反应详情

1,3-Dihydro-4-fluoro-5-nitro-2H-indol-2-one (5.25 g, 26.8 mmol) (Starting Material 9) was suspended in 110 mL solution of 1.35% piperidine in 2-propanol (Aldrich). 3-Methoxy-2-pyrrolecarboxaldehyde (3.68 g, 29.4 mmol, 1.1 eq.)(Bellamy, supra) was added and this mixture heated at 60° C. for 3.5 hours (TLC: 50% ethyl acetate in hexanes). The reaction mixture was poured into 1 L ice and water mixture and the solid precipitate filtered, washed with water and dried at 50° C. under high vacuum to give (Z)-1,3-dihydro-4-fluoro-3-[(3-methoxy-1H-pyrrol-2-yl)methylene]-5-nitro-2H-indol-2-one as an orange-brown solid. (Yield 6.6 g, 81%).

1. filtrationthe solid precipitate filtered
2. washwashed with water
3. customdried at 50° C. under high vacuum