The present invention provides a novel process for selectively alkylating pyrazoles comprising reacting a 3(5)-cyano-1H-pyrazole-4-carboxylic acid ester with a C₄-C₁₁ alkene, or a C₅-C₆ cycloalkene, and a strong acid in a solvent which contains a strong electron withdrawing group. Also provided are new 3(5)-cyano-1H-pyrazole-4-carboxylic acid esters.