Methanol → Methyl 4-(difluoromethoxy)-3-hydroxybenzoate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

100 g of 3-hydroxy-4-(difluoromethoxy)-benzaldehyde (0.53 mol) were dissolved in MeOH (600 ml), solid Oxone® (325 g, 1.06 mol) was added portion-wise in 1 hour and solution was stirred and warmed to 50-55° C. for 2 hours. The solvent was concentrated under vacuum to 200 ml and water (1 L) was added. The resulting heterogeneous solution was stirred at 50 to 55° C., then toluene (500 ml) was added, and the biphasic mixture vigorously stirred. Aqueous phase was discharged and the organic one was washed with water (500 ml). Active charcoal (10 g) was added and the organic solution stirred for 20 minutes. It was filtered on a celite pad, the solvent was concentrated under vacuum to 2 to 3 volumes, and the obtained solution was warmed to 80 to 90° C. n-Heptane (400 ml) was slowly added. The mixture was cooled to 0° C. and the suspension was stirred at 0° C. over-night. The solid was filtered on a Buchner funnel and washed with n-heptane (100 ml). The obtained white solid was dried under vacuum at room temperature. (yield 70%).

Herkunft & Nachweise