Synthesis and Reactivity of Phenylthiourea Derivatives: An Efficient Synthesis of New Thiazole‐Based Heterocycles

Abstract

Reaction of 1‐(5‐acetyl‐4‐methylthiazol–2‐yl)–3‐phenylthiourea 2 with hydrazonoyl chlorides (3a, 3b, 3c, 3d, 3e, 3f) and 9 yielded the corresponding (thiazolyl)imino–1,3,4‐thiadiazole derivatives (6a, 6b, 6c, 6d, 6e, 6f) and 12, respectively. Reaction of 2 with ethyl chloroacetate 13 gave (thiazolyl)imino‐1,3‐thiazolidin‐4‐one derivative 15, which upon condensation with aromatic aldehyde derivatives yielded the 5‐benzylidene derivatives (16a, 16b). In addition, treatment of 2 with 3‐chloropenta‐2,4‐dione 17 afforded the corresponding (thiazolyl)imino‐1,3‐thiazole derivative 19. The newly synthesized compounds were confirmed from their elemental analyses and spectral data.

Synthesis of Pyrazolo[1,5‐a][1,3,5]triazine, Pyrazolo[1,5‐a]pyrimidine, and Imidazo[1,2‐b]pyrazole Derivatives Based on Imidazo[2,1‐b]thiazole Moiety

“…In view of the aforementioned biological importance and in continuation of our interest in the synthesis of various heterocycles and its pharmacological properties , we report herein a facile synthetic strategy for synthesis of pyrazole, pyrazolo[1,5‐ a ][1,3,5]triazine, pyrazolo[1,5‐ a ]pyrimidines, imidazo[1,2‐ b ]pyrazole derivatives, and Schiff‐based derivatives linked to imidazo[2,1‐ b ]thiazole. The biological activities of the synthesized products will be reported in the extended work.…”