p-Phenetidine Hydrochloride is primarily used as an intermediate in the synthesis of various dyes and pigments. It plays a crucial role in the production of azo dyes, which are widely applied in the textile industry for coloring fabrics. Additionally, it is utilized in the preparation of certain pharmaceuticals, particularly in the synthesis of compounds with analgesic and antipyretic properties. Its application extends to organic synthesis, where it serves as a building block for creating complex chemical structures in research and industrial processes.