Corresponding 2, 3-dihydro-2-oxo-lH-indole-3-alkanoic acid esters. The monomeric thiones undergo facile and reversible oxidation to the corresponding 2, 2'-dithiobis (1H-indole-3- alkanoic acids). The compounds were evaluated for their abilities to inhibit the tyrosine kinase activity of the epidermal growth factor receptor using a native complex contained in plasma membrane vesicles shed from cultured A431 cells, and to inhibit the growth of ...