Question

What are germinal dihalide ? And how they prepare?

Answer 1

Treatment of a geminal dihalide (both halogens on the same carbon) or a vicinal dihalide (halogens on adjacent carbons) with a base such as sodium ethoxide (NaOCH2CH3) yields a vinylic halide.


Chemical equation.

The vinylic halide prepared in greatest amount as an industrial chemical is vinyl chloride (CH2=CHCl). It is prepared from 1,2-dichloroethane (ClCH2CH2Cl).
Addition of a hydrogen halide to an alkyne
When a hydrogen halide adds to the carbon-carbon triple bond of an alkyne, addition of the first molecule is faster than the second, and a vinylic halide can be isolated.