| 摘要 |
PROBLEM TO BE SOLVED: To efficiently produce the subject derivative in high yield by reacting a specific benzaldehyde derivative with malonic acid in the presence of a base in a specific temperature range. SOLUTION: (A) A benzaldehyde derivative of formula I (R<1> to R<3> are each H, a halogen or a 1-3C alkoxy, with the proviso that R<1> to R<3> are simultaneously not H) (e.g. o-chlorobenzaldehyde) is reacted with (B) malonic acid in an amount of >=1 mol and <=3 mol, preferably >=1.5 mol and <=2 mol.% based on 1 mol component A in the presence of (C) a base in an amount of >=0.1 equivalent and <=1 equivalent, preferably >=0.3 equivalent and <=0.7 equivalent, preferably in a solvent (e.g. isopropanol) at 50-70 deg.C, preferably 60-65 deg.C, preferably for 8-12 hr to provide the objective derivative of formula II. |
