Synthesis and Applications of α-Oxodithioesters

In this chapter, we present the synthesis of α-oxodithioesters and their applications for the synthesis of heterocyclic compounds. At first, we report the synthesis of 2-(methylthio)-3-(het) arylquinoxalines by the cyclocondensation of o-phenylenediamines with
-oxodithioesters catalyzed by p-toluenesulfonic acid (p-TSA) in toluene at 80°C. 2-Acylbenzoxazoles are formed when o-aminophenols react with α-oxodithioesters under similar reaction conditions. Besides, 4-methylthio-5-acylthiazoles are obtained when α-oxodithioesters are reacted with tosylmethyl isocyanide in aqueous alcoholic potassium hydroxide media. Similarly, a reaction between ethyl isocyanoacetate and α-oxodithioesters in ethanol in the presence of DBU-furnished ethyl 5-acylthiazole carboxylates. The p-TSA catalyzed cyclocondensation of anthranilamide with
-oxodithioesters in DMF at 120°C produced 2-acylquinazolin-4(3H)-ones. Finally, a reaction between α-oxodithioesters and anthranilamide in refluxing acetic acid formed 2-acyl-4H-benzo[d][1,3] thiazin-4-ones.