range of 0.5-400 at 60-200 deg.C and an evaporation part 3 is filled with fused alumina balls. The reactional tube 5 is then fixed in an electric furnace and connected to a reactional solution receiver 6 cooled with a dry ice trap 7. An alpha-hydroxycarboxamide expressed by the formula (R1 and R2 are H or 1-4C alkyl) and water are bed subsequently from a raw material feed pipe 1 and brought into contact with the solid acid catalyst to afford the objective alpha,beta-unsaturated carboxylic acid. |
