Determination of Acid Dissociation Constants of Some 2-(3H) –Benzoxazolone Derivatives by UV–Vis Spectrophotometry

The acid dissociation constant values of some 2-(3H)-benzoxazolone derivatives were determined in buffered solutions by using the UV-Vis spectrophotometric method. These compounds have benzoxazolone core structures with arylpiperazine substituents and have been investigated for their anti-inflammatory and analgesic activities. The 2-(3H)-benzoxazolone derivatives showed acid dissociation constant values ranging from 8.26 to 9.28. The 5-chloro-2-(3H)-benzoxazolone derivatives exhibit higher acidity than the 2-(3H)-benzoxazolone derivatives. Additionally, a comparison of 5-chloro-2-(3H)-benzoxazolone derivatives showed that derivatives with halogen-containing R2 groups exhibited higher acidity. The findings of this study also suggest that UV–Vis spectrophotometry is one of the most effective techniques for measuring acid dissociation constant values.