反应详情

3.00 g (roughly 65%, 6.56 mmol) of the above prepared [2-(3-methoxy-propyl)-4-nitro-phenoxy]-acetic acid ethyl ester was hydrogenated at RT in 50 ml of EtOAc over 0.60 g of Pd/C (10%) under 1 atm. of H2-pressure. After 3 h at ambient temperature, the reaction mixture was filtered over Celite and carefully rinsed with EtOAc. Evaporation of the solvent, followed by flash chromatography (SiO2, hexane/EtOAc=1/1) produced 1.69 g of the title compound as light brown oil; from the more polar fractions, 0.784 g of 8-(3-methoxy-propyl)-4H-benzo[1,4]oxazin-3-one was isolated (cyclized reduced ortho-amino derivative), MS: 268.3 (MH+)+; side product: 221.1 (M)+.

1. filtrationthe reaction mixture was filtered over Celite
2. washcarefully rinsed with EtOAc
3. customEvaporation of the solvent