Synthesis and pharmacological properties of benzothiazole, 1,3,4-oxadiazole and 1,3,4-thiadiazole derivatives

The reaction of the 2-amino-substituted 1,3,4-oxadiazoles 9,10 and the benzothiazoles 11,12 with ethyl cyanoacetate is described. The obtained cyanoacetamide derivatives 13-16 gave the benzylidene derivatives 18-21 by condensation with benzaldehyde. 2-Phenyl-5-amino-1,3,4-oxadiazolo[3,2-a]pyrimidin-7-one (17) was also obtained. Moreover, the preparation of 6,7,8,9-tetrahydro-5 H-1,3,4-thiadiazolo[2,3-b]quinazolin-5-thio-derivatives 22-25 and N-(1,3,4-thiadiazol-2-yl-5-substituted)-3,4-5,6-tetrahydro-ant hranilic acids 26-29 is also described. All above compounds and compounds, related to them, 1-8 were tested for their analgesic and antiinflammatory activities and the pharmacological screening results are reported and discussed