US 4,393,227 AGranted

Process for dechlorinating organic compounds

AssigneeE. I. Du Pont de Nemours and Company

InventorEdward N. Squire

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Abstract

Olefinic compounds are made from their vicinally chlorinated organic precursors by dechlorination with metallic magnesium in the presence of a mercury-based promoter, which may be a water-soluble mercury salt or metallic mercury, and of a catalytic amount of iodine. This process is particularly suitable for dechlorinating 4,5-dichloro-dioxolanes to the corresponding dioxoles. 4,5-Difluoro-2,2 bis(trifluoromethyl)-1,3-dioxole, which can be made by this process in a reproducible manner from 4,5-dichloro-4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxolane, is a useful monomer for making amorphous homopolymers and copolymers with tetrafluoroethylene, which are well suited for wire coating, finishes, and transparent glazing for corrosive service.

Claims18

Dependent claims

A process for dechlorinating an organic compound selected from the group consisting of ##STR4## where each of Y and Z independently is hydrogen, chlorine or fluorine, provided at least one of Y and Z is fluorine;

and each of R.sup.3 and R.sup.4 independently is hydrogen, fluorine or trifluoromethyl to the ethylenically unsaturated compound,
said process comprising contacting the organic chlorine-containing compound with at least a stoichiometric amount of metallic magnesium, a mercury based promoter selected from water-soluble mercury salts and metallic mercury, and iodine in the presence of tetrahydrofuran at a temperature from about room temperature to at least the boiling point of tetrahydrofuran at the operating pressure;
with a proviso that magnesium amalgam can be used in lieu of magnesium and the mercury-based promoter.

Dependencies are inferred from the claim text.