3-(4-Fluorophenoxy)propionic acid → 6-fluoro-2,3-dihydro-4H-1-benzopyran-4-one

Participants

Reaction Steps

A mixture of 30.0 g (163.0 mmol) of 3-(4-fluorophenoxy)propionic acid and 180 ml of concentrated sulfuric acid was stirred for 1 hour at room temperature and then the reaction mixture was poured into 700 g of ice to deposit immediately a white crystal. The white crystal was collected by filtration, washed with water and dried in air, and the resultant was recrystallized from ethanol to give 20.55 g of 6-fluoro-4-chromanone as a white crystal (yield: 76%).

Provenance & Evidence