Reactions of o-phenylenediamine with 2-propynyl bromide and 1-bromo-2,4-undecadiyne in a nonpolar solvent lead to formation of the corresponding N-monoalkynylated products. Increase in the solvent polarity favors alkynylation at the second amino group to give symmetric N,N′-disubstituted product. Synthesis of amphiphilic diacetylenic o-phenylenediamine derivatives by reaction with 1-bromo-2,4-undecadiyne provides better yields of the N-alkynylated products than the Cadiot-Chodkiewicz method. A series of new acetylenic and diacetylenic derivatives of o-phenylenediamine was thus isolated and characterized.