Application of thiolate salts in the synthesis of heterocyclic compounds via multicomponent reactions

The available approaches to the synthesis of tetrasubstituted thiophenes include 5-acetyl-4-amino-2-methylsulfanyl-3-carbonitrile relies on generating inorganic salt of 2,2-dicyano-1,1-dithiolate from malononitrile and carbon disulfide, following reaction with α-haloketones in presence of base at heat condition.1 However, these approaches suffer from significant limitations in terms of harsh reaction conditions, multitude operational steps, temperature adjustment, low yields, strong base, and difficult purification.In line with the above statements, inventing a protocol that concomitantly lacks catalyst, acidic or basic media, and heating, which are three necessary obligations in all documented procedures for the synthesis of thiophene frameworks, would be a great innovation. Herein, the present study breaks the aforementioned boundary in a two-step reaction, harnessing organic salt 5 generated by cyclic thioureas and di(methylsulfanyl)methylenemalononitrile (Scheme 1).

کلیدواژه ها:

Ketene dithioacetal ، Triethylammonium thiolate ، Methyl iodide ، o-Phenylenediamine ، Quinoxaline ، Cyclic thiourea ، Thiophenes ، Indandione Motif ، Multicomponent reactions