The present invention describes a process for making CF
3
CH═CHF (HFO-1234ze). The process involves the addition of carbon tetrachloride (CCl
4
) to 1,2-dichloroethylene to form CCl
3
CHClCHCl
2
. The compound CCl
3
CHClCHCl
2
thus can then either be treated with HF to produce CF
3
CHClCHClF as the main product, or it can be converted to CCl
2
═CHCHCl
2
(1230za) by dechlorination. CCl
2
═CHCHCl
2
can be treated with HF such that the main product obtained is CF
3
CHClCHClF. CF
3
CH═CHCl may be produced as a by-product, but upon treatment with HF, it affords the compound CF
3
CHClCHClF. The desired compound, CF
3
CH═CHF (HFO-1234ze), is obtained as a trans/cis mixture by dehydrochlorination of CF
3
CH
2
CHClF or by dechlorination of CF
3
CHClCHClF.
该发明描述了一种制备CF3CH═CHF(
HFO-1234ze)的过程。该过程涉及将
四氯化碳(
CCl4)加入
1,2-二氯乙烯以形成CCl3CHClCHCl2。然后,可以将该化合物CCl3CHClCHCl2与
氢氟酸处理,产生CF3CHClCHClF作为主要产物,或者可以通过脱
氯反应将其转化为
CCl2═CHCHCl2(1230za)。 ═CHCHCl2可以与
氢氟酸处理,主要产物为CF3CHClCHClF。CF3CH═CHCl可能作为副产物产生,但经过
氢氟酸处理后,可以得到CF3CHClCHClF。所需的化合物CF3CH═CHF(
HFO-1234ze)可通过脱
氯反应CF3CH2CHClF或脱
氯反应CF3CHClCHClF得到其顺反异构体混合物。