Heterodiene synthesis. Synthesis of fused thiopyrano [2,3‐d]thiazole, Benzopyrano[3′,4′:4,5]thiopyrano[2,3‐d]thiazole and thiazolo[3,4‐c]triazine derivative

Abstract

5‐Salicylidenethiazolidine‐2,4‐dithione (1) reacts with acrylonitrile, N‐phenylmaleimide and dimethyl acet‐ylenedicarboxylate to afford the fused thiopyrano[2,3‐d]thiazolidinethione derivatives 2, 4 and 6, respectively. The salicylidene derivative 1 reacts with ethyl acrylate and malononitrile to afford the fused [1]benzopyrano[3′,4′:4,5]thiopyrano[2,3‐d]thiazoles 3 and 9, respectively. 4‐Phenylhydrazono‐2‐thiazolidinethione (11) reacts with ethyl bromoacetate and/or phenacyl bromide to yield the fused thiazolo[3,4‐c]triazines 13 and 14.

Facile synthesis of new (Z)-6-arylmethylidene-1,3,4-thiadiazin-5(6H)-one derivatives

“…They have been widely used as versatile intermediates for the synthesis of nitriles, amino acids, α-thio acids [1], and thiazoles [2][3][4]. In addition, 3-aryl-2-sulfanylpropenoic acids are known as antidotes for heavy metal poisoning [5][6][7].…”