Methyl propiolate is an organic compound with the formula HC<sub>2</sub>CO<sub>2</sub>CH<sub>3</sub>. It is the methyl ester of propiolic acid, the simplest acetylenic carboxylic acid. It is a colorless liquid that is miscible with organic solvents. The compound is a reagent and building block for the synthesis of other organic compounds, reactions that exploit the electrophilicity of the alkyne group. For example it is a potent dienophile. It has been widely evaluated as a precursor to heterocycles. including 1,3-dipolar cycloadditions.