Synthesis of some new pyrazole, 1,3-thiazoleand 1,3,4-thiadiazole derivatives incorporating 4-pyridyl moiety

Abstract

2-Cyano-N-(pyridin-4-yl)acetamide (2) was prepared andthen treated with hydrazonoyl chlorides 3 to afford the corresponding aminopyrazoles 5. Heating a mixture of 2 with benzylidenemalononitriles and with ethyl benzylidenecyanoacetates afforded the corresponding bipyridines  10 and 16, respectively. Treatment of 2 with phenylisothiocyanatein DMF/KOH followed by addition of the appropriate hydrazonoyl chlorides  5, 10 and ethyl chloroacetate gave the corresponding 1,2,4-thiadiazoles  22 and 27 and 1,3-thiazole 24, respectively.