1,2-Dibromoethane → 3-(5-Chloro-2-thienyl)-5,6-dihydro-1,4,2-oxathiazine

Participants

Reaction Conditions

Reaction Steps

Methyl 5-chloro-2-thiophenecarbodithioate (61.4 g, 0.29 mol) was suspended in methanol (400 ml) with finely powdered hydroxylamine hydrochloride (25 g). With stirring, triethylamine (50 ml) in methanol (50 ml) was added dropwise to the suspension, to produce a reaction mixture. During this addition, the reaction mixture was cooled to 5° C. Stirring of the reaction mixture was continued until an orange (from red) color developed in the reaction mixture. Additional triethylamine (100 ml) was then added at once, followed by 1,2-dibromoethane (20 ml). The resultant reaction mixture was then stirred overnight at ambient temperature. The reaction mixture was then refluxed with removal of solvent until a precipitate appeared. The reaction mixture was then cooled and water was added. The reaction mixture was then filtered and the solid collected on the filter was recrystallized from ethanol to produce 3-(5-chloro-2-thienyl)-5,6-dihydro-1,4,2-oxathiazine (mp 74°-77° C., 21.4 g. Found C 38.5, H 2.94, N 6.45, C7 H6CINOS2 requires C 38.27, H 2.73, N 6.38).

Provenance & Evidence