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.