A series of novel compounds 7–43 were prepared via the condensation of enaminones 4a–h and the guanidines carbonate 6a–f. The structures of these newly synthesized compounds were confirmed by ¹H-NMR, MS, EA and IR. All the compounds were tested for their cytotoxic activity in vitro against human cancer cell lines including Ishikawa, A549, BEL-7404, SPC-A-01 and SGC-7901. Most of them showed moderate cytotoxic against the tested cell lines. Among them, the most potent compounds 9 and 30 exhibited more efficient activity against Ishikawa, A549.

The condensation of N-aryl thioureas with 3-bromo-acetylacetone in neutral solvent acetone not only led to 5-acetyl-4-methyl-2-(substituted anilino) thiazoles 3 but also 2-imino-3-(substituted phenyl)-4-methyl-5-acetyl-2,3-dihydrothiazoles 4. Further study found that different reaction solvents displayed an important role toward the ratio of aminothiazoles 3 and iminodihydrothiazoles 4, and the reaction scope was extended. A plausible mechanism involving solvent effect and in situ hydrobromic acid catalyzation was proposed. Some selected isomers exhibited moderate in vitro antiproliferative activity on human cervical cancer cell lines (Hela, Siha). J. Heterocyclic Chem., (2011).

A series of new unsymmetrical 3-phenyl-6-benzyl-1,2,4,5-tetrazine derivatives 10a-i were synthesized and characterized by IR, NMR, MS, and element analysis. The structures of 4a, 10c, 10d and 10h were analyzed by X-ray crystallography, which had intermolecular C-H-N, C-H-Cl, C-H-II and II-II interactions.