Synthesis Of Aminothiazole And Thiazolidinone Derivatives In Ionic Liquid

Ionic liquids are a new class of environment friendly medias. Due to their unique properties such as low vapor pressure, high stability, ease of recyclability, ionic liquids have been identified as possible alternatives to traditional solvents in a wide variety of organic reaction processes showing high yield, good selectivity, easy product isolation and less danger in many cases.The derivatives of aminothiazole and thiazolidinone are important heterocyclic compounds. They are of great value in medical field for their interesting biological properties and are also important intermediates in organic synthesis.The dissertation focuses on synthesis of aminothiazoles, thiazolidinones and their derivatives in ionic liquids. The thesis mainly includes three parts:In part one, the properties, compositions, preparations and applications in organic synthesis of ionic liquids are summarized.In part two, the synthetic methods of derivatives of aminothiazole and their applications in recent years are firstly summarized. Eighteen compounds of 2-aminothiazoles were synthesized by the cyclocondensation of a-bromomethyl ketones with TV-substituted thioureas in [emim]BF4, and four of them have not been reported yet. According to the experiment, ionic liquid can be recycled and reused effectively. This new synthesis of 2-aminothiazoles is with the advantage of mild conditions, time-saving and environment friendly.In part three, the synthetic methods of derivatives of thiazolidinone and their applications are also summarized firstly. The reaction of N-substituted thioureas withα-halo esters or acids in [emim]BF₄ was carried out to afford the mixture of two isomers of thiazolidiones. And when strart matericals were unsymmetrical N, N'-substituted thioureas, the products were with single structure, not the mixture of two isomers of corresponding thiazolidiones. Twelve couples of isomers and eight coumpounds with single structure were prepared with this synthetic method, and eight of them have not been reported in literature. Their structures were determined by testing the structure of hydration product. The machnism for this reaction was also proposed. It is a convenient and efficient method to synthesize the derivatives of thiazolidione in ionic liquild.Apart from these, bis(carboxyalkylmethyl) diselenides are prepared by the reaction of selenoamides with functionalizedα-halo esters or acids. A new and convenient synthesis of bis(carboxyalkylmethyl) diselenides was afforded.