Process for rearranging allylic geminal dihalogen compounds
AssigneeDowElanco
InventorPeter Langensee
Life of this patent
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Abstract
Cis- and trans-1,3-dichloropropenes and their homologs and 1,3-dibromopropenes can be prepared by isomerizing the corresponding 3,3-dihalopropene or homolog thereof in a simple, high yield process by contacting the latter with an effective silica, alumina, or zeolite catalyst. Thus, a mixture of cis- and trans-1,3-dichloropropenes is produced in good yield and with good selectivity when a mixture of 3,3-dichloropropene with other chlorinated hydrocarbons, principally 1,2-dichloropropane, is contacted with an acidic activated alumina catalyst at a temperature of about 100.degree. C.
Claims17
A process for preparing a dihaloalkene compound of the formula ##STR4## wherein X represents chloro or bromo and
- R.sup.1, R.sup.2, R.sup.3, and R.sup.4 independently represent hydrogen or a C.sub.1 -C.sub.3 alkyl group, with the proviso that when X represents bromo each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 represents hydrogen
- or a mixture thereof, which process comprises contacting a dihaloalkene compound of the formula ##STR5## wherein X represents chloro or bromo and
- R.sup.1, R.sup.2, R.sup.3, and R.sup.4 independently represent hydrogen or a C.sub.1 -C.sub.3 alkyl group, with the proviso that when X represents bromo each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 represents hydrogen in the liquid state with an effective catalyst selected from the group consisting of an alumina, a silica, and a zeolite at an effective temperature of from about 0.degree. C. to about 130.degree. C.
Dependencies are inferred from the claim text.