Pyridine → 2-Bromo-4-chloroacetamidothiazole

Beteiligte Stoffe

Reaktionsschritte

The starting material was prepared as follows. 4-Amino-2-bromothiazole (15.6 g) and chloroacetyl chloride (7.6 g) were suspended in methylene chloride (100 ml) with stirring and treated with pyridine (16 ml) over 15 min., maintaining reaction temperature at 0° C. with an ice bath. After the addition was complete, the reaction mixture was stirred at room temperature for 3 hours, then poured onto 20% aqueous sodium acetate (500 ml) and stirred for 30 minutes. The mixture was separated and the organic layer washed with 2 N hydrochloric acid, water, sodium carbonate solution and water. The organic layer was dried (MgSO4) and the solvent removed in vacuo and the residue recrystallised twice from carbon tetrachloride to give 2-bromo-4-chloroacetamidothiazole (5.1 g). m.p. 146°-8° C. (Found: C, 24.1; H, 1.7; N, 11.2. C5H4ClBrN2OS requires C, 23.5; H, 1.6; N, 11.0%).

Herkunft & Nachweise