|Jmol-3D images||Image 1|
|Molar mass||296.36 g mol−1|
|Melting point||280 °C; 536 °F; 553 K|
|Solubility in water||Insoluble|
|Solubility in ethanol, xylene||Soluble[vague]|
| (what is: / ?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Thioindigo is generated by the alkylation of the sulfur in thiosalicylic acid with chloroacetic acid. The resulting thioether cyclizes to 2-hydroxythianaphthene, which is easily converted to thioindigo. The related compound 4,7,4',7'-tetrachlorothioindigo, also a commercially important dye, can be prepared by chlorination of thioindigo.