Synthesis and cycloxygenase inhibitory properties of new naphthalene-methylsulfonamido, naphthalene-methylsulfonyl and tetrahydronaphthalen-methylsulfonamido compounds

We synthesized a series of new naphthalene derivatives: naproxen- and 6-methoxy naphthalene acetic acid-like 1–5. In these compounds the carboxylic function, typical of the classical NSAIDs, was replaced by a methylsulfonamido (1, 2 and 6a–c) or methylsulfonyl (3–5) group present in some selective COX-2 inhibitors. We also synthesized compounds 7 and 8 in which the naphthalene portion was substituted by tetrahydronaphthalene ring. Some of the new compounds were assayed for their enzymatic inhibitory activity towards cycloxygenase enzymes. Compounds 4 and 6b, at a concentration of 10 µM exhibit percentage inhibition values of 65%, 50% and 29%, 87% towards COX-2 and COX-1, respectively. The substitution of carboxylic group with a mehylsulfonamido or a methylsulfonyl groups does not allow to direct the selectivity versus to cycloxygenase enzymes.