Formamidine hydrochloride is widely used in the synthesis of pharmaceuticals, particularly in the production of antihistamines and other therapeutic agents. It serves as a key intermediate in the manufacture of drugs that target allergic reactions and respiratory conditions. In agriculture, it is utilized as a precursor for certain pesticides and herbicides, helping to protect crops from pests and weeds. Additionally, it finds application in organic chemistry as a reagent for the preparation of various heterocyclic compounds, which are important in the development of dyes, polymers, and other industrial chemicals. Its role in these processes highlights its versatility and importance in both the pharmaceutical and chemical industries.