Synthesis and Chymotrypsin Inhibitory Activity of Substituted Oxazolones

A variety of oxazolones (3-18) with structural variation at C-2 and C-4 were synthesized and evaluated as chymotrypsin inhibitors. The synthesized compounds showed varying degree of chymotrypsin inhibitory activity ranging IC50 values from 12.62 ± 1.32 - 126.57 ± 1.06 μM, if compared to standard chymostatin (IC50 = 7.01 ± 0.1 μM). Compounds 3,9,10,13,14, and 15 have IC50 values 17.03 ± 0.78, 69.05 ± 1.48, 12.62 ± 1.32, 17.29 ± 0.93, 126.57 ± 1.06, and 31.55 ± 1.31 μM, respectively. This study reveals that the substitution of functional group (s) at C-2 and C-4 positions plays a vital role in the activity of this series of compounds. The size and electron donating or withdrawing effects of substituents influenced the activity.