81154-06-5

Upstream product

• 110-91-8 morpholine 
• 141-84-4 2-thioxo-4-thiazolidinone 
• 90-02-8 salicylaldehyde 
• 34709-44-9 E,Z-5-(2-hydroxyphenylmethylene)-4-oxo-2-thioxo-1,3-thiazolidine 
• 81154-12-3 (5Z)-5-(2-hydroxybenzylidene)-2-thioxo-1,3-thiazolidin-4-one 
• 145903-73-7 piperidine salt of (E,Z)-5-(2-hydroxyphenylmethylene)-4-oxo-2-thioxothiazolidine 

Relevant academic research and scientific papers

E,Z-5-Arylmethylene-4-oxo-2-thioxo-1,3-thiazolidine and 3,3'-Dithiobis-2H-1-benzopyran-2-one Derivatives and their Reactions with Some Amines

The reaction of 4-oxo-2-thioxo-1,3-thiazolidine (1) with salicylaldehyde (2) or its 5-bromo derivative (2b) in acetic acid and sodium acetate gave a mixture of E,Z- or E-5-arylmethylene-4-oxo-2-thioxo-1,3-thiazolidines (3a or b) and 3,3'-dithiobis-2H-1-benzopyran-2-ones (4a and b), respectively. Treatment of E,Z-thiazolidinone (3a) with benzylamine or morpholine in dioxane at room temperature afforded 3-benzylamino-2H-1-benzopyran-2-one (6a) or E,Z-2-thiazolin-4-one derivative (7b) together with the amine salt (8), respectively. Similar treatment of E-(3b) with benzylamine yielded the E,Z-2-thiazolin-4-one derivative (7a) and the disulfide (4b) as the major product. The disulfide (4a) reacted with benzylamine in cold dioxane to yield the disulfide derivative (10) in addition to 6a whereas in boiling dioxane in gave 2H-1-benzopyran-2-one derivatives (6a and b). On the other hand, when E-(3b) or 4a was treated with dicyclohexylamine in dioxane, it gave 4b as well as the amine salt (9) in the former case and 3-mercapto-2H-1-benzopyran-2-one (5, X = H) in the latter one. Structures of all products were evidenced by microanalytical and spectra data.

Reactions of 5-Arylmethylene-4-oxo-2-thioxothiazolidines with Amines

Piperidine, morpholine and benzylamine react with 5-arylmethylene-4-oxo-2-thioxothiazolidines (I) to give the corresponding piperidine (IIa-d), morpholine (IIe-f) and benzylamine (IIg) salts which on treatment with ethanol undergo decomposition to give the respective 2-piperidino- and 2-morpholino-4-oxo-2-thiazolines (III), and 2-benzylimino-4-oxothiazolidine (IVa).However, decomposition of IIa-d in the presence of an equimolar amount of morpholine gives mixtures of 2-piperidino- and 2-morpholino-4-oxo-2-thiazolines (III).Furthermore, decomposition of IIe, c and d inthe presence of an excess of a primary amine affords exclusively the respective 2-substituted-imino-4-oxo-thiazolidines (IV).Cleavage of 5-arylmethylene-3-methyl-4-oxo-2-thioxothiazolidines (Va-b and e-g) with excess of piperidine affords 1-(N-methylthiocarbamyl)piperidine (VI).The structures of II, III, IV and VI are based on analytical and spectral data.