Used primarily in pharmaceutical research as a key intermediate in the synthesis of tricyclic antidepressants, particularly analogs of amitriptyline and imipramine. Its structure supports the development of compounds with modulatory effects on neurotransmitter reuptake, especially serotonin and norepinephrine. Due to the presence of both amino and carboxylic acid functional groups, it serves as a versatile building block for creating bioactive molecules with enhanced blood-brain barrier penetration. Also employed in the preparation of labeled derivatives for metabolic and receptor binding studies.