Selective and efficient Cu-catalyzed 1,3-bipolar cycloaddition of propargylthiobenzoxazoline and aryl azides

It was selectively carried out synthesis of S-propargylthiobenzoxazoline (2). An effective synthesis method of 2-propargylthiobenzoxazoline was found and a cheap and convenient method of synthesis of new benzoxazole-triazole hybrid molecules (3-9) was developed by carrying out 1,3-bipolar cycloaddition reactions of the obtained 2-propargyl-derivative with some aromatic azides. Factors influencing the course and direction of the reaction (catalyst nature, ratio of reagents, reaction temperature and duration) have been identified. The IR-, 1H and 13C NMR spectra of the obtained substances were analyzed and it was proved that they correspond to their structures.