Write the preparation of dehydrohalogenation vicinal and geminal dihalides
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the preparation of dehydrohalogenation vicinal and geminal dihalides
In organohalogen compound: Dehydrohalogenation of a dihalide. 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.
industrial process for the manufacture of acetylene. However, the method has now been replaced by a process in which methane is pyrolyzed in a flow system with short contact time.

This reaction is endothermic at ordinary temperatures, but is thermodynamically favored at high temperatures.
Laboratory Methods of Preparation of Alkynes:
1. Dehydrohalogenation of vic-Dihalides or gem-Dihalides

2. Dehalogenation of vic-Tetrahalogen Compounds

This reaction has the drawback that the halogen compound is itself prepared by halogen addition to alkynes.
3. Alkyl Substitution in Acetylene; Acidity of 

There is a fair amount of variety possible using this method. Acetylene itself may be alkylated either once to make a terminal alkyne or twice to make an internal alkyne.

Since acetylide ions are highly basic, competing elimination is a common side reaction.
The products of such an elimination reaction are an alkene (from the alkyl halide) and an alkyne.
In organohalogen compound: Dehydrohalogenation of a dihalide. 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.
industrial process for the manufacture of acetylene. However, the method has now been replaced by a process in which methane is pyrolyzed in a flow system with short contact time.

This reaction is endothermic at ordinary temperatures, but is thermodynamically favored at high temperatures.
Laboratory Methods of Preparation of Alkynes:
1. Dehydrohalogenation of vic-Dihalides or gem-Dihalides

2. Dehalogenation of vic-Tetrahalogen Compounds

This reaction has the drawback that the halogen compound is itself prepared by halogen addition to alkynes.
3. Alkyl Substitution in Acetylene; Acidity of 

There is a fair amount of variety possible using this method. Acetylene itself may be alkylated either once to make a terminal alkyne or twice to make an internal alkyne.

Since acetylide ions are highly basic, competing elimination is a common side reaction.
The products of such an elimination reaction are an alkene (from the alkyl halide) and an alkyne.
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