Process for producing 1,1,2,3-tetrachloropropene
AssigneeMonsanto Company
InventorScott S. Woodard
Life of this patent
Estimating the term…
Abstract
A process is disclosed for preparing 1,1,2,3-tetrachloropropene comprising allylic rearrangement of 2,3,3,3-tetrachloropropene using a substantially anhydrous ferric chloride catalyst. Alternatively, 1,1,2,3-tetrachloropropene is prepared by dehydrochlorination of 1,1,1,2,3-pentachloropropane using a ferric chloride catalyst. Process schemes commencing with the preparation of the precursor 1,1,1,3-tetrachloropropane by reaction of ethylene with carbon tetrachloride are also disclosed.
Claims5
A process for producing 1,1,2,3-tetrachloropropene comprising the steps of:
- preparing 1,1,1,3-tetrachloropropane by reacting ethylene with carbon tetrachloride in the presence of both a source of metallic iron that is effective as an activator for the reaction, and a promoter for the reaction, said promoter being selected from trialkyl phosphites;
- dehydrochlorinating said 1,1,1,3-tetrachloropropane to produce a mixture of 1,1,3- and 3,3,3-trichloropropenes;
- chlorinating at least one of the trichloropropenes obtained by said dehydrochlorination of 1,1,1,3-tetrachloropropane to produce 1,1,1,2,3-pentachloropropane;
- dehydrochlorinating the 1,1,1,2,3-pentachloropropane to produce a mixture of 1,1,2,3- and 2,3,3,3-tetrachloropropenes;
- and
- contacting the mixture of tetrachloropropenes with an allylic rearrangement catalyst provided by substantially anhydrous ferric chloride, thereby converting the 2,3,3,3-tetrachloropropene content thereof to 1,1,2,3-tetrachloropropene.
A process for producing 1,1,2,3-tetarchloropropene comprising the steps of:
- preparing 1,1,1,3-tetrachloropropane by reacting ethylene with carbon tetrachloride in the presence of both a source of metallic iron that is effective as an activator for the reaction, and a promoter for the reaction, said promoter being selected from the group consisting of trialkyl phosphites and phosphorus (V) compounds containing a phosphoryl group;
- dehydrochlorinating said 1,1,1,3-tetrachloropropane to produce a mixture of 1,1,3- and 3,3,3-trichloropropenes;
- chlorinating at least one of the trichloropropenes obtained by said dehydrochlorination of 1,1,1,3-tetrachloropropane to produce 1,1,1,2,3-pentachloropropane;
- and
- contacting said 1,1,1,2,3-pentachloropropane with a catalytic proportion of substantially anhydrous ferric chloride, thereby effecting dehydrochlorination of the 1,1,1,2,3-pentachloropropane to 1,1,2,3-tetrachloropropene.
Dependencies are inferred from the claim text.