Study of the effect of solvent and different Lewis acids in one pot multicomponent microwave assisted reaction for the chemoselective generation of 1.4-thiazepan-3 -ones and 4-thiazolidinones

QUIROGA, A. A.; COSTILLA I. O.; LORENZO F. J. ; CALMELS J. J; VILLAFAIN D.; MANDOLESI S. D.; DACCORSO N. B; OCAMPO R. A.

Congreso; ECSOC 21; 2018

With the aim of exploring the best reaction conditions for the diastereoselective synthesis of the 1,4-thiazepan-3-ones (4) and 4-thiazolidinones (5), we have studied the effect on solvent variation and the aggregation of AlCl3 and different zeolites as Lewis acid catalysts to thethree-component microwave assisted reaction between 2,3:4,5-di-O-isopropylidene-β-D-arabino-hexos-2-ulo-2,6-pyranose (1), benzotiazole (3) and thioglycolic acid (2). Based on the results of previous studies of our group, we discuss here two microwave assisted methods: multicomponent reaction in the presence of the catalysts (Method A) and sequential reaction with generation of the corresponding intermediates and subsequent addition of the catalystscoordinated to thioglycolic acid (Method B).