Methylacetylene (74-99-7)

 MEthyl acetylene (74-99-7) is a convenient three-carbon building block for organic synthesis. Deprotonation with n-butyllithium gives propynyllithium. This nucleophilic reagent adds to carbonyl groups, producing alcohols and esters.Whereas purified propyne is expensive, MAPP gas can be used to cheaply generate large amounts of the reagent.It exists in equilibrium with allene, the mixture of methylacetylene and propadiene being called MAPD.Research by European space concerns into using light hydrocarbons with liquid oxygen as a relatively high performing propellant combination which would also be less toxic than the commonly used MMH/NTO (monomethylhydrazine/nitrogen tetroxide) systems, showed that propyne would be highly advantageous as a rocket fuel for craft intended for low Earth orbital operations. This conclusion was reached based upon a specific impulse expected to reach 370 s if oxygen is used as oxidizer, a high density, and energy/volume ratio, and the moderate boiling point, which causes the chemical to present fewer problems in storage than for example a fuel that needs to be kept at extremely low temperatures.

Reported in EPA TSCA Inventory.