反应详情

A suspension of 4-fluorobenzamide (12.9 g) and ethyl 4-bromo-3-oxopentanoate (Chem Abs No. 36187-69-6; 5.24 g) in anhydrous toluene (120 ml) was heated at 140° C. for 19 h, using a Dean-Stark trap. The solution was allowed to cool, filtered, and the residual solid washed with toluene (30 ml). The combined filtrate and washings were concentrated in vacuo to give a brown oil, which was purified by Biotage flash chromatography on silica gel (90 g column), eluting with ethyl acetate:cyclohexane (5:95, 7.5:92.5, 10:90), to give thetitle compound as a yellow solid (2.98 g).

1. temperatureto cool
2. filtrationfiltered
3. washthe residual solid washed with toluene (30 ml)
4. concentrationThe combined filtrate and washings were concentrated in vacuo
5. customto give a brown oil, which
6. customwas purified by Biotage flash chromatography on silica gel (90 g column)
7. washeluting with ethyl acetate:cyclohexane (5:95, 7.5:92.5, 10:90)