反应详情

A suspension of 8.5 g (40.0 mmol) of 4-(2-hydroxyethoxy)mandelic acid (compound (201), Example 10, Table 2) and 12.0 g (110 mmol) of p-cresol is maintained at 180° C. under a nitrogen atmosphere for 75 minutes, during which the water formed distils off. Excess p-cresol is then distilled off in a vacuum rotary evaporator. Chromatography of the residue on silica gel using the eluent system 9:1 dichloromethane/ethyl acetate gives 6.6 g (58%) of 3-[4-(2-hydroxyethoxy)phenyl]-5-methylbenzofuran-2-one, a yellowish resin (compound (119), Table 1).

1. customformed
2. customdistils off
3. distillationExcess p-cresol is then distilled off in a vacuum rotary evaporator