1-(2,2-Diethoxyethoxy)-4-fluorobenzene → 5-Fluoro-1-benzofuran

Participants

Reaction Steps

To a mixture of benzene (200 mL) containing polyphosphoric acid (80 g, 236.69 mmol) was added 2-(4-fluoro-phenoxy)-acetaldehyde diethyl acetal (45 g, 197.37 mmol). The mixture was stirred vigorously while being heated to reflux for 2.5 hours. The reaction mixture was cooled to room temperature and decanted from the polyphosphoric acid. The solvent was removed under vacuum to give the residue, which was purified by a silica gel column (1% ethyl acetate in petroleum ether) to afford 5-fluorobenzofuran as colorless oil (14.0 g, crude).

Provenance & Evidence