| 摘要 |
PURPOSE:To safely obtain methacrylic acid or its derivative under mild conditions in reduced process number and good yield. CONSTITUTION:A propionic acid or its derivative expressed by the formula CH3-CH2-CO2-R. (R is hydrogen atom, alkyl, aralkyl, aryl or acyl) is made to react with formaldehyde in the presence of a Lewis acid catalyst in a liquid phase. As the Lewis acid catalyst, an alkoxide, an aryl oxide, a carboxylate, a halide, an oxide, etc., of Al, Cu, Sn or Zn is used. The reaction is carried out at about 100-250 deg.C for 0.5-10hr. Aldol reaction smoothly proceeds by the catalyst and the corresponding methacrylic acid or its derivative of the formula CH2=C(CH3)-CO2-R is produced. |
