Acetic Acid → 9-methoxy-1-oxo-3,4-dihydro-2H-benzothiopheno[2,3-f][1,4]thiazepin-5-one

Participants

Reaction Steps

A mixture of 2,3 -dihydro-9 -methoxy-[1]benzothieno [2,3-f]-1,4-thiazepin-5 (4H) -one (200 mg, 0.75 mmol) and NaBO3 -4H2O (116 mg, 0.75 mmol) in 18 mL of AcOH is stirred at room temperature overnight. The reaction mixture is filtered and 60 mL of water is added to the filtrate. Filtration provides 2,3-dihydro-9-methoxy-[1]benzothieno[2,3-f]-1,4-thiazepin-5 (4H) -one-1-oxide in 69% yield, mp 215°-216° C. (dec).

Provenance & Evidence