Trifluoroacetic acid → 1H-2,1-Benzothiazine 2,2-dioxide

Participants

Reaction Steps

The title compound was synthesized according to the method described in WO 2008/073956 A2. To a solution of 1-(4-methoxybenzyl)-1H-benzo[c][1,2]thiazine 2,2-dioxide (0.9 g, 3 mmol) in anhydrous methylene chloride was added trifluoroacetic acid (18 mL). The mixture was stirred at room temperature for 5 hours and then concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (25-70% ethyl acetate in hexanes) to give a white solid. (0.6 g, 72%). 1H NMR (CDCl3, 300 MHz) δ 7.43-7.38 (m, 2H), 7.29 (m, 1H), 7.20-7.14 (dt, 1H, J=1.2, 7.5 Hz), 7.02-6.99 (d, 1H, J=7.8 Hz), 6.78-6.75 (dd, 1H, J=2.4, 10.5 Hz).

Provenance & Evidence