الفهرس 
Chemistry of 4-oxo-thiazolidinesOnly 14 pages are availabe for public view
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Abstract
The present investigation deals with the reactions of 2-
(2,4-dioxo-thiazolidin-5-yl)acetic acid 1, its chloride 2 and
its methyl ester 3 with different aliphatic and aromatic
amines aiming to synthesize imidazolyl, thiazolyl,
benzoxazinonyl, quinazolinonyl and other derivatives of
2,4-dioxo-thiazolidines.
The acid 1 could be obtained from refluxing thiourea
with maleic anhydride in the presence of concentrated HCl.
When the acid 1 was reacted with bis-nucleophiles such as
o-phenylenediamine in refluxing ethanol for 2h., it produced
N-(2-aminophenyl)-2-(2,4-dioxo-thiazolidin-5-yl)acetamide
4. Cyclization of 4 by refluxing in an equimolar mixture of
HCl/CH3COOH for 5h. afforded 5-(1H-benzo[d]imidazol-2-
ylmethyl)-2,4-dioxo-thiazolidine 5.
Compound 5 can be obtained directly from the reaction
of 1 with o-phenylenediamine in refluxing phosphorus
oxychloride (POCl3) instead of ethanol and/or the reaction
of the acid chloride 2 with o-phenylenediamine in the
presence of triethylamine/dioxane (c.f. Scheme 1).