ethyl 3-(2-indol-1-ylethyl)-2-oxopiperidine-3-carboxylate

(3E)-3-[(4-Methyl-2-nitrophenyl)hydrazono]-2-piperidinone

5,8-dichloro-2,3,4,9-tetrahydropyrido[3,4-b]indol-1-one

3-(2-aminoethyl)-1H-indole-2-carboxylic acid