1H-Indole, 4-(1-ethyl-3-piperidinyl)-, (E)-2-butenedioate (2:1) 4-(1-Ethyl-3-piperidinyl)-1H-indole (E)-2-butenedioate (2:1) 4-(1-Ethyl-3-piperidyl)-1H-indole fumarate (2:1) 82439-15-4