| abstract |
Pure title cpds. of formula (I): are prepd. from their mixts. with isomers of formula (II): (where R1 is an aliphatic, cycloaliphatic, araliphatic or aromatic residue; R2 is H or an aliphatic residue, and X is halogen) by extracting (II) from the mixt. with aliphatic halohydrocarbons, alkanols and/or ethers. After the extraction, undissolved (I) can be sepd. off by filtration, and (II) can be isolated from the extract. (I) and (II) are plant-protection agents (herbicides) and inters. in synthesis of e.g. dyes and plant-protection agents. |