Studies on heterocyclic compounds: 1,3-thiazolidin-4-one derivatives. V. Pharmacological activity of substituted 2-phenyl-3-(N,N-dimethylaminoprophyl)-1,3-thiazolidin-4-one .

The following 2-substituted phenyl-3-(N,N-dimethylaminopropyl)-1,3-thiazolidin-4-one of general formula (A): formula: see text] where: X = H (I), 3-F (II), 3-Cl (III), 3-Br (IV), 3-CH3 (V), 3-OCH3 (VI), 3-NO2 (VII), 4-F (VIII), 4-Cl (IX), 4-Br (X), 4-CH3 (XI), 4-OCH3 (XII), 4-NO2 (XIII) were prepared and tested for antihistamine activity. The synthetic procedure involves the cyclocondensation of the appropriate Schiff base with thioglycolic acid in refluxing dry benzene. The compounds herein presented were tested for their ability to inhibit the contraction inducted by histamine 5.10(-7) M "in vitro", on guinea pig ileum. The results are reported as contraction of test compound causing 50% of submaximal contraction induced by histamine (IC50), and related to mepyramine as control. The results of the antihistamine tests showed an interesting degree of activity of some of the new thiazolidinone-derivatives. Compounds II, III, V, X, and XI showed IC50 values near the value of the control, compound XI being the most active. These compounds seem to be worthy of further investigation.