C18H12N2O2

C18H12N2O2 is the molecular formula for several organic compounds, most notably **anthranilic acid derivatives** and **indigoid pigments**. One of the most well-known compounds with this formula is **indigo**, a natural dye historically used for textiles. Indigo is a blue pigment derived from plants such as *Indigofera* species and has been utilized for centuries in dyeing fabrics, including traditional garments like denim.

Chemically, indigo is a heterocyclic compound belonging to the class of indigoids. Its structure consists of two fused benzene rings connected by a five-membered ring containing two nitrogen atoms and two carbonyl groups. This arrangement contributes to its vibrant blue color and stability. Indigo is insoluble in water but soluble in organic solvents like acetone and dimethylformamide.

Another compound with the same molecular formula is **isatin**, a white crystalline solid with the formula C18H12N2O2 when considering its dimer form. Isatin is a derivative of indoxyl and is primarily used in organic synthesis, particularly in the production of dyes and pharmaceuticals. It is also a key intermediate in the synthesis of various heterocyclic compounds.

Both indigo and isatin exhibit significant importance in industrial and historical contexts. Indigo, in particular, has played a crucial role in global trade and cultural practices, while isatin remains relevant in modern chemical research and manufacturing. The structural similarities between these compounds highlight the versatility of the C18H12N2O2 framework in organic chemistry.