4-aryl-6,6-dimethyl-1,2,3,4,5,6,7,8-octahydroquinazoline-2,5-diones: synthesis, chromatographic resolution and pharmacological activity.

In this study, a series of 4-aryl-6,6-dimethyl-1,2,3,4,5,6,7,8- octahydroquinazoline-2,5-diones were synthesized by condensing urea with 4,4-dimethyl-1,3-cyclohexanedione and appropriate aromatic aldehydes according to the Biginelli reaction. The structures of the compounds were characterized by spectroscopic methods. The racemic compounds were resolved into the enantiomers by HPLC on amylose tris(3,5-dimethylphenylcarbamate) (Chiralpak AD). The compounds were tested in vitro for their calcium antagonistic activities. BaCl2-induced contractions of rat ileum were inhibited dose-dependently. Compounds 3 and 5 exerted weak calcium antagonistic activity on smooth muscles compared with the standard, nicardipine.