| 摘要 |
<p>The invention relates to the preparation of optically active aryloxyalkanoic acid derivatives of the formula <IMAGE> in which Ar represents an optionally substituted phenyl, naphthyl, phenoxy or pyridyloxy radical, R represents a C1-C4-alkyl radical and A represents a -COOR1, <IMAGE> or -CO-Z radical, Z being halogen. It consists in reacting an aqueous or aqueous-organic solution of an optically active alkali metal salt of a 2-halogeno-alkanoic acid with an aqueous solution of an alkali metal salt of the phenol of the formula Ar-OH at an elevated temperature under a pressure less than the vapor pressure of water at the chosen temperature. It permits the preparation of aryloxyalkanoic acid derivatives with a very high content of the isomer having the D configuration, which can be used as herbicides.</p> |
