Synonyms: 2-[3-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)prop-1-enyl]-1,3,3-trimethyl-3H-indolium acetate;3H-Indolium, 2-3-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)-1-propenyl-1,3,3-trimethyl-, acetate;3H-Indolium, 1,3,3-trimethyl-2-(3-(1,3,3-trimethyl-2-indolinylidene)pr openyl)-, acetate;C.I. Basic Red 12, acetate