反应详情

A solution of the keto-ester (48)(20.00 g, 79.3 mmol) in acetic anhydride (80 mL) was added dropwise to a stirring solution of HNO3 (400 mL) and Ac2O (80 mL) at 0° C. After stirring for 2.5 hours the reaction mixture was poured into iced water (3 L) and allowed to stand at 4° C. for a further 16 hours. The precipitate was collected by filtration and dried under vacuum to provide the nitro compound (49) as a yellow crystalline solid (14.52 g, 62%). Melting Point 70-73° C. 1H NMR (250 MHz, CDCl3) δ 10.4 (s, 2H), 7.61 (s, 1H), 7.40 (s, 1H), 4.21 (t, J=6.2 Hz, 2H), 4.00 (s, 3H), 3.71 (s, 3H), 2.58 (t, J=7.1 Hz, 2H), 2.23 (pent, J=6.3 Hz, 2H). 13C NMR (67.8 MHz, CDCl3) 188.2 (C1), 173.7 (C12), 153.8 (Cquat.), 152.1 (Cquat.), 144.1 (Cquat.), 125.8 (Cquat.), 110.2 (C6), 108.5 (C3), 69.0 (C9), 57.0 (C8), 52.2 (C13), 30.6 (C11), 24.4 (C10). IR (cm−1) 3571, 3485, 2951, 1725, 1689, 1573, 1329, 1172, 1064, 1002, 936, 896, 858, 820, 766, 738, 688, 624. MS (M+1) 298.0. Anal. Calcd for C13H15NO7: C, 52.53; H, 5.09; N, 4.71. Found: C, 52.80; H, 5.03; N, 4.75.

1. waitto stand at 4° C. for a further 16 hours
2. filtrationThe precipitate was collected by filtration
3. customdried under vacuum