反应详情

A solution of methyl acetoacetate (6.73 g, 58 mmol), 1-methylethyl 3-aminocrotonate (52) (8.34 g, 58 mmol) and 3-nitro-benzaldehyde (8.75 g, 58 mmol) in 2-propanol (80 mL0 was refluxed for 9 h. The mixture was diluted with dichloromethane (300 mL0 and dried (MgSo4), and the solvent was removed with a rotary evaporator. The crude product was recrystallized from ethyl acetate/hexane to afford 13.5 g (36 mmol, 62%) of 81 as a yellow crystalline solid: mp 142°-144° C. (lit.81 mp 147° C.); IR (CH2Cl2) 3440, 2960, 1695, 1622, 1530, 1470, 1352, 1215, 1100 cm-1 ; 1H NMR (CDCl3) δ 1.10 (d, J=6.2 Hz, 3H), 1.25 (d, J=6.2 Hz, 3H), 2.33 (s, 6H), 3.64 (s, 3 H), 4.95 (septet, J=6.2 Hz, 1H), 5.07 (s, 1H) 6.30 (s, 1H), 7.34-8.12 (m, 4H); 13C NMR (CDCl3) δ 19.95, 20.04, 22.35, 22.68, 40.53, 51.67. 67.98, 103.48, 104.19, 121.89, 123.61, 129.23, 135.07, 145.38, 145.91, 148.81, 150.61, 167.29, 168.35.

1. customdried (MgSo4)
2. customthe solvent was removed with a rotary evaporator
3. customThe crude product was recrystallized from ethyl acetate/hexane