Formation and Use of Acetylide Anion Nucleophiles

An acetylide anion is formed by reaction of a terminal alkyne with sodium amide, which is a very strong base. The acetylide anion can then perform nucleophilic substitution upon methyl and primary alkyl halides. (Being a strong base, acetylide anion would react by elimination with secondary and tertiary alkyl halides, rather than by nucleophilic substitution).