4-Aminothiophenol, also known by its CAS number 1193-02-8, is a fascinating organic compound with a distinct set of chemical properties that make it highly valuable in numerous industrial applications. This article aims to shed light on its physical and chemical characteristics, as well as its significant roles as an intermediate in the synthesis of pesticides, pharmaceuticals, and dyes.

Physically, 4-Aminothiophenol typically presents as an off-white to brown powder. It has a melting point range of 37-42 °C, indicating it is a solid at room temperature but can melt with moderate heating. The compound's molecular formula is C6H7NS, with a molecular weight of approximately 125.19 g/mol. Its density is estimated to be around 1.136 g/cm³. The compound's boiling point is recorded as 140-145 °C at 16 mm Hg, and it has a flash point greater than 230 °F, suggesting a relatively low flammability risk under normal handling conditions.


Chemically, 4-Aminothiophenol possesses both an amine group (-NH2) and a thiol group (-SH) attached to a benzene ring. This dual functionality is what lends it such versatility as a chemical intermediate. The amine group can readily undergo reactions such as acylation, alkylation, and diazotization, while the thiol group is susceptible to oxidation, alkylation, and addition reactions. These reactive sites allow it to be incorporated into a wide variety of more complex molecular structures.


The applications of 4-Aminothiophenol are diverse and impactful. As a pesticide intermediate, it is used in the synthesis of agrochemicals designed to protect crops, contributing to improved agricultural productivity. In the pharmaceutical sector, it serves as a crucial building block for synthesizing active pharmaceutical ingredients (APIs) and other medicinal compounds, aiding in the development of new treatments for various diseases. The dye industry also benefits from its reactive nature, using it to produce a spectrum of colorants for textiles and other materials.


Proper storage and handling are essential for maintaining the quality of 4-Aminothiophenol. It should be kept in a dry, clean warehouse with good ventilation, away from direct light and heat. Protection from leakage, rain, and insolation during transportation is also critical. By understanding these chemical properties and handling guidelines, manufacturers can effectively utilize 4-Aminothiophenol to produce high-quality end products and advance their respective industries. Its role as a reliable intermediate in pesticide, medicine, and dye synthesis solidifies its importance in the chemical landscape.