General procedure for the synthesis of 5,8-dibromoimidazo[1,2-a]pyrazines from 2,5-dibromo-3-aminopyrazines and bromoacetaldehyde diethyl acetal: 3,6-dibromopyrazin-2-ylamine (4.0 g, 15.80 mmol) and bromoacetaldehyde diethyl acetal (3.7 mL, 24.00 mmol) were dissolved in a mixture of tetrahydrofuran (5.3 mL) and distilled water (53 mL ) in a solvent mixture. The reaction mixture was stirred at 120 °C for 4 hours. Upon completion of the reaction, the reaction solution was neutralized by addition of saturated aqueous sodium bicarbonate. The resulting solid was collected by filtration, washed with distilled water and dried to give 5,8-dibromoimidazo[1,2-a]pyrazine (2.75 g).