page_title: Cyclopropylacetylene
section_title: Synthesis
hierarchical_section_title: Cyclopropylacetylene / Synthesis
caption_attribution_description: Nederlands: Cyclopropylacetyleen synthese
context_page_description: Cyclopropylacetylene is an hydrocarbon with the chemical formula C
  ₅H
  ₆. Under normal conditions, the substance is a colorless liquid. Cyclopropylacetylene is a precursor pharmaceuticals and other organic compounds.
context_section_description: Several methods have been published on the synthesis of cyclopropylacetylene. The earliest preparation starts with the chlorination of cyclopropylmethylketone with phosphorus pentachloride. Thereafter, the reaction product, 1-cyclopropyl-1,1-dichloroethane, is converted into cyclopropylacetylene via double dehydrochlorination. This occurs in presence of a strongly basic solution, such as potassium tert-butoxide in dimethyl sulfoxide:
  However, the yield of this method is not substantial (20-25%). A one-pot synthesis of cyclopropylacetylene has been reported in which 5-chloro-1-pentyne reacts with n-butyl lithium or n-hexyl lithium. Cyclohexane is used as a solvent. The reaction is a metalation followed by a cyclization. The reaction product is then cooled, and an aqueous solution of ammonium chloride is added slowly. There is a two-phase mixture: a heavy water phase and a lighter organic phase containing cyclopropylacetylene.
caption: Synthesis scheme 1
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