Synthesis, Structure And Biological Activities Of 1,3-Thiazolidine Derivatives

The thiazole derivatives have been widely used in pesticidal and medicinal fields because of their good biological activities. Sixty-six 1,3-thiazolidine derivatives, fifty-six of which are novel compounds, were prepared based on 1,3-thiazolidine as the lead compound and their structures were confirmed by IR, ¹H NMR, MS and elemental analysis. Their crystal structures and biological activities were also studied. It may be summarized as follows:1. According to the literature method, 2-thiono-l,3-thiazolidine was prepared with ethanolamine and carbon bisulfide as raw materials and 2-oxo-1,3-thiazolidine was further prepared by the exchange reaction between the oxygen of chloroethanol and sulphur atom of 2-thiono-1,3-thiazolidine. A new route of preparing nematocide fosthiazate was designed with 2-oxo-1,3-thiazolidine and O,O-diethyl chlorido-phosphorothioate as starting materials, and fosthiazate was successfully obtained. The remarkable advantages of the designed route are mild reaction condition, simple operation, easy obtain of the raw materials, etc.2. Twenty-six 2-substituted-1,3-thiazolidine-3-carboxylates, twenty-four of which are novel compounds, were prepared from a condensation reaction of 2-substituted-1,3-thiazolidine and chloroformate catalyzed by Et₃N; The structure of the condensation products of 2-thiono-1,3-thiazolidine and chloroformate were proven to be 2-thiono-1,3-thiazolidine-3-carboxylate rather than the ester of mercaptothiazoline by single-crystal X-ray diffraction of representative compound, and it was found that the C-N bond length to carbonyl groups is longer than the C-N bond length of a typical acylamine group.