Thionyl Chloride → 2-(Chloromethyl)-2H-1,4-benzothiazin-3(4H)-one

Participants

Reaction Steps

To a solution of 1.0 g of 2-hydroxymethyl-2H-1,4-benzothiazin-3(4H)-one in 20 ml of chloroform was added 0.9 ml of thionyl chloride, and the mixture was heated for 2 hours under reflux. The mixture was concentrated under reduced pressure and the residue was extracted with ether. The extract was washed with water, dried (MgSO4), and concentrated. The crude product was subjected to a column chromatography on silica-gel (40 g). From the eluate with hexane-ethyl acetate (4:1, v/v) was obtained 640 mg (58.7%) of 2-chloromethyl-2H-1,4-benzothiazin-3(4H)-one as crystals. Recrystallization from ethyl acetate and n-hexane gave needles, m.p. 152°-153° C.

Provenance & Evidence