Derivatization of enolic OH of piroxicam: a comparative study on esters and sulfonates

• Autor(a) principal: Jayaselli,J.
• Data de Publicação: 2008
• Outros Autores: Cheemala,J. Manila Sagar, Geetha Rani,D. P., Sarbani Pal
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532008000300019
• topic: piroxicam; esters; sulfonates; cyclooxygenase

A number of ester and sulfonate derivatives of piroxicam were prepared via acylation/sulfonation of the enolic OH of piroxicam. All the compounds were evaluated for their chemical stability and cyclooxygenase inhibiting properties. Data suggested that esters could be useful for the development of potential prodrugs. The sulfonate derivatives prepared for the first time were found to be stable. One of them showed a moderately selective COX-2 inhibition over COX-1 and would have lower gastrointestinal side effects than piroxicam due to the masked enolic OH group. A plausible mechanism for the acylation/sulfonation process has been proposed that involves participation of the pyridine moiety of piroxicam. Molecular structure of one of the ester was established for the first time by the crystal structure analysis from X-ray powder data.