Starting from 2,3-diaminopyridine, several novel 2-amino [2,3:4,5] -6, 7-11, 13-16, 20 and 21 were screened in vitro for their antibacterial and antifungal activity by the agar diffusion method and most of them showed a pronounced anti-inhibitory effect. Compound 22a showed pronounced analgesic activity by i.p. injection of 0.5-1.0 mg/kg in conscious rats in a hot plate testing procedure.