1: 3,4-diamino-5-bromopyridine; orthoformic acid triethyl ester With camphor-10-sulfonic acid 2 h; Reflux; 2: zink cyanide With tetrakis(triphenylphosphine) palladium(0) in N,N-dimethyl-formamide T=100°C; 2 h; Microwave irradiationInert atmosphere; Overall yield = 1.5 g;