A thiazole derivative can be easily prepared, e.g., front an alpha-thiocyanatoketone and a nitrogen nucleophile. In this work, alpha-bromopropiophenone was chosen as a starting compound. Since the carbonyl group facilitates nucleophilic substitution, bromine can be simply replaced with the thiocyanato group. The following reaction with hydroxylamine hydrochloride provides an intermediate, which undergoes a ring closure reaction. Finally, 3-hydroxy-5-methyl-4-phenylthiazol-2(3H)-iminium chloride 4a or 1-hydroxy-4-methyl-5-phenyl-1,3-dihydro-2H-imidazole-2-thione 5a arises depending on the presence of a base. lit the next part, this interesting phenomenon was successfully investigated on selenium derivatives as well. All prepared substances have not been described in the literature yet.
