7-Amino-6H-anthra[9,1-cd]isothiazol-6-one (CAS 6337-02-6) has a molecular formula of C??H?N?O S and a molecular weight of 264.30 g/mol, with an amino group (-NH?) attached to the fused anthracene-isothiazolone heterocyclic core. As a polycyclic aromatic heterocycle, it is a key intermediate in synthesizing functional dyes, pharmaceuticals, and optoelectronic materials, valued for its conjugated structure. It requires sealed, cool, dark storage to avoid oxidation or photodegradation, preserving reactivity for synthetic applications.