Synthesis of Pyrimidine-4-thiones and Thiazoles from TMG Adducts and Isothiocyanates

Heterocyclic compounds, such as pyrimidines play an important role in the field of drugs, agrochemicals, and biological processes. In recent years, pyrimidines and pyrimidinethiones have been the subject of numerous pharmacological studies [1]. Thiazole is a well-known five-membered heterocycle that is present in many naturaland synthetic products with a broad range of biological activities such as antimicrobial, antipyretic, antiparasitic, antihistaminic, and antiviral properties [2]. Herein, we report a simple procedure for the synthesis of alkyl 2-(dimethylamino)-1,4-diphenyl-6-thioxo-1,6-dihydropyrimidine-5-carboxylates 4 and 2-(dimethylamino)thiazoles 5 via the three-component reaction of tetramethylguanidine (TMG, 1), ethyl phenylpropiolate 2, and aryl isothiocyanates 3. The reactions proceed smoothly and the products are obtained in moderate to good yields. Various features of these reactions are presented and discussed