1-(Phenylmethyl)-2-[(triphenylphosphoranylidene)amino]-1H-indole-3-carboxaldehyde is an intermediate in synthesizing 2,3,4,10-Tetrahydro-1H-indolo[2,3-b][1,8]naphthyridin-2-ol (T294270), a derivative of 6,7,8,9-Tetrahydro-7-hydroxy-5-methyl-3-phenyl-pyrido[3’,2’:4,5]imidazo[1,2-a]pyrimidinium Chloride (H957770), a carcinogen used in the study of intestinal bacteria metabolism. Created through the heat processing of food.