Acetamidine monohydrochloride → 5-Bromo-2-methylpyrimidine-4-carboxylic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of acetamidine hydrochloride (6.0 g) in ethanol (20 mL) was added sodium ethoxide (20 mL of a 21% solution in ethanol) and the reaction mixture was heated at 50° C. and mucobromic acid (6.82 g) in ethanol (10 mL) was added. After stirring at 50° C. for 1 h, a further portion of sodium ethoxide (10 mL of a 21% solution in ethanol) was added and the mixture was stirred at room temperature for 16 h. The mixture was then filtered and the filtrate reduced in vacuo. The residue was then treated with 2 M aqueous hydrochloric acid (30 mL) and stirred vigorously for 30 minutes. The resulting solid was filtered, washed with water and air dried to give 5-bromo-2-methyl-pyrimidine-4-carboxylic acid (1.46 g). This was then heated at 175° C. for 16 h. After cooling to room temperature the mixture was purified by Kugelrohr distillation to give 5-bromo-2-methyl-pyrimidine as a white solid (746 mg).

Herkunft & Nachweise