Quinazolin-2-ones having a spirohydantoin ring. II. Synthesis of several spiro(imidazolidine-4,4'(1'H)-quinazoline)-2,2',5(3'H)-triones via 5-hydroxyhydantoin derivatives.
Quinazolin-2-ones having a spirohydantoin ring. II. Synthesis of several spiro(imidazolidine-4,4'(1'H)-quinazoline)-2,2',5(3'H)-triones via 5-hydroxyhydantoin derivatives.
Reaction of 1-ethoxycarbonylisatin (1b) with urea gave 5-(2-ethoxycarbonylaminophenyl)-5-hydroxyhydantoin (4b) in a good yield. Treatment of 4b with several amines directly gave the corresponding spiro[imidazolidine-4, 4'(1'H)-quinazoline]-2, 2', 5(3'H)-trione derivatives (7a-d) in moderate yields. 3-Unsubstituted and 3-methylspiroquinazolin-2-one derivatives 7a, b were also synthesized from 5-ethoxy and 5-ethylthiohydantoins 5a, d, which in turn were easily obtained by the reaction of either ethanol or ethylmercaptan with 4b in the presence of a catalytic amount of sulfuric acid.
Biological activities and quantitative structure-activity relationships of spiro[imidazolidine-4,4'(1'H)-quinazoline]-2,2',5(3'H)-triones as aldose reductase inhibitors
A series of spiro[imidazolidine-4,4'(1'H)-quinazoline]-2,2',5(3'H)-triones were prepared and tested for aldose reductase inhibitory activity. The 6'-halogenated derivatives were found to be highly potent in vitro inhibitors of male rabbit lens aldose reductase and in vivo inhibitors of polyol accumulation in the sciatic nerves of galactosemic rats. Of these, (4R)-6'-chloro-3'-methylspiro[imidazolidine-4,4'(1'H)-quinazoline]-2,2',5(3'H)-trione (67) showed the most potent in vitro and in vivo activities. An oral dose of 3 g/kg of compound 67 caused neither death nor behavioral abnormality in the preliminary acute toxicity study using mice and rats. Compound 67 was selected as a candidate for further evaluation. The quantitative structure-activity relationships in this series are also discussed.