p-Toluenesulfonic acid monohydrate → 2-Fluorodibenzo[B,F][1,4]thiazepin-11(10H)-one

Participants

Reaction Steps

A suspension of 2-(2-aminophenylthio)-5-fluorobenzoic acid (64.57 mmol, 17.51 g) in 500 mL xylenes was treated with p-toluenesulfonic acid monohydrate (64.57 mmol, 12.2 g) and heated. Additional 200 mL xylene was added and heating was continued with azeotropic removal of water for 16 h. The resulting pink reaction mixture was cooled to the room temperature and added to 300 mL water. After stirring for 15 min the solid removed by filtration, washed with 3×100 mL water and dried in air for 4 h, and then under high vacuum for 20 h to obtain 2-fluorodibenzo[b,f][1,4]thiazepin-11(10H)-one as a off white solid (11.6 g, 73%); MS (M+1) 246; 1H NMR (300 MHz, DMSO-d6) δ ppm 7.16 (t, 1H) 7.24 (d, J=7.2 Hz, 1H) 7.29-7.42 (m, 2H) 7.47 (dd, J=9.3, 2.9 Hz, 1H) 7.52-7.71 (m, 2H) 10.47-11.20 (m, 1H), MS 081119 M+1 246 (0.72).

Provenance & Evidence