反应详情

温度

60 °C

To a solution ethyl 3-(3-methoxy-2-methylphenyl)-3-oxopropanoate (137.2 g, 595 mmol, from Step A) in ethyl alcohol (924 mL), 10% Pd—C (13.7 g) was added and 3 atm of hydrogen were applied. The mixture was heated to 60° C. for 20 hr, cooled to ambient temperature and filtered through Celite®. The filtrate was concentrated in vacuo and the residue purified by flash chromatography (2% EtOAc/hexanes) on SiO2 to afford 110.8 g of the title compound as a pale yellow liquid: 1H NMR (500 MHZ, CDCl3) δ 1.25 (t, 3H, J=7.1 Hz), 2.19 (s, 3H), 2.55 (t, 2H, J=8.0 Hz), 2.95 (t, 2H, J=8.0 Hz), 3.82 (s, 3H), 4.14 (q, 2H, J=7.1 Hz), 6.73 (d, 1H, J=8.2 Hz), 6.78 (d, 1H, J=7.6 Hz), 7.10 (d, 1H, J=7.9 Hz).

1. temperaturecooled to ambient temperature
2. filtrationfiltered through Celite®
3. concentrationThe filtrate was concentrated in vacuo
4. customthe residue purified by flash chromatography (2% EtOAc/hexanes) on SiO2