Abstract
The preparation of 1-chloro-2-iodoperfluorocycloalkenes was achieved with a short reaction time and a high yield when the starting compound was iodinated via the metalation process using an alkyllithium reagent. Especially, the high yield of 1-chloro-2-iodo-perfluorocyclohexene was obtained when 1,2-dichloroperfluorocyclohexene was iodinated via the same reaction conditions. The coupling reaction of 1,2-dihaloperfluorocycloalkenes was also achieved with a lower reaction temperature and a shorter reaction time when the equal slurry mixture of fluorocycloolefines and DMF was reacted at a high pressure in a sublimer. The yield of the coupling product was greatly improved by this process. For a typical example, the coupling reaction of the 1-chloro-2-iodotetrafluorocyclobutene was proceeded with a higher yield of the product than that of the reported reaction, when the present method was adopted. A plausible reaction mechanism of the present coupling reactiont was proposed and the physical characteristics of the coupling product were confirmed.
1-chloro-2-iodoperfluorocycloalkenes를 종전에는 DMF 용매속에서 KI를 사용하여 Halogen 교환반응에 의하여 합성하였으나 alkyllithium으로 금속교환반응을 통하여 iodination함으로써 반응시간이 단축되던지 특히 1,2-dichloroperfluorocyclohexene의 경우에는 더 높은 수득률의 1-chloro-2-iodoperfluorocyclohexene을 얻을 수 있었다. 그리고 1,2-dihaloperfluorocycloalkenes의 coupling 반응도 fluorocycloolefins과 동분을 DMF와 혼합하여 slurry를 만들어 이것을 sublimer속에서 감압하에 반응시키므로서 반응시간과 온도를 낮출 수 있었으며 생성물의 수득률도 많이 증가시킬 수 있었다. 대표적인 예로서 1-chloro-2-iodotetrafluorocyclobutene의 coupling 반응에 있어서는 종전에 비해서 더 높은 수득률의 coupling product를 얻을 수 있었다. 한편 coupling반응이 가능한 기구를 검토하고 그 생성물의 물리적 성질을 측정하여 확인하였다.