Here we describe the synthesis, antioxidant and anti-inflammatory activity of the novel N3 substituted 5,7-dimethyl-6-phenylazo-3Н-thiazolo[4,5-b]pyridin-2-ones, who were synthesized in reactions aminomethylation, cyanoethylation, hydrolysis and under the reaction of nucleophilic substitution. The antioxidant activity of the synthesized compounds was evaluated in vitro by the method of scavenging effect on 2,2 diphenyl-1-picrylhydrazyl (DPPH) radicals. The anti-inflammatory action was evaluated in vivo employing the carrageenan-induced rat paw edema method.