Reactant for preparation of tryptophan dioxygenase inhibitors pyridyl-ethenyl-indoles as potential anticancer immunomodulators.and for synthesis of indolylindazoles and indolylpyrazolopyridines as interleukin-2 inducible T cell kinase inhibitors.and for preparation of diindolyloxyindoles as anticancer agents. Reactant for preparation of tryptophan dioxygenase inhibitors pyridyl-ethenyl-indoles as potential anticancer immunomodulators.and for synthesis of indolylindazoles and indolylpyrazolopyridines as interleukin-2 inducible T cell kinase inhibitors.and for preparation of diindolyloxyindoles as anticancer agents.