An orally active Ras inhibitor with selectivity for H-Ras (Ki = 46 μM); inhibits both anchorage-dependent and -independent growth and induces apoptosis of H-RasG12V-transformed NIH 3T3 cells (IC50 = ~1.5 μM); exhibits antitumor activity in mice bearing a xenograft of human colon cancer SW480 cells expressing K-RasG12V at an oral dose of 80 mg/kg.