New series of substituted thiazole and thiadiazoles were prepared starting from N′‐(3,4‐dihydronaphthalen‐1(2H)‐ylidene)hydrazinecarbothiohydrazide by reacting with different types of hydrazonoyl chlorides. In addition, 7‐(4‐chlorophenyl)‐5,6,6a,7‐tetrahydrobenzo [b]naphtha‐[1,2‐e][1,4]thiazepine reacted with hydrazonoyl halides to afford a new derivatives of 7‐(4‐chlorophenyl)‐14‐phenyl‐5,6,6a,7‐tetrahydro‐16H‐benzo[b]naphtho[1,2‐e][1,2,4]triazolo[4,3‐d][1,4]thiazepine. Structures of the newly synthesized compounds were elucidated on the basis of elemental analyses and spectral data.