| 摘要 |
<p>The present invention provides for an improved practical process for producing DDTr-free p,p min -dicofol and its formulations substantially free of the practically inactive o-p min -dicofol comprising either directly recrystallizing technical dicofol from a suitable solvent such as acetic acid or alkanes, or alternatively preparing the p,p min -dicofol by the steps of (a) dehydrohalogenating technical DDT to give DDE; (b) chlorinating DDE to give Cl-DDT; and (c) hydrolyzing Cl-DDT to dicofol, wherein the technical DDT is initially recrystallized from a suitable solvent such as lower alkyl alcohols and then recrystallizing the resulting p,p min -dicofol from a suitable solvent such as acetic acid or alkanes.</p> |
