Synthesis Of Spiro-Heterocycle Compounds Of Oxazole, Thiazole And Quinoline Derivatives

The paper focus on the synthesis of a number of novel spiroheterocycles by the 1,3-dipolar cycloaddition reaction in the presence of catalysts.4-Arylidene-2-phenyloxazol-5(4H)-one, which synthesized by hippuric acid andaromatic aldehydes, as azomethine ylides reacted with isatin and sarcosine or prolinein the presence of montmorillonite K10 to give the 16 target compounds via 'one pot'procedure. Compared with the different catalysts, we found that montmoillonite K10was an efficient catalyst.We also used 5-arylidene-2-thioxothiazolidin-4-one which was synthesized byrhodanine and aromatic aldehydes reacted with azomethine ylide generated fromsarcosine and isatin to obtain the 11 target compounds in the presence ofBaCl₂/montmorillonite K10. Using this new tape catalyst, the three componentreaction possess the valuable features of higher yields and shorter reaction time.In the end, we got the 6 spirocompounds via the four components reaction whichcontains rhodanine, aromatic aldehydes, acenaphthylene-1, 2-dione and sarcosine inthe presence of Magnesium sulfate and triethylamine.33 Spiroheterocycle compounds were synthesized in this paper. All the targetcompounds's structures were confirmed by the IR, elemental analyses and ^H NMR.Some of them were further confirmed by ¹³C NMR and hi-mass spectra. The stereoconformations of 2 new parent heterocycles were achieved by X-ray single crystalanalyses. The retro-cycloaddition reaction of cycloaddition style was determined byX-ray single crystal analyses too. At the same time, X-ray single crystal analyses further confirmed the catalyst's validity. The regioselectivity and steroselectivity of thereaction was also discussed.