Synthesis, Anti‐Inflammatory, and Analgesic Activities of Derivatives of 4‐Hydroxy‐2‐benzoxazolone

Benzoxazolones are widely distributed in plants and are of increasing interest for a variety of pharmacological properties, such as detoxification, antibacterial, anti‐inflammatory, and analgesic activities and tranquilizers (Michaelidou and Hadjipavlou‐Litina, 2005; Doğruer et al., 1998). 4‐Hydroxy‐2‐benzoxazolone (HBOA) is one of the major bioactive compounds in traditional Chinese herb drug Acanthus ilicifolius (Peng and Long, 2006) which has obvious anti‐inflammatory and analgesic activities (Huo et al., 2004; Mani Senthil Kumar et al., 2008; Babu et al., 2001). In this research, we used 2‐nitroresorcinol as starting material to prepare HBOA with a novel “one‐pot‐way.” Derivatives of HBOA TC‐2∼TC‐4 were obtained via electrophilic reagents and reacted with corresponding primary amines to afford Schiff Base derivatives TC‐5∼TC‐10 for further study. Anti‐inflammatory and analgesic activities of those derivatives were determined by using carrageenan‐induced rat paw edema test. The analgesic activities of the derivatives were determined by the hot‐plate test.