1-Pentyne

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1-Pentyne, also known as propylacetylene, is an organic compound with the chemical formula C5H8. It is a member of the alkyne family, characterized by the presence of a carbon-carbon triple bond.

Structure and Properties

1-Pentyne is a linear alkyne with the molecular structure HC≡C-CH2-CH2-CH3. It is a colorless liquid at room temperature with a density of 0.691 g/cm³. The compound has a melting point of -106°C and a boiling point of 40-42°C.

Synthesis

1-Pentyne can be synthesized through various methods, including the dehydrohalogenation of 1-bromo-2-pentene or by the alkylation of acetylene with propyl bromide in the presence of a strong base.

Reactions

As an alkyne, 1-pentyne undergoes typical reactions associated with triple bonds. These include:

• Hydrogenation to form pentane.
• Hydrohalogenation to form 2-bromo-1-pentene.
• Hydration to form pentan-2-one.

Applications

1-Pentyne is used in organic synthesis and as an intermediate in the production of various chemicals. It is also used in the study of reaction mechanisms involving alkynes.

Safety

1-Pentyne is highly flammable and should be handled with care. It has a flash point of -30°C and an autoignition temperature of 470°C. Proper safety measures should be taken to avoid inhalation, ingestion, or skin contact.

See also

• 2-Pentyne
• Alkyne
• Organic chemistry