| abstract |
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. |