To a stirred solution of N4-(3-chloro-4-fluorophenyl)-7-methoxy-4,6-quinazolinediamine (8) (4.0 g, 12.5 mmol) in dry tetrahydrofuran (150 mL) under nitrogen was added triethylamine (19 mmol), followed by freshly prepared (2E)-4-bromo-2-butenoyl chloride (15 mmol) in dry tetrahydrofuran (50 mL). The resulting solution was then stirred at room temperature for 2 hours and concentrated under reduced pressure. Trituration from dichloromethane gave crude (2E)-4-bromo-N-[4-(3-chloro-4-fluoroanilino)-7-methoxy-6-quinazolinyl]-2-butenamide (4.6 g) that was used directly.
