Dechlorination of pyridines in acidic, zinc-containing mediums
AssigneeReilly Industries, Inc.
InventorsPhillip B. Lawin, Z. Jason Yang, L. Mark Huckstep
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Abstract
Described are preferred processes for preparing 3,5-dichloropyridines by dechlorinating higher-chlorinated pyridine compounds such as 2,3,5,6-tetrachloropyridine in an acidic medium in the presence of zinc and optionally a quaternary ammonium catalyst.
Claims22
A process for preparing 3,5-dichloropyridine, comprising:
- dechlorinating a tri-, tetra- or pentachloropyridine compound including chlorines at the 3- and 5-positions of the pyridine ring in an acidic reaction medium including zinc to selectively form a 3,5-dichloropyridine compound.
A process for producing 3,5-dichloropyridine, comprising dechlorinating a pyridine compound of the formula:
- wherein R1, R2, and R3, are H, chloro, or a C1 to C20 hydrocarbon group, with the proviso that at least one of R1, R2, and R3 is chloro, in the presence of zinc in an acidic reaction medium, to form a corresponding 3,5-dichloropyridine compound.
A process for selectively preparing 3,5-dichloropyridine, comprising dechlorinating 2,3,5,6,-tetrachloropyridine in acetic acid in the presence of zinc to selectively form 3,5-dichloropyridine.
Dependencies are inferred from the claim text.