Aluminum(III) Chloride → 4-Fluoro-1,3-benzothiazol-7-ol

Participants

Reaction Steps

To a solution of 4-fluoro-7-methoxy-1,3-benzothiazole (C13) (10.50 g, 57.30 mmol) in dichloromethane (250 mL) was added aluminum chloride (30.56 g, 229.2 mmol) in one portion at room temperature. The reaction mixture was stirred for 12 hours and additional aluminum chloride (30.56 g, 229.2 mmol) was added. After another 12 hours, the reaction mixture was poured into ice water (1.0 L). The resulting precipitate was collected by filtration, washed with water, and with 1:1 dichloromethane/hexanes to afford the title compound as a yellow solid. Yield: 6.60 g, 39.0 mmol, 68%. Melting point: 165-167° C. LCMS m/z 170.4 (M+1). 1H NMR (300 MHz, DMSO-d6) δ 6.82 (m, 1H), 7.21 (m, 1H), 9.37 (s, 1H), 10.57 (s, 1H).

Provenance & Evidence