Given the ability of 1,5-dicarbonyl compounds to emerge in the presence of ammonia, urea and its derivatives of N-containing heterocyclic compounds, possibility of сyclization 2-pentene- and pentane-1,5-diones and their dihalogensubstituted analogues with thioacetamide. When boiling pentenedions with thioacetamide in ethanol occurs condensation with the participation of oxo-function, free of the pairing, with the formation of 5-oxo-1,3,5-triarylpent3-enilidenthioacetamide with access 63-80%; pentanedions when heated in xylene for 20–35 minutes give heterocyclic products with the participation of the propanonilic fragment - substituted 4.5-dihydrothiazoles with access 68-73%.Unlike dichloro(bromine) pentanedions forming bisthiazoles with thioacetamide, when heated, 2,4-dichloro-1,3,5-triphenyl-2-pentene-1,5-dione with the latest in p-xylene bisproduct is not formed; occurs 3(2-methyl-4-phenylthiazol-5-yl)-2-chloro-1,3-diphenylpropenone with the release of 81%. ?,?-Unsaturated fragment or sedentary chlorine atom with the double bond did not participate in the reaction with thioacetamide; a chlorine atom form a multiple relationship as opposed to such, discussed above unsubstituted analogues, has low reactivity. Structure of products installed on the basis of the data of the NMR and IR spectroscopy. The reaction of ?-halogen-1,5-diketones with thioacetamide is of interest as a convenient method for the synthesis of previously hardto-substituted thiazoles.