| 摘要 |
PROBLEM TO BE SOLVED: To obtain in a short time in high yield in an industrially advantageous way a cinnamic acid derivative useful as an antioxidant for foods by reaction of malonic acid or acetic anhydride with a benzaldehyde derivative in the presence of a specific catalyst. SOLUTION: The objective compound of formula II is obtained by reaction of (B) a compound of formula I (R<1> and R<2> are each H or a lower alkyl) with (C) malonic acid or acetic: anhydride in the presence of (A) activated silica gel (e.g. white carbon, or obtained by acidolysis of montmorillonite or calcium silicate). This reaction can be conducted without the need of using any solvent in a melt kept at a temperature higher than the melting point of the crystal body by thoroughly mixing powders of the components A, B and C followed by merely heating the powders. |
