chromatography on silica hexanes etoac 5 1 to 3 1 as eluent to afford 6 8 dibromo 2 furan 2 yl 1 2 4 triazolo 1 5 a pyrazine as a yellow solid 19 2 g 40 yield 1 h nmr 300 mhz cdcl 3 u03b4 6 60 dd 1h 7 33 d 1h 7 62 d 1h 8 63 s 1h anhydrous ammonia was bubbled over a one hour period into a solution of 6 8 dibromo 2 furan 2 yl 1 2 4 triazolo 1 5 a pyrazine 18 4 g 0 054 mol in dioxane 400 ml the resulting mixture was stirred at room temperature for 2 days during which time the solution was twice recharged with ammonia by bubbling in for one hour after concentration diethyl ether 200 ml was added and the resulted yellow slurry was stirred at room temperature for overnight 6 bromo 2 furan 2 yl 1 2 4 triazolo 1 5 a pyrazin 8 ylamine was then collected and dried 15 g 99 yield 1 h nmr 300 mhz cdcl 3 u03b4 6 70 dd 1h 7 10 d 1h 7 8 8 0 br m 3h 8 58 s 1h ms m z 280 m h synthesis of the title compound is described in parts a c below a stirred solution of 3 5 dibromo pyrazin 2 ylamine 500 mg 1 98 mmol thiophene 2 carbonitrile 260 ul 2.