Hydrochloric Acid → 4-(Oxazol-2-yl)phenol

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-(oxazol-2-yl)phenyl methanesulfonate (11.2 g, 46.81 mmol) in THF (200 mL), a freshly prepared aqueous solution of KOH (40 wt. %, 13.2 mL, 93.6 mmol, 2 equiv.) was added. The reaction mixture was stirred at 80° C. for 4 hours and at ambient temperature overnight. Another 2 equiv. of aqueous solution of KOH (40 wt. %, 13.2 mL, 93.6 mmol) was then added and the reaction mixture was continuously stirred at 80° C. for 3 hours. After cooling, the reaction mixture was cautiously brought to pH 5 with 1 M aqueous HCl. The mixture was extracted with ethyl acetate. The organic layer was washed with brine, dried over Na2SO4, and concentrated under reduced pressure. Flashmaster chromatography on 50 g of silica gel using a gradient of 100% CH2Cl2→90% CH2Cl2+10% methanol gave 4.25 g (56% th.; 38% pract.) of 4-(oxazol-2-yl)phenol; 1H NMR (CD3OD) δ 7.86 (d, 1H), 7.84 (d, 2H), 7.20 (d, 1H), 6.88 (d, 2H) ppm.

Provenance & Evidence