Reagent used to convert 2-butyne from 1-butyne:

To convert 1-butyne into 2-butyne, a reagent known as sodium amide (NaNH2) is commonly used. This conversion involves a process called dehydrohalogenation, where a hydrogen halide (HX) is eliminated from a compound.

Here is a detailed explanation of the conversion process:

1. Dehydrohalogenation Process:
- The dehydrohalogenation process involves the removal of a hydrogen halide (HX) from a compound, resulting in the formation of an alkyne.
- In this case, 1-butyne is converted into 2-butyne by removing a hydrogen halide molecule.

2. Sodium Amide (NaNH2) as a Reagent:
- Sodium amide (NaNH2) is a strong base commonly used in organic chemistry reactions.
- It is often employed in dehydrohalogenation reactions due to its ability to abstract a hydrogen atom from a compound, leading to the formation of an alkyne.

3. Reaction Mechanism:
- The reaction between 1-butyne and sodium amide occurs in two steps.
- In the first step, NaNH2 abstracts a hydrogen atom from the terminal carbon of 1-butyne, forming a sodium acetylide intermediate.
- In the second step, the sodium acetylide intermediate reacts with another molecule of 1-butyne, resulting in the elimination of a hydrogen halide (HX) and the formation of 2-butyne.

4. Overall Reaction:
- The overall reaction can be represented as follows:
2 CH3-CH≡C-H + 2 NaNH2 → CH3-CH≡C-Na+ + 2 NH3 + H2 + 2 X

In summary, sodium amide (NaNH2) is used as a reagent to convert 1-butyne into 2-butyne through a dehydrohalogenation process. NaNH2 acts as a strong base, abstracting a hydrogen atom from 1-butyne and forming a sodium acetylide intermediate. The intermediate then reacts with another molecule of 1-butyne, resulting in the formation of 2-butyne while eliminating a hydrogen halide (HX).