indophenin
noun
in·do·phe·nin
ˌindəˈfēnə̇n,
ə̇nˈdäfənə̇n
: a blue crystalline compound C24H14N2O2S2 formed by reaction of thiophene with isatin and sulfuric acid and used as a color test for the presence of thiophene in technical benzene
Word History
Etymology
International Scientific Vocabulary ind- entry 2 + phene + -in; from a belief that it was a derivative of benzene; originally formed in German