Acetic Anhydride → N-(6-bromo-1,3-benzothiazol-2-yl)acetamide

Participants

Reaction Steps

6-Bromobenzo[d]thiazol-2-amine (Aldrich, St. Louis, Mo.; 10.02 g, 43.7 mmol) was suspended in DCM (175 mL) to which DMAP (6.107 g, 50.0 mmol) was added. The flask was cooled in an ice water bath under argon, and acetic anhydride (4.60 mL, 48.8 mmol) was added, and the reaction was warmed to RT and stirred overnight. The reaction was washed with 10% HCl and water. The precipitate in the organic phase was filtered. The aqueous washings were extracted with DCM and 10:1 DCM/MeOH. These extracts were concentrated, combined with the filtrate from the above filtration, and concentrated again. The solid was collected (from the filtration as well as the aqueous workup), concentrated, and dried under vacuum to afford the desired N-(6-bromobenzo[d]thiazol-2-yl)acetamide (12.30 g, 45.39 mmol, 88% purity, 91% yield). MS (ESI pos. ion) m/z: 271 (MH+, 79Br), 273 (MH+, 81Br). Calculated exact mass for C9H7BrN2OS: 270 (79Br), 272 (81Br).

Provenance & Evidence