Question

Which of the following is Vinyl halide?
A.\[ClC{H_2}-{\text{ }}C{H_2}Cl\]
B.\[C{H_2}C{l_2}\]
C.\[C{H_2} = CH{\text{ }} - {\text{ }}Cl\]
D.${\text{CH}} \equiv {\text{C - Cl}}$

Answer 1

Hint: We must know that the vinyl halide contains a halide group in it along with any alkenyl group. The word vinyl represents an alkenyl chain of carbon atoms.

Complete step by step answer:
Let’s start with discussing some basic information regarding the Vinyl Halide. As the name suggests vinyl halide contains a halide group in it along with any alkenyl group. The word vinyl represents an alkenyl chain of carbon atoms. The vinyl halide is usually synthesized using the dehydrochlorination of 1, 2-dichloroethane. Dehydrochlorination means the removal of hydrogen and chlorine from the molecule.
So, when we perform dehydrochlorination of 1,2-dichloroethane, we get the following reaction
\[Cl - C{H_2}{\text{ }} - {\text{ }}C{H_2} - Cl{\text{ }} \to {\text{ }}C{H_2}{\text{ }} = {\text{ }}CHCl{\text{ }} + {\text{ }}HCl\]
So, the vinyl halide is having the formula\[C{H_2} = CH{\text{ }} - {\text{ }}Cl\].
Hence, the answer to this question is C. i.e \[C{H_2} = CH{\text{ }} - {\text{ }}Cl\].

Additional information:
The halogen atom attached directly to the carbon atom of the carbon-carbon unsaturated bond is much less reactive than the normal alkyl halide. Specifically, aryl and vinyl halides undergo displacement reactions (with hydroxide, alkoxide) only under such strict conditions that these reactions are rarely attempted in the laboratory.
The elimination reactions of vinyl halides are less difficult and the conversion of vinyl bromide to acetylene by heating with a base. If the aromatic halide is allowed to react with a strong base, such as sodium amide\[\left( {NaN{H_2}} \right)\], elimination also occurs. The resulting intermediate is called benzine and is highly strained. Benzynes could not be isolated, since they react easily with either excess amide or with themselves to give dimers.

Note:
We can use vinyl halide generally as reagents in many reactions like in the preparation of Grignard reagent. Also the vinyl halides undergo base elimination and produce the respective alkynes. Also we can use it in cross coupling reactions like Stille coupling, Heck coupling, etc.