One-pot synthesis of 5-phenylimino, 5-thieno or 5-oxo-1,2,3-dithiazoles and evaluation of their antimicrobial and antitumor activity

Synthesis of novel heterocyclic fused pyrimidin-4-one derivatives from imino-1,2,3-dithiazoles

“…Following the usual methods, 24 treatment of commercially available ethyl 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylate (1) with 4,5-dichloro-1,2,3-dithiazolium chloride (Appel's salt) (2) in dichloromethane at room temperature afforded 68% of the corresponding iminodithiazole (3) (Scheme 3). The presence of the fused cyclohexane ring avoids unwanted addition of Appel's salt at position C-5 of the thiophene.…”

“…We found that standard methods at room temperature 24 applied to the preparation of 2-Niminodithiazolothiophene derivatives led to a complex mixture of polymeric oily compounds resulting from electrophilic substitution at C-5 of the thiophene ring by N-1 of Appel's salt (2). Nevertheless, condensation of the starting amino ester (8) with one equivalent of Appel's salt (2) in dichloromethane at low temperature (-20 °C) followed by addition of pyridine (2 equiv.)…”

“…As a part of our ongoing research studies concerning the preparation and biological evaluation of sulphur and nitrogen-containing novel heterocycles, we have already been involved in exploiting the potential synthetic applications of 5-arylimino 4-chloro-5H-1,2,3-dithiazoles 24 . Kim and co-workers 25,26 followed by us reported the conversion of methyl 3-N-(4-chloro-5H-1,2,3-dithiazol-5-ylidene)thiophene-2-carboxylate V with various alkyl and aromatic diamines into thieno[3,2-d]pyrimidin-4-one derivatives I, II, III, IV (Scheme 2.)…”

Sulfur monochloride in organic synthesis

“…It has been shown that the reaction can occur with readily available ethanone oximes of different structure containing aliphatic, aromatic and heteroaromatic substituents and functional groups. 120 Studies have shown that 1,2,3-dithiazolium salts 171 thus obtained are unstable; therefore, they are in situ introduced into further transformations. It has been demonstrated that 5-oxo-(172), 5-thioxo-(173) and 5-phenylimino-1,2,3-dithiazoles (174) are selectively formed in moderate to high yields by means of the one-pot reaction of ethanone oximes with sulfur monochloride and pyridine in acetonitrile followed by treatment with the corresponding nucleophile (formic acid, thioacetamide or aniline) (Scheme 88).…”

(Z)-2-(4-Chloro-5H-1,2,3-dithiazol-5-ylideneamino)-6-ethoxy-4-phenylpyridine-3,5-dicarbonitrile

“…N-Aryl-1,2,3-dithiazolimines show interesting antitumour [1], antifungal [2], antibacterial [3], and herbicidal activities [4]. Furthermore, these compounds are useful precursors for difficult to access cyano substituted heteroarenes [3,5].…”