Reactant for preparation of: . Indole derivatives as antitumor agents . Endothelin-1 antagonists . Oncrasin-1 derivatives as inhibitors of the C-terminal domain of RNA polymerase II with antitumor activities . Inhibitors of hepatitis C NS3/4A serine protease . Antibacterial agens against MDR Staphylococcus aureus strains . Antimalarial agents . Anti-bovine viral diarrhea virus (BVDV) agents . HIV-1 integrase inhibitors . Inhibitors of NF-κB transcription regulation related to TNF-α cytokine release Reactant for preparation of: . Indole derivatives as antitumor agents . Endothelin-1 antagonists . Oncrasin-1 derivatives as inhibitors of the C-terminal domain of RNA polymerase II with antitumor activities . Inhibitors of hepatitis C NS3/4A serine protease . Antibacterial agens against MDR Staphylococcus aureus strains . Antimalarial agents . Anti-bovine viral diarrhea virus (BVDV) agents . HIV-1 integrase inhibitors . Inhibitors of NF-κB transcription regulation related to TNF-α cytokine release