Trifluoroacetic anhydride → HCID 22394204, compound

Participants

Reaction Steps

3-Chlorobenzylmercaptoacetic acid from Step 2 (3.35 g) was dissolved in trifluoroacetic acid (50 mL). Trifluoroacetic acid anhydride (25 mL) was added and the reaction stirred at reflux, under a nitrogen atmosphere for 16 hours. The solution was carefully poured into 10% Na2CO3 solution (500 mL) which was stirring vigorously. The organics were extracted into ether (500 mL) and washed with brine (300 mL), dried over MgSO4 and concentrated in vacuo. The resulting brown solid was purified by silica gel chromatography eluting with a 0-10% gradient of ethyl acetate in hexane to yield 7-chloroisothiochroman-4-one (1.57 g, 51%): 1H NMR (CDCl3) δ=3.49p (d, 2H, J=0.8 Hz), 3.8p (s, 2H), 7.16p (m, 1H), 7.3p (dd, 1H, J=2.0, 8.4 Hz), 7.96p (d, 1H, J=8.5 Hz).

Provenance & Evidence