Patent ID: 8258355

Claim:
A process for preparing 1,1,2,3-tetrachloro-1-propene comprising: chlorinating CH 2 ═CHCH 2 Cl in the presence of Cl 2 gas to form a first precursor product comprising CH 2 ClCHClCH 2 Cl, wherein the selectivity for CH 2 ClCHClCH 2 Cl is at least about 90%; catalytically dehydrochlorinating at least a portion of the CH 2 ClCHClCH 2 Cl of said first precursor product to form a second precursor product comprising CH 2 ClCCl═CH 2 ; chlorinating at least a portion of said CH 2 ClCCl═CH 2 in the presence of Cl 2 gas to form a third precursor product comprising CH 2 ClCCl 2 CH 2 Cl; dehydrochlorinating in the vapor phase at least a portion of said CH 2 ClCCl 2 CH 2 Cl and in the presence of a first catalyst to produce a first intermediate product comprising CHCl═CClCH 2 Cl; chlorinating at least a portion of the CHCl═CClCH 2 Cl of said first intermediate product to form a second intermediate product comprising CHCl 2 CCl 2 CH 2 Cl; and dehydrochlorinating at least a portion of the CHCl 2 CCl 2 CH 2 Cl from said second intermediate product in the vapor phase and in the presence of a second catalyst to form a final product comprising CCl 2 ═CClCH 2 Cl.