Synthesis of Some Pyrazole,Thiazole, Pyridine,and 1,3,4‐Thiadiazole Derivatives Incorporating 2‐Thiazolyl Moiety

Reaction of N‐(5‐acetyl‐4‐methylthiazol‐2‐yl)‐2‐cyanoacetamide 2 with hydrazonoyl chlorides ( 3a,b ) yielded the corresponding aminopyrazole derivatives ( 5a,b ), respectively. Reaction of 2 with α,β‐benzylidenemalononitrile derivatives 8a,b and 13a,b afforded the corresponding pyridine derivatives 12a,b and 17a,b , respectively. Treatment of 2 with phenylisothiocyanate in dimethylformamide/KOH followed by the addition of ethyl chloroacetate and the appropriate hydrazonoyl chlorides 3a,b and 27 gave the corresponding 1,3‐thiazole 21 and 1,2,4‐thiadiazole derivatives 24a,b and 30 , respectively. The newly synthesized compounds were confirmed from their elemental analyses and spectral data.