Sulfuric Acid → 2-(bromomethyl)-7-(methylsulfonyl)-4H-1,3-benzodioxine

Participants

Reaction Steps

2-(hydroxymethyl)-5-(methylsulfonyl)phenol (3.3 g, 16.3 mmol), 2-bromo-1,1-dimethoxyethane (19.0 ml, 163 mmol), dry THF (30 ml) and concentrated H2SO4 (5 ml) were heated at 55° C. for 1 h. The reaction mixture was brought to ambient temperature and EtOAc and water were added. The phases were separated and the aqueous phase was extracted twice with EtOAc. The combined organic phases were dried (Na2SO4), filtered and evaporated to dryness to give an oil (9.0 g). The oil was crystallizing upon cooling. The product was washed with EtOAc, EtOH and DEE and afforded the pure title compound (4.0 g, 80%). MS m/z (rel. intensity, 70 eV) 308 (M+, 11), 306 (M+, 10), 213 (45), 184 (bp), 77 (35).

Provenance & Evidence