A mixture of 3-dimethylamino-1-(2-chloro-4-pyridyl)-2-propen-1-one (1.72 g, 8.18 mmol), 3-ethoxycarbonyl-phenyl-guanidine nitrite (2.21 g, 8.18 mmol), sodium hydroxide (0.327 g, 8.18 mmol) in 2-butanol (40 mL) is heated to reflux for 24 hours before cooling to room temperature with the addition of water (40 mL). The solid is collected by filtration, washed with water and 2-propanol, and dried to give N-[3-ethoxycarbonyl-phenyl]-4-(2-chloro-4-pyridyl)-2-pyrimidineamine (2.06 g); ESI-MS (m/z): 355.1 (M++H).
