4,4'-(1,2-ethynediyl)bis(benzoic acid) dimethyl ester;

di(p-carbomethoxyphenyl)acetylene;

Dimethyl 4,4'-(ethyne-1,2-diyl)dibenzoate;

1,4-bis(p-carbomethoxybenzene)-1,2-acetylene;

1,2-bis(4-methoxycarbonylphenyl)acetylene;