1-(Benzothiazol-2-yl)-3-phenylthiourea 2 was prepared and treated with hydrazonoyl chlorides 3a-e to yield the corresponding 5-(benzothiazol-2-ylimino)-1,3,4-thiadiazole derivatives 6a-e, respectively. Reaction of the thiourea derivative 2 with ethyl 2-chloro-3-oxobutanoate 9 afforded the corresponding 2-(benzothiazol-2-ylimino)thiazole-5-carboxylate derivative 11. The newly synthesized heterocyclic derivatives were confirmed from their elemental and spectral analyses.