Abstract

Acetylene, C₂H₂, is an extremely reactive hydrocarbon, principally used as a chemical intermediate. Because of its relatively high price, there have been continuing successful efforts to replace acetylene with cheaper raw materials. The name ethynylation was coined by Reppe to describe the addition of acetylene to carbonyl compounds. Principal Reppe acetylene chemicals include propargyl alcohol, butynediol, butenediol, butanediol, and butyrolactone. Butynediol is principally consumed in manufacture of butenediol and butanediol. Butanediol is consumed in manufacture of butyrolactone and tetrahydrofuran. Large amounts are also used as a monomer for polyesters and polyurethanes. Butyrolactone is principally used as an intermediate for manufacture of pyrrolidones. Propargyl alcohol is a primary skin irritant and severe eye irritant, highly toxic by all means of ingestion. Catalytic vinylation, in which a labile hydrogen compound adds to acetylene, forming a double bond, has been applied to a wide range of alcohols, phenols, thiols, and carboxylic acids. Vinyl ethers are used in the manufacture of glutaraldehyde and as monomers.