Acetic Anhydride → 2-Bromo-4-formamidothiazole

Participants

Reaction Conditions

Reaction Steps

Acetic anhydride (100 ml.) was cooled to 0° C. and treated with 98% formic acid (50 ml.). The resulting mixture was heated at 50° C. for 15 minutes then cooled to 0° C. To this solution of formic-acetic anhydride was added 4-amino-2-bromothiazole hydrobromide (26 g, 0.1 m) followed dropwise by pyridine (25 ml.). The reaction mixture was allowed to stand for 1 hour at room temperature then poured onto 20% aqueous sodium acetate solution (500 ml.). The resulting cyrstals were removed by filtration, washed once with water (100 ml.) then recrystallised from ethanol to give the 2-bromo-4-formamidothiazole (12 g, 58%). m.p. 167° C. d. (Found: C, 23.55; H, 1.6; N, 13.45. C4H3N2BrOS requires C, 23.2; H, 1.45; N, 13.5%).

Provenance & Evidence